// dear imgui, v1.80 WIP
// (tables and columns code)

/*

Index of this file:

// [SECTION] Tables: BeginTable, EndTable, etc.
// [SECTION] Tables: Sorting
// [SECTION] Tables: Headers
// [SECTION] Tables: Context Menu
// [SECTION] Tables: Settings (.ini data)
// [SECTION] Tables: Garbage Collection
// [SECTION] Tables: Debugging
// [SECTION] Columns, BeginColumns, EndColumns, etc.

*/

#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
#define _CRT_SECURE_NO_WARNINGS
#endif

#include "imgui.h"
#ifndef IMGUI_DISABLE

#ifndef IMGUI_DEFINE_MATH_OPERATORS
#define IMGUI_DEFINE_MATH_OPERATORS
#endif
#include "imgui_internal.h"

// System includes
#if defined(_MSC_VER) && _MSC_VER <= 1500 // MSVC 2008 or earlier
#include <stddef.h>     // intptr_t
#else
#include <stdint.h>     // intptr_t
#endif

//-------------------------------------------------------------------------
// Warnings
//-------------------------------------------------------------------------

// Visual Studio warnings
#ifdef _MSC_VER
#pragma warning (disable: 4127)     // condition expression is constant
#pragma warning (disable: 4996)     // 'This function or variable may be unsafe': strcpy, strdup, sprintf, vsnprintf, sscanf, fopen
#if defined(_MSC_VER) && _MSC_VER >= 1922 // MSVC 2019 16.2 or later
#pragma warning (disable: 5054)     // operator '|': deprecated between enumerations of different types
#endif
#endif

// Clang/GCC warnings with -Weverything
#if defined(__clang__)
#if __has_warning("-Wunknown-warning-option")
#pragma clang diagnostic ignored "-Wunknown-warning-option"         // warning: unknown warning group 'xxx'                      // not all warnings are known by all Clang versions and they tend to be rename-happy.. so ignoring warnings triggers new warnings on some configuration. Great!
#endif
#pragma clang diagnostic ignored "-Wunknown-pragmas"                // warning: unknown warning group 'xxx'
#pragma clang diagnostic ignored "-Wold-style-cast"                 // warning: use of old-style cast                            // yes, they are more terse.
#pragma clang diagnostic ignored "-Wfloat-equal"                    // warning: comparing floating point with == or != is unsafe // storing and comparing against same constants (typically 0.0f) is ok.
#pragma clang diagnostic ignored "-Wformat-nonliteral"              // warning: format string is not a string literal            // passing non-literal to vsnformat(). yes, user passing incorrect format strings can crash the code.
#pragma clang diagnostic ignored "-Wsign-conversion"                // warning: implicit conversion changes signedness
#pragma clang diagnostic ignored "-Wzero-as-null-pointer-constant"  // warning: zero as null pointer constant                    // some standard header variations use #define NULL 0
#pragma clang diagnostic ignored "-Wdouble-promotion"               // warning: implicit conversion from 'float' to 'double' when passing argument to function  // using printf() is a misery with this as C++ va_arg ellipsis changes float to double.
#pragma clang diagnostic ignored "-Wenum-enum-conversion"           // warning: bitwise operation between different enumeration types ('XXXFlags_' and 'XXXFlagsPrivate_')
#pragma clang diagnostic ignored "-Wdeprecated-enum-enum-conversion"// warning: bitwise operation between different enumeration types ('XXXFlags_' and 'XXXFlagsPrivate_') is deprecated
#pragma clang diagnostic ignored "-Wimplicit-int-float-conversion"  // warning: implicit conversion from 'xxx' to 'float' may lose precision
#elif defined(__GNUC__)
#pragma GCC diagnostic ignored "-Wpragmas"                          // warning: unknown option after '#pragma GCC diagnostic' kind
#pragma GCC diagnostic ignored "-Wformat-nonliteral"                // warning: format not a string literal, format string not checked
#pragma GCC diagnostic ignored "-Wclass-memaccess"                  // [__GNUC__ >= 8] warning: 'memset/memcpy' clearing/writing an object of type 'xxxx' with no trivial copy-assignment; use assignment or value-initialization instead
#endif

//-----------------------------------------------------------------------------
// [SECTION] Tables: BeginTable, EndTable, etc.
//-----------------------------------------------------------------------------
// Typical call flow: (root level is public API):
// - BeginTable()                               user begin into a table
//    | BeginChild()                            - (if ScrollX/ScrollY is set)
//    | TableBeginApplyRequests()               - apply queued resizing/reordering/hiding requests
//    | - TableSetColumnWidth()                 - apply resizing width (for mouse resize, often requested by previous frame)
//    |    - TableUpdateColumnsWeightFromWidth()- recompute columns weights (of stretch columns) from their respective width
// - TableSetupColumn()                         user submit columns details (optional)
// - TableSetupScrollFreeze()                   user submit scroll freeze information (optional)
// - TableUpdateLayout() [Internal]             automatically called by the FIRST call to TableNextRow() or TableHeadersRow(): lock all widths, columns positions, clipping rectangles
//    | TableUpdateDrawChannels()               - setup ImDrawList channels
//    | TableUpdateBorders()                    - detect hovering columns for resize, ahead of contents submission
//    | TableDrawContextMenu()                  - draw right-click context menu
//-----------------------------------------------------------------------------
// - TableHeadersRow() or TableHeader()         user submit a headers row (optional)
//    | TableSortSpecsClickColumn()             - when left-clicked: alter sort order and sort direction
//    | TableOpenContextMenu()                  - when right-clicked: trigger opening of the default context menu
// - TableGetSortSpecs()                        user queries updated sort specs (optional, generally after submitting headers)
// - TableNextRow()                             user begin into a new row (also automatically called by TableHeadersRow())
//    | TableEndRow()                           - finish existing row
//    | TableBeginRow()                         - add a new row
// - TableSetColumnIndex() / TableNextColumn()  user begin into a cell
//    | TableEndCell()                          - close existing column/cell
//    | TableBeginCell()                        - enter into current column/cell
// - [...]                                      user emit contents
//-----------------------------------------------------------------------------
// - EndTable()                                 user ends the table
//    | TableDrawBorders()                      - draw outer borders, inner vertical borders
//    | TableReorderDrawChannelsForMerge()      - merge draw channels if clipping isn't required
//    | EndChild()                              - (if ScrollX/ScrollY is set)
//-----------------------------------------------------------------------------

// Configuration
static const int TABLE_DRAW_CHANNEL_BG0 = 0;
static const int TABLE_DRAW_CHANNEL_BG1_FROZEN = 1;
static const int TABLE_DRAW_CHANNEL_UNCLIPPED = 2;                  // When using ImGuiTableFlags_NoClip
static const float TABLE_BORDER_SIZE                     = 1.0f;    // FIXME-TABLE: Currently hard-coded because of clipping assumptions with outer borders rendering.
static const float TABLE_RESIZE_SEPARATOR_HALF_THICKNESS = 4.0f;    // Extend outside inner borders.
static const float TABLE_RESIZE_SEPARATOR_FEEDBACK_TIMER = 0.06f;   // Delay/timer before making the hover feedback (color+cursor) visible because tables/columns tends to be more cramped.

// Helper
inline ImGuiTableFlags TableFixFlags(ImGuiTableFlags flags, ImGuiWindow* outer_window)
{
    // Adjust flags: set default sizing policy
    if ((flags & (ImGuiTableFlags_ColumnsWidthStretch | ImGuiTableFlags_ColumnsWidthFixed)) == 0)
        flags |= (flags & ImGuiTableFlags_ScrollX) ? ImGuiTableFlags_ColumnsWidthFixed : ImGuiTableFlags_ColumnsWidthStretch;

    // Adjust flags: MultiSortable automatically enable Sortable
    if (flags & ImGuiTableFlags_MultiSortable)
        flags |= ImGuiTableFlags_Sortable;

    // Adjust flags: disable Resizable when using SameWidths (done above enforcing BordersInnerV)
    if (flags & ImGuiTableFlags_SameWidths)
        flags = (flags & ~ImGuiTableFlags_Resizable) | ImGuiTableFlags_NoKeepColumnsVisible;

    // Adjust flags: enforce borders when resizable
    if (flags & ImGuiTableFlags_Resizable)
        flags |= ImGuiTableFlags_BordersInnerV;

    // Adjust flags: disable NoHostExtendY if we have any scrolling going on
    if ((flags & ImGuiTableFlags_NoHostExtendY) && (flags & (ImGuiTableFlags_ScrollX | ImGuiTableFlags_ScrollY)) != 0)
        flags &= ~ImGuiTableFlags_NoHostExtendY;

    // Adjust flags: NoBordersInBodyUntilResize takes priority over NoBordersInBody
    if (flags & ImGuiTableFlags_NoBordersInBodyUntilResize)
        flags &= ~ImGuiTableFlags_NoBordersInBody;

    // Adjust flags: disable saved settings if there's nothing to save
    if ((flags & (ImGuiTableFlags_Resizable | ImGuiTableFlags_Hideable | ImGuiTableFlags_Reorderable | ImGuiTableFlags_Sortable)) == 0)
        flags |= ImGuiTableFlags_NoSavedSettings;

    // Inherit _NoSavedSettings from top-level window (child windows always have _NoSavedSettings set)
#ifdef IMGUI_HAS_DOCK
    ImGuiWindow* window_for_settings = outer_window->RootWindowDockStop;
#else
    ImGuiWindow* window_for_settings = outer_window->RootWindow;
#endif
    if (window_for_settings->Flags & ImGuiWindowFlags_NoSavedSettings)
        flags |= ImGuiTableFlags_NoSavedSettings;

    return flags;
}

ImGuiTable* ImGui::TableFindByID(ImGuiID id)
{
    ImGuiContext& g = *GImGui;
    return g.Tables.GetByKey(id);
}

ImGuiTable::ImGuiTable()
{
    memset(this, 0, sizeof(*this));
    SettingsOffset = -1;
    InstanceInteracted = -1;
    LastFrameActive = -1;
    LastResizedColumn = -1;
    ContextPopupColumn = -1;
    ReorderColumn = -1;
    ResizedColumn = -1;
    AutoFitSingleStretchColumn = -1;
    HoveredColumnBody = HoveredColumnBorder = -1;
}

ImGuiTable::~ImGuiTable()
{
    IM_FREE(RawData);
}

// (Read carefully because this is subtle but it does make sense!)
// About 'outer_size', its meaning needs to differ slightly depending of if we are using ScrollX/ScrollY flags:
//   X:
//   - outer_size.x < 0.0f  ->  right align from window/work-rect maximum x edge.
//   - outer_size.x = 0.0f  ->  auto enlarge, use all available space.
//   - outer_size.x > 0.0f  ->  fixed width
//   Y with ScrollX/ScrollY: using a child window for scrolling:
//   - outer_size.y < 0.0f  ->  bottom align
//   - outer_size.y = 0.0f  ->  bottom align, consistent with BeginChild(). not recommended unless table is last item in parent window.
//   - outer_size.y > 0.0f  ->  fixed child height. recommended when using Scrolling on any axis.
//   Y without scrolling, we output table directly in parent window:
//   - outer_size.y < 0.0f  ->  bottom align (will auto extend, unless NoHostExtendV is set)
//   - outer_size.y = 0.0f  ->  zero minimum height (will auto extend, unless NoHostExtendV is set)
//   - outer_size.y > 0.0f  ->  minimum height (will auto extend, unless NoHostExtendV is set)
// About 'inner_width':
//   With ScrollX:
//   - inner_width  < 0.0f  ->  *illegal* fit in known width (right align from outer_size.x) <-- weird
//   - inner_width  = 0.0f  ->  fit in outer_width: Fixed size columns will take space they need (if avail, otherwise shrink down), Stretch columns becomes Fixed columns.
//   - inner_width  > 0.0f  ->  override scrolling width, generally to be larger than outer_size.x. Fixed column take space they need (if avail, otherwise shrink down), Stretch columns share remaining space!
//   Without ScrollX:
//   - inner_width          ->  *ignored*
// Details:
// - If you want to use Stretch columns with ScrollX, you generally need to specify 'inner_width' otherwise the concept
//   of "available space" doesn't make sense.
// - Even if not really useful, we allow 'inner_width < outer_size.x' for consistency and to facilitate understanding
//   of what the value does.
bool    ImGui::BeginTable(const char* str_id, int columns_count, ImGuiTableFlags flags, const ImVec2& outer_size, float inner_width)
{
    ImGuiID id = GetID(str_id);
    return BeginTableEx(str_id, id, columns_count, flags, outer_size, inner_width);
}

// For reference, the average total _allocation count_ for a table is:
// + 0 (for ImGuiTable instance, we are pooling allocations in g.Tables)
// + 1 (for table->RawData allocated below)
// + 1 (for table->ColumnsNames, if names are used)
// + 1 (for table->Splitter._Channels)
// + 2 * active_channels_count (for ImDrawCmd and ImDrawIdx buffers inside channels)
// Where active_channels_count is variable but often == columns_count or columns_count + 1, see TableUpdateDrawChannels() for details.
// Unused channels don't perform their +2 allocations.
static void TableBeginInitMemory(ImGuiTable* table, int columns_count)
{
    // Allocate single buffer for our arrays
    ImSpanAllocator<3> span_allocator;
    span_allocator.ReserveBytes(0, columns_count * sizeof(ImGuiTableColumn));
    span_allocator.ReserveBytes(1, columns_count * sizeof(ImS8));
    span_allocator.ReserveBytes(2, columns_count * sizeof(ImGuiTableCellData));
    table->RawData = IM_ALLOC(span_allocator.GetArenaSizeInBytes());
    span_allocator.SetArenaBasePtr(table->RawData);
    span_allocator.GetSpan(0, &table->Columns);
    span_allocator.GetSpan(1, &table->DisplayOrderToIndex);
    span_allocator.GetSpan(2, &table->RowCellData);

    memset(table->RowCellData.Data, 0, table->RowCellData.size_in_bytes());
    for (int n = 0; n < columns_count; n++)
    {
        ImGuiTableColumn* column = &table->Columns[n];
        *column = ImGuiTableColumn();
        column->DisplayOrder = table->DisplayOrderToIndex[n] = (ImS8)n;
        column->AutoFitQueue = column->CannotSkipItemsQueue = (1 << 3) - 1; // Fit for three frames
    }
}

bool    ImGui::BeginTableEx(const char* name, ImGuiID id, int columns_count, ImGuiTableFlags flags, const ImVec2& outer_size, float inner_width)
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* outer_window = GetCurrentWindow();
    if (outer_window->SkipItems) // Consistent with other tables + beneficial side effect that assert on miscalling EndTable() will be more visible.
        return false;

    // Sanity checks
    IM_ASSERT(columns_count > 0 && columns_count <= IMGUI_TABLE_MAX_COLUMNS && "Only 1..64 columns allowed!");
    if (flags & ImGuiTableFlags_ScrollX)
        IM_ASSERT(inner_width >= 0.0f);

    // If an outer size is specified ahead we will be able to early out when not visible. Exact clipping rules may evolve.
    const bool use_child_window = (flags & (ImGuiTableFlags_ScrollX | ImGuiTableFlags_ScrollY)) != 0;
    const ImVec2 avail_size = GetContentRegionAvail();
    ImVec2 actual_outer_size = CalcItemSize(outer_size, ImMax(avail_size.x, 1.0f), use_child_window ? ImMax(avail_size.y, 1.0f) : 0.0f);
    ImRect outer_rect(outer_window->DC.CursorPos, outer_window->DC.CursorPos + actual_outer_size);
    if (use_child_window && IsClippedEx(outer_rect, 0, false))
    {
        ItemSize(outer_rect);
        return false;
    }

    // Acquire storage for the table
    ImGuiTable* table = g.Tables.GetOrAddByKey(id);
    const bool table_is_new = (table->ID == 0);
    const int instance_no = (table->LastFrameActive != g.FrameCount) ? 0 : table->InstanceCurrent + 1;
    const ImGuiID instance_id = id + instance_no;
    const ImGuiTableFlags table_last_flags = table->Flags;
    if (instance_no > 0)
        IM_ASSERT(table->ColumnsCount == columns_count && "BeginTable(): Cannot change columns count mid-frame while preserving same ID");

    // Fix flags
    flags = TableFixFlags(flags, outer_window);

    // Initialize
    table->ID = id;
    table->Flags = flags;
    table->InstanceCurrent = (ImS16)instance_no;
    table->LastFrameActive = g.FrameCount;
    table->OuterWindow = table->InnerWindow = outer_window;
    table->ColumnsCount = columns_count;
    table->IsInitializing = false;
    table->IsLayoutLocked = false;
    table->InnerWidth = inner_width;
    table->OuterRect = outer_rect;
    table->WorkRect = outer_rect;

    // When not using a child window, WorkRect.Max will grow as we append contents.
    if (use_child_window)
    {
        // Ensure no vertical scrollbar appears if we only want horizontal one, to make flag consistent
        // (we have no other way to disable vertical scrollbar of a window while keeping the horizontal one showing)
        ImVec2 override_content_size(FLT_MAX, FLT_MAX);
        if ((flags & ImGuiTableFlags_ScrollX) && !(flags & ImGuiTableFlags_ScrollY))
            override_content_size.y = FLT_MIN;

        // Ensure specified width (when not specified, Stretched columns will act as if the width == OuterWidth and
        // never lead to any scrolling). We don't handle inner_width < 0.0f, we could potentially use it to right-align
        // based on the right side of the child window work rect, which would require knowing ahead if we are going to
        // have decoration taking horizontal spaces (typically a vertical scrollbar).
        if ((flags & ImGuiTableFlags_ScrollX) && inner_width > 0.0f)
            override_content_size.x = inner_width;

        if (override_content_size.x != FLT_MAX || override_content_size.y != FLT_MAX)
            SetNextWindowContentSize(ImVec2(override_content_size.x != FLT_MAX ? override_content_size.x : 0.0f, override_content_size.y != FLT_MAX ? override_content_size.y : 0.0f));

        // Create scrolling region (without border and zero window padding)
        ImGuiWindowFlags child_flags = (flags & ImGuiTableFlags_ScrollX) ? ImGuiWindowFlags_HorizontalScrollbar : ImGuiWindowFlags_None;
        BeginChildEx(name, instance_id, table->OuterRect.GetSize(), false, child_flags);
        table->InnerWindow = g.CurrentWindow;
        table->WorkRect = table->InnerWindow->WorkRect;
        table->OuterRect = table->InnerWindow->Rect();
        IM_ASSERT(table->InnerWindow->WindowPadding.x == 0.0f && table->InnerWindow->WindowPadding.y == 0.0f && table->InnerWindow->WindowBorderSize == 0.0f);
    }

    // Push a standardized ID for both child-using and not-child-using tables
    PushOverrideID(instance_id);

    // Backup a copy of host window members we will modify
    ImGuiWindow* inner_window = table->InnerWindow;
    table->HostIndentX = inner_window->DC.Indent.x;
    table->HostClipRect = inner_window->ClipRect;
    table->HostSkipItems = inner_window->SkipItems;
    table->HostBackupWorkRect = inner_window->WorkRect;
    table->HostBackupParentWorkRect = inner_window->ParentWorkRect;
    table->HostBackupColumnsOffset = outer_window->DC.ColumnsOffset;
    table->HostBackupCursorMaxPos = inner_window->DC.CursorMaxPos;
    table->HostBackupItemWidth = outer_window->DC.ItemWidth;
    table->HostBackupItemWidthStackSize = outer_window->DC.ItemWidthStack.Size;
    inner_window->ParentWorkRect = table->WorkRect;

    // Padding and Spacing
    // - None               ........Content..... Pad .....Content........
    // - PadOuter           | Pad ..Content..... Pad .....Content.. Pad |
    // - PadInner           ........Content.. Pad | Pad ..Content........
    // - PadOuter+PadInner  | Pad ..Content.. Pad | Pad ..Content.. Pad |
    const bool pad_outer_x = (flags & ImGuiTableFlags_NoPadOuterX) ? false : (flags & ImGuiTableFlags_PadOuterX) ? true : (flags & ImGuiTableFlags_BordersOuterV) != 0;
    const bool pad_inner_x = (flags & ImGuiTableFlags_NoPadInnerX) ? false : true;
    const float inner_spacing_for_border = (flags & ImGuiTableFlags_BordersInnerV) ? TABLE_BORDER_SIZE : 0.0f;
    const float inner_spacing_explicit = (pad_inner_x && (flags & ImGuiTableFlags_BordersInnerV) == 0) ? g.Style.CellPadding.x : 0.0f;
    const float inner_padding_explicit = (pad_inner_x && (flags & ImGuiTableFlags_BordersInnerV) != 0) ? g.Style.CellPadding.x : 0.0f;
    const float inner_spacing = inner_spacing_for_border + inner_spacing_explicit;
    table->CellSpacingX1 = ImCeil(inner_spacing * 0.5f);
    table->CellSpacingX2 = inner_spacing - table->CellSpacingX1;
    table->CellPaddingX = inner_padding_explicit;
    table->CellPaddingY = g.Style.CellPadding.y;

    const float outer_padding_for_border = (flags & ImGuiTableFlags_BordersOuterV) ? TABLE_BORDER_SIZE : 0.0f;
    const float outer_padding_explicit = pad_outer_x ? g.Style.CellPadding.x : 0.0f;
    table->OuterPaddingX = (outer_padding_for_border + outer_padding_explicit) - table->CellPaddingX;

    table->CurrentColumn = -1;
    table->CurrentRow = -1;
    table->RowBgColorCounter = 0;
    table->LastRowFlags = ImGuiTableRowFlags_None;
    table->InnerClipRect = (inner_window == outer_window) ? table->WorkRect : inner_window->ClipRect;
    table->InnerClipRect.ClipWith(table->WorkRect);     // We need this to honor inner_width
    table->InnerClipRect.ClipWithFull(table->HostClipRect);
    table->InnerClipRect.Max.y = (flags & ImGuiTableFlags_NoHostExtendY) ? ImMin(table->InnerClipRect.Max.y, inner_window->WorkRect.Max.y) : inner_window->ClipRect.Max.y;

    // Initial draw cmd starts with a BgClipRect that matches the one of its host, to facilitate merge draw commands by default.
    // This is because all our cell highlight are manually clipped with BgClipRect
    // Larger at first, if/after unfreezing will become same as tight
    table->BgClipRect = table->InnerClipRect;
    table->BgClipRectForDrawCmd = table->HostClipRect;
    IM_ASSERT(table->BgClipRect.Min.y <= table->BgClipRect.Max.y);

    table->RowPosY1 = table->RowPosY2 = table->WorkRect.Min.y; // This is needed somehow
    table->RowTextBaseline = 0.0f; // This will be cleared again by TableBeginRow()
    table->FreezeRowsRequest = table->FreezeRowsCount = 0; // This will be setup by TableSetupScrollFreeze(), if any
    table->FreezeColumnsRequest = table->FreezeColumnsCount = 0;
    table->IsUnfrozen = true;
    table->DeclColumnsCount = 0;
    table->RightMostEnabledColumn = -1;

    // Using opaque colors facilitate overlapping elements of the grid
    table->BorderColorStrong = GetColorU32(ImGuiCol_TableBorderStrong);
    table->BorderColorLight = GetColorU32(ImGuiCol_TableBorderLight);
    table->BorderX1 = table->InnerClipRect.Min.x;// +((table->Flags & ImGuiTableFlags_BordersOuter) ? 0.0f : -1.0f);
    table->BorderX2 = table->InnerClipRect.Max.x;// +((table->Flags & ImGuiTableFlags_BordersOuter) ? 0.0f : +1.0f);

    // Make table current
    const int table_idx = g.Tables.GetIndex(table);
    g.CurrentTableStack.push_back(ImGuiPtrOrIndex(table_idx));
    g.CurrentTable = table;
    outer_window->DC.CurrentTableIdx = table_idx;
    if (inner_window != outer_window) // So EndChild() within the inner window can restore the table properly.
        inner_window->DC.CurrentTableIdx = table_idx;

    if ((table_last_flags & ImGuiTableFlags_Reorderable) && (flags & ImGuiTableFlags_Reorderable) == 0)
        table->IsResetDisplayOrderRequest = true;

    // Mark as used
    if (table_idx >= g.TablesLastTimeActive.Size)
        g.TablesLastTimeActive.resize(table_idx + 1, -1.0f);
    g.TablesLastTimeActive[table_idx] = (float)g.Time;
    table->MemoryCompacted = false;

    // Setup memory buffer (clear data if columns count changed)
    const int stored_size = table->Columns.size();
    if (stored_size != 0 && stored_size != columns_count)
    {
        IM_FREE(table->RawData);
        table->RawData = NULL;
    }
    if (table->RawData == NULL)
    {
        TableBeginInitMemory(table, columns_count);
        if (table_is_new)
            table->IsInitializing = true;
        table->IsSortSpecsDirty = table->IsSettingsRequestLoad = true;
        table->SettingsOffset = -1;
    }

    // Load settings
    if (table->IsSettingsRequestLoad)
        TableLoadSettings(table);

    // Handle DPI/font resize
    // This is designed to facilitate DPI changes with the assumption that e.g. style.CellPadding has been scaled as well.
    // It will also react to changing fonts with mixed results. It doesn't need to be perfect but merely provide a decent transition.
    // FIXME-DPI: Provide consistent standards for reference size. Perhaps using g.CurrentDpiScale would be more self explanatory.
    // This is will lead us to non-rounded WidthRequest in columns, which should work but is a poorly tested path.
    const float new_ref_scale_unit = g.FontSize; // g.Font->GetCharAdvance('A') ?
    if (table->RefScale != 0.0f && table->RefScale != new_ref_scale_unit)
    {
        const float scale_factor = new_ref_scale_unit / table->RefScale;
        //IMGUI_DEBUG_LOG("[table] %08X RefScaleUnit %.3f -> %.3f, scaling width by %.3f\n", table->ID, table->RefScaleUnit, new_ref_scale_unit, scale_factor);
        for (int n = 0; n < columns_count; n++)
            table->Columns[n].WidthRequest = table->Columns[n].WidthRequest * scale_factor;
    }
    table->RefScale = new_ref_scale_unit;

    // Disable output until user calls TableNextRow() or TableNextColumn() leading to the TableUpdateLayout() call..
    // This is not strictly necessary but will reduce cases were "out of table" output will be misleading to the user.
    // Because we cannot safely assert in EndTable() when no rows have been created, this seems like our best option.
    inner_window->SkipItems = true;

    // Clear names
    // FIXME-TABLES: probably could be done differently...
    if (table->ColumnsNames.Buf.Size > 0)
    {
        table->ColumnsNames.Buf.resize(0);
        for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
        {
            ImGuiTableColumn* column = &table->Columns[column_n];
            column->NameOffset = -1;
        }
    }

    // Apply queued resizing/reordering/hiding requests
    TableBeginApplyRequests(table);

    return true;
}

// Apply queued resizing/reordering/hiding requests
void ImGui::TableBeginApplyRequests(ImGuiTable* table)
{
    // Handle resizing request
    // (We process this at the first TableBegin of the frame)
    // FIXME-TABLE: Preserve contents width _while resizing down_ until releasing.
    // FIXME-TABLE: Contains columns if our work area doesn't allow for scrolling.
    if (table->InstanceCurrent == 0)
    {
        if (table->ResizedColumn != -1 && table->ResizedColumnNextWidth != FLT_MAX)
            TableSetColumnWidth(table->ResizedColumn, table->ResizedColumnNextWidth);
        table->LastResizedColumn = table->ResizedColumn;
        table->ResizedColumnNextWidth = FLT_MAX;
        table->ResizedColumn = -1;

        // Process auto-fit for single stretch column, which is a special case
        // FIXME-TABLE: Would be nice to redistribute available stretch space accordingly to other weights, instead of giving it all to siblings.
        if (table->AutoFitSingleStretchColumn != -1)
        {
            table->Columns[table->AutoFitSingleStretchColumn].AutoFitQueue = 0x00;
            TableSetColumnWidth(table->AutoFitSingleStretchColumn, table->Columns[table->AutoFitSingleStretchColumn].WidthAuto);
            table->AutoFitSingleStretchColumn = -1;
        }
    }

    // Handle reordering request
    // Note: we don't clear ReorderColumn after handling the request.
    if (table->InstanceCurrent == 0)
    {
        if (table->HeldHeaderColumn == -1 && table->ReorderColumn != -1)
            table->ReorderColumn = -1;
        table->HeldHeaderColumn = -1;
        if (table->ReorderColumn != -1 && table->ReorderColumnDir != 0)
        {
            // We need to handle reordering across hidden columns.
            // In the configuration below, moving C to the right of E will lead to:
            //    ... C [D] E  --->  ... [D] E  C   (Column name/index)
            //    ... 2  3  4        ...  2  3  4   (Display order)
            const int reorder_dir = table->ReorderColumnDir;
            IM_ASSERT(reorder_dir == -1 || reorder_dir == +1);
            IM_ASSERT(table->Flags & ImGuiTableFlags_Reorderable);
            ImGuiTableColumn* src_column = &table->Columns[table->ReorderColumn];
            ImGuiTableColumn* dst_column = &table->Columns[(reorder_dir == -1) ? src_column->PrevEnabledColumn : src_column->NextEnabledColumn];
            IM_UNUSED(dst_column);
            const int src_order = src_column->DisplayOrder;
            const int dst_order = dst_column->DisplayOrder;
            src_column->DisplayOrder = (ImS8)dst_order;
            for (int order_n = src_order + reorder_dir; order_n != dst_order + reorder_dir; order_n += reorder_dir)
                table->Columns[table->DisplayOrderToIndex[order_n]].DisplayOrder -= (ImS8)reorder_dir;
            IM_ASSERT(dst_column->DisplayOrder == dst_order - reorder_dir);

            // Display order is stored in both columns->IndexDisplayOrder and table->DisplayOrder[],
            // rebuild the later from the former.
            for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
                table->DisplayOrderToIndex[table->Columns[column_n].DisplayOrder] = (ImS8)column_n;
            table->ReorderColumnDir = 0;
            table->IsSettingsDirty = true;
        }
    }

    // Handle display order reset request
    if (table->IsResetDisplayOrderRequest)
    {
        for (int n = 0; n < table->ColumnsCount; n++)
            table->DisplayOrderToIndex[n] = table->Columns[n].DisplayOrder = (ImS8)n;
        table->IsResetDisplayOrderRequest = false;
        table->IsSettingsDirty = true;
    }
}

// Adjust flags: default width mode + stretch columns are not allowed when auto extending
static ImGuiTableColumnFlags TableFixColumnFlags(ImGuiTable* table, ImGuiTableColumnFlags flags)
{
    // Sizing Policy
    if ((flags & ImGuiTableColumnFlags_WidthMask_) == 0)
    {
        // FIXME-TABLE: Inconsistent to promote columns to WidthAutoResize
        if (table->Flags & ImGuiTableFlags_ColumnsWidthFixed)
            flags |= ((table->Flags & ImGuiTableFlags_Resizable) && !(flags & ImGuiTableColumnFlags_NoResize)) ? ImGuiTableColumnFlags_WidthFixed : ImGuiTableColumnFlags_WidthAutoResize;
        else
            flags |= ImGuiTableColumnFlags_WidthStretch;
    }
    IM_ASSERT(ImIsPowerOfTwo(flags & ImGuiTableColumnFlags_WidthMask_)); // Check that only 1 of each set is used.
    if (flags & ImGuiTableColumnFlags_WidthAutoResize)
        flags |= ImGuiTableColumnFlags_NoResize;

    // Sorting
    if ((flags & ImGuiTableColumnFlags_NoSortAscending) && (flags & ImGuiTableColumnFlags_NoSortDescending))
        flags |= ImGuiTableColumnFlags_NoSort;

    // Alignment
    //if ((flags & ImGuiTableColumnFlags_AlignMask_) == 0)
    //    flags |= ImGuiTableColumnFlags_AlignCenter;
    //IM_ASSERT(ImIsPowerOfTwo(flags & ImGuiTableColumnFlags_AlignMask_)); // Check that only 1 of each set is used.

    return flags;
}

// Minimum column content width (without padding)
static float TableGetMinColumnWidth()
{
    ImGuiContext& g = *GImGui;
    //return g.Style.ColumnsMinSpacing; // FIXME-TABLE
    return g.Style.FramePadding.x * 1.0f;
}

// Layout columns for the frame
// Runs on the first call to TableNextRow(), to give a chance for TableSetupColumn() to be called first.
// FIXME-TABLE: Our width (and therefore our WorkRect) will be minimal in the first frame for WidthAutoResize
// columns, increase feedback side-effect with widgets relying on WorkRect.Max.x. Maybe provide a default distribution
// for WidthAutoResize columns?
void    ImGui::TableUpdateLayout(ImGuiTable* table)
{
    ImGuiContext& g = *GImGui;
    IM_ASSERT(table->IsLayoutLocked == false);

    table->HoveredColumnBody = -1;
    table->HoveredColumnBorder = -1;

    // Lock Enabled state and Order
    ImGuiTableColumn* last_visible_column = NULL;
    bool want_column_auto_fit = false;
    table->IsDefaultDisplayOrder = true;
    table->ColumnsEnabledCount = 0;
    for (int order_n = 0; order_n < table->ColumnsCount; order_n++)
    {
        const int column_n = table->DisplayOrderToIndex[order_n];
        if (column_n != order_n)
            table->IsDefaultDisplayOrder = false;
        ImGuiTableColumn* column = &table->Columns[column_n];
        if (!(table->Flags & ImGuiTableFlags_Hideable) || (column->Flags & ImGuiTableColumnFlags_NoHide))
            column->IsEnabledNextFrame = true;
        if (column->IsEnabled != column->IsEnabledNextFrame)
        {
            column->IsEnabled = column->IsEnabledNextFrame;
            table->IsSettingsDirty = true;
            if (!column->IsEnabled && column->SortOrder != -1)
                table->IsSortSpecsDirty = true;
        }
        if (column->SortOrder > 0 && !(table->Flags & ImGuiTableFlags_MultiSortable))
            table->IsSortSpecsDirty = true;
        if (column->AutoFitQueue != 0x00)
            want_column_auto_fit = true;

        ImU64 index_mask = (ImU64)1 << column_n;
        ImU64 display_order_mask = (ImU64)1 << column->DisplayOrder;
        if (column->IsEnabled)
        {
            column->PrevEnabledColumn = column->NextEnabledColumn = -1;
            if (last_visible_column)
            {
                last_visible_column->NextEnabledColumn = (ImS8)column_n;
                column->PrevEnabledColumn = (ImS8)table->Columns.index_from_ptr(last_visible_column);
            }
            column->IndexWithinEnabledSet = table->ColumnsEnabledCount;
            table->ColumnsEnabledCount++;
            table->EnabledMaskByIndex |= index_mask;
            table->EnabledMaskByDisplayOrder |= display_order_mask;
            last_visible_column = column;
        }
        else
        {
            column->IndexWithinEnabledSet = -1;
            table->EnabledMaskByIndex &= ~index_mask;
            table->EnabledMaskByDisplayOrder &= ~display_order_mask;
        }
        IM_ASSERT(column->IndexWithinEnabledSet <= column->DisplayOrder);
    }
    table->EnabledUnclippedMaskByIndex = table->EnabledMaskByIndex; // Columns will be masked out below when Clipped
    table->RightMostEnabledColumn = (ImS8)(last_visible_column ? table->Columns.index_from_ptr(last_visible_column) : -1);

    // Disable child window clipping while fitting columns. This is not strictly necessary but makes it possible to avoid
    // the column fitting to wait until the first visible frame of the child container (may or not be a good thing).
    if (want_column_auto_fit && table->OuterWindow != table->InnerWindow)
        table->InnerWindow->SkipItems = false;
    if (want_column_auto_fit)
        table->IsSettingsDirty = true;

    // Compute offset, clip rect for the frame
    // (can't make auto padding larger than what WorkRect knows about so right-alignment matches)
    const ImRect work_rect = table->WorkRect;
    const float min_column_width = TableGetMinColumnWidth();
    const float min_column_distance = min_column_width + table->CellPaddingX * 2.0f + table->CellSpacingX1 + table->CellSpacingX2;

    int count_fixed = 0;
    float sum_weights_stretched = 0.0f;     // Sum of all weights for weighted columns.
    float sum_width_fixed_requests = 0.0f;  // Sum of all width for fixed and auto-resize columns, excluding width contributed by Stretch columns.
    float max_width_auto = 0.0f;
    table->LeftMostStretchedColumnDisplayOrder = -1;
    for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
    {
        if (!(table->EnabledMaskByIndex & ((ImU64)1 << column_n)))
            continue;
        ImGuiTableColumn* column = &table->Columns[column_n];

        // Adjust flags: default width mode + weighted columns are not allowed when auto extending
        // FIXME-TABLE: Clarify why we need to do this again here and not just in TableSetupColumn()
        column->Flags = TableFixColumnFlags(table, column->FlagsIn);
        if ((column->Flags & ImGuiTableColumnFlags_IndentMask_) == 0)
            column->Flags |= (column_n == 0) ? ImGuiTableColumnFlags_IndentEnable : ImGuiTableColumnFlags_IndentDisable;

        // We have a unusual edge case where if the user doesn't call TableGetSortSpecs() but has sorting enabled
        // or varying sorting flags, we still want the sorting arrows to honor those flags.
        if (table->Flags & ImGuiTableFlags_Sortable)
            TableFixColumnSortDirection(column);

        // Calculate "ideal" column width for nothing to be clipped.
        // Combine width from regular rows + width from headers unless requested not to.
        const float content_width_body = (float)ImMax(column->ContentMaxXFrozen, column->ContentMaxXUnfrozen) - column->WorkMinX;
        const float content_width_headers = (float)column->ContentMaxXHeadersIdeal - column->WorkMinX;
        float width_auto = content_width_body;
        if (!(table->Flags & ImGuiTableFlags_NoHeadersWidth) && !(column->Flags & ImGuiTableColumnFlags_NoHeaderWidth))
            width_auto = ImMax(width_auto, content_width_headers);
        width_auto = ImMax(width_auto, min_column_width);

        // Non-resizable columns also submit their requested width
        if ((column->Flags & ImGuiTableColumnFlags_WidthFixed) && column->InitStretchWeightOrWidth > 0.0f)
            if (!(table->Flags & ImGuiTableFlags_Resizable) || !(column->Flags & ImGuiTableColumnFlags_NoResize))
                width_auto = ImMax(width_auto, column->InitStretchWeightOrWidth);

        column->WidthAuto = width_auto;

        if (column->Flags & (ImGuiTableColumnFlags_WidthFixed | ImGuiTableColumnFlags_WidthAutoResize))
        {
            // Process auto-fit for non-stretched columns
            // Latch initial size for fixed columns and update it constantly for auto-resizing column (unless clipped!)
            if ((column->AutoFitQueue != 0x00) || ((column->Flags & ImGuiTableColumnFlags_WidthAutoResize) && !column->IsClipped))
                column->WidthRequest = width_auto;

            // FIXME-TABLE: Increase minimum size during init frame to avoid biasing auto-fitting widgets
            // (e.g. TextWrapped) too much. Otherwise what tends to happen is that TextWrapped would output a very
            // large height (= first frame scrollbar display very off + clipper would skip lots of items).
            // This is merely making the side-effect less extreme, but doesn't properly fixes it.
            // FIXME: Move this to ->WidthGiven to avoid temporary lossyless?
            if (column->AutoFitQueue > 0x01 && table->IsInitializing)
                column->WidthRequest = ImMax(column->WidthRequest, min_column_width * 4.0f); // FIXME-TABLE: Another constant/scale?

            count_fixed += 1;
            sum_width_fixed_requests += column->WidthRequest;
        }
        else
        {
            IM_ASSERT(column->Flags & ImGuiTableColumnFlags_WidthStretch);
            const float default_weight = (column->InitStretchWeightOrWidth > 0.0f) ? column->InitStretchWeightOrWidth : 1.0f;
            if (column->AutoFitQueue != 0x00)
                column->StretchWeight = default_weight;
            sum_weights_stretched += column->StretchWeight;
            if (table->LeftMostStretchedColumnDisplayOrder == -1 || table->LeftMostStretchedColumnDisplayOrder > column->DisplayOrder)
                table->LeftMostStretchedColumnDisplayOrder = (ImS8)column->DisplayOrder;
        }
        max_width_auto = ImMax(max_width_auto, width_auto);
        sum_width_fixed_requests += table->CellPaddingX * 2.0f;
    }
    table->ColumnsEnabledFixedCount = (ImS8)count_fixed;

    // Apply "same widths"
    // - When all columns are fixed or columns are of mixed type: use the maximum auto width
    // - When all columns are stretch: use same weight
    const bool mixed_same_widths = (table->Flags & ImGuiTableFlags_SameWidths) && count_fixed > 0;
    if (table->Flags & ImGuiTableFlags_SameWidths)
    {
        for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
            if (table->EnabledMaskByIndex & ((ImU64)1 << column_n))
            {
                ImGuiTableColumn* column = &table->Columns[column_n];
                if (column->Flags & (ImGuiTableColumnFlags_WidthFixed | ImGuiTableColumnFlags_WidthAutoResize))
                {
                    sum_width_fixed_requests += max_width_auto - column->WidthRequest; // Update old sum
                    column->WidthRequest = max_width_auto;
                }
                else
                {
                    sum_weights_stretched += 1.0f - column->StretchWeight; // Update old sum
                    column->StretchWeight = 1.0f;
                    if (count_fixed > 0)
                        column->WidthRequest = max_width_auto;
                }
            }
    }

    // Layout
    const float width_spacings = (table->OuterPaddingX * 2.0f) + (table->CellSpacingX1 + table->CellSpacingX2) * (table->ColumnsEnabledCount - 1);
    const float width_avail = ((table->Flags & ImGuiTableFlags_ScrollX) && table->InnerWidth == 0.0f) ? table->InnerClipRect.GetWidth() : work_rect.GetWidth();
    const float width_avail_for_stretched_columns = mixed_same_widths ? 0.0f : width_avail - width_spacings - sum_width_fixed_requests;
    float width_remaining_for_stretched_columns = width_avail_for_stretched_columns;

    // Apply final width based on requested widths
    // Mark some columns as not resizable
    int count_resizable = 0;
    table->ColumnsTotalWidth = width_spacings;
    table->ColumnsAutoFitWidth = width_spacings;
    for (int order_n = 0; order_n < table->ColumnsCount; order_n++)
    {
        if (!(table->EnabledMaskByDisplayOrder & ((ImU64)1 << order_n)))
            continue;
        ImGuiTableColumn* column = &table->Columns[table->DisplayOrderToIndex[order_n]];

        // Allocate width for stretched/weighted columns
        if (column->Flags & ImGuiTableColumnFlags_WidthStretch)
        {
            // StretchWeight gets converted into WidthRequest
            if (!mixed_same_widths) 
            {
                float weight_ratio = column->StretchWeight / sum_weights_stretched;
                column->WidthRequest = IM_FLOOR(ImMax(width_avail_for_stretched_columns * weight_ratio, min_column_width) + 0.01f);
                width_remaining_for_stretched_columns -= column->WidthRequest;
            }

            // [Resize Rule 2] Resizing from right-side of a stretch column preceding a fixed column
            // needs to forward resizing to left-side of fixed column. We also need to copy the NoResize flag..
            if (column->NextEnabledColumn != -1)
                if (ImGuiTableColumn* next_column = &table->Columns[column->NextEnabledColumn])
                    if (next_column->Flags & ImGuiTableColumnFlags_WidthFixed)
                        column->Flags |= (next_column->Flags & ImGuiTableColumnFlags_NoDirectResize_);
        }

        // [Resize Rule 1] The right-most Visible column is not resizable if there is at least one Stretch column
        // (see comments in TableResizeColumn())
        if (column->NextEnabledColumn == -1 && table->LeftMostStretchedColumnDisplayOrder != -1)
            column->Flags |= ImGuiTableColumnFlags_NoDirectResize_;

        if (!(column->Flags & ImGuiTableColumnFlags_NoResize))
            count_resizable++;

        // Assign final width, record width in case we will need to shrink
        column->WidthGiven = ImFloor(ImMax(column->WidthRequest, min_column_width));
        table->ColumnsTotalWidth += column->WidthGiven + table->CellPaddingX * 2.0f;
        table->ColumnsAutoFitWidth += column->WidthAuto + table->CellPaddingX * 2.0f;
    }

    // Redistribute remainder width due to rounding (remainder width is < 1.0f * number of Stretch column).
    // Using right-to-left distribution (more likely to match resizing cursor), could be adjusted depending
    // on where the mouse cursor is and/or relative weights.
    if (width_remaining_for_stretched_columns >= 1.0f && !(table->Flags & ImGuiTableFlags_PreciseWidths))
        for (int order_n = table->ColumnsCount - 1; sum_weights_stretched > 0.0f && width_remaining_for_stretched_columns >= 1.0f && order_n >= 0; order_n--)
        {
            if (!(table->EnabledMaskByDisplayOrder & ((ImU64)1 << order_n)))
                continue;
            ImGuiTableColumn* column = &table->Columns[table->DisplayOrderToIndex[order_n]];
            if (!(column->Flags & ImGuiTableColumnFlags_WidthStretch))
                continue;
            column->WidthRequest += 1.0f;
            column->WidthGiven += 1.0f;
            width_remaining_for_stretched_columns -= 1.0f;
        }

    // Detect hovered column
    const ImRect mouse_hit_rect(table->OuterRect.Min.x, table->OuterRect.Min.y, table->OuterRect.Max.x, ImMax(table->OuterRect.Max.y, table->OuterRect.Min.y + table->LastOuterHeight));
    const bool is_hovering_table = ItemHoverable(mouse_hit_rect, 0);

    // Setup final position, offset and clipping rectangles
    int visible_n = 0;
    float offset_x = (table->FreezeColumnsCount > 0) ? table->OuterRect.Min.x : work_rect.Min.x;
    offset_x += table->OuterPaddingX;
    offset_x -= table->CellSpacingX1;
    ImRect host_clip_rect = table->InnerClipRect;
    //host_clip_rect.Max.x += table->CellPaddingX + table->CellSpacingX2;
    for (int order_n = 0; order_n < table->ColumnsCount; order_n++)
    {
        const int column_n = table->DisplayOrderToIndex[order_n];
        ImGuiTableColumn* column = &table->Columns[column_n];

        column->NavLayerCurrent = (ImS8)((table->FreezeRowsCount > 0 || column_n < table->FreezeColumnsCount) ? ImGuiNavLayer_Menu : ImGuiNavLayer_Main);

        if (table->FreezeColumnsCount > 0 && table->FreezeColumnsCount == visible_n)
            offset_x += work_rect.Min.x - table->OuterRect.Min.x;

        if ((table->EnabledMaskByDisplayOrder & ((ImU64)1 << order_n)) == 0)
        {
            // Hidden column: clear a few fields and we are done with it for the remainder of the function.
            // We set a zero-width clip rect but set Min.y/Max.y properly to not interfere with the clipper.
            column->MinX = column->MaxX = column->WorkMinX = column->ClipRect.Min.x = column->ClipRect.Max.x = offset_x;
            column->WidthGiven = 0.0f;
            column->ClipRect.Min.y = work_rect.Min.y;
            column->ClipRect.Max.y = FLT_MAX;
            column->ClipRect.ClipWithFull(host_clip_rect);
            column->IsClipped = column->IsSkipItems = true;
            column->ItemWidth = 1.0f;
            continue;
        }

        // Maximum width
        float max_width = FLT_MAX;
        if (table->Flags & ImGuiTableFlags_ScrollX)
        {
            // Frozen columns can't reach beyond visible width else scrolling will naturally break.
            if (order_n < table->FreezeColumnsRequest)
            {
                max_width = (table->InnerClipRect.Max.x - (table->FreezeColumnsRequest - order_n) * min_column_distance) - offset_x;
                max_width = max_width - table->OuterPaddingX - table->CellPaddingX - table->CellSpacingX2;
            }
        }
        else if ((table->Flags & ImGuiTableFlags_NoKeepColumnsVisible) == 0)
        {
            // If horizontal scrolling if disabled, we apply a final lossless shrinking of columns in order to make
            // sure they are all visible. Because of this we also know that all of the columns will always fit in
            // table->WorkRect and therefore in table->InnerRect (because ScrollX is off)
            // FIXME-TABLE: This is solved incorrectly but also quite a difficult problem to fix as we also want ClipRect width to match.
            // See "table_width_distrib" and "table_width_keep_visible" tests
            max_width = table->WorkRect.Max.x - (table->ColumnsEnabledCount - column->IndexWithinEnabledSet - 1) * min_column_distance - offset_x;
            //max_width -= table->CellSpacingX1;
            max_width -= table->CellSpacingX2;
            max_width -= table->CellPaddingX * 2.0f;
            max_width -= table->OuterPaddingX;
        }
        column->WidthGiven = ImMin(column->WidthGiven, max_width);

        // Minimum width
        column->WidthGiven = ImMax(column->WidthGiven, ImMin(column->WidthRequest, min_column_width));

        // Lock all our positions
        // - ClipRect.Min.x: Because merging draw commands doesn't compare min boundaries, we make ClipRect.Min.x match left bounds to be consistent regardless of merging.
        // - ClipRect.Max.x: using WorkMaxX instead of MaxX (aka including padding) is detrimental to visibility in very-small column.
        // - FIXME-TABLE: We want equal width columns to have equal (ClipRect.Max.x - WorkMinX) width, which means ClipRect.max.x cannot stray off host_clip_rect.Max.x else right-most column may appear shorter.
        column->MinX = offset_x;
        column->MaxX = offset_x + column->WidthGiven + table->CellSpacingX1 + table->CellSpacingX2 + table->CellPaddingX * 2.0f;
        column->WorkMinX = column->MinX + table->CellPaddingX + table->CellSpacingX1;
        column->WorkMaxX = column->MaxX - table->CellPaddingX - table->CellSpacingX2; // Expected max
        column->ItemWidth = ImFloor(column->WidthGiven * 0.65f);
        column->ClipRect.Min.x = column->MinX;
        column->ClipRect.Min.y = work_rect.Min.y;
        column->ClipRect.Max.x = column->MaxX; // column->WorkMaxX;
        column->ClipRect.Max.y = FLT_MAX;
        column->ClipRect.ClipWithFull(host_clip_rect);

        column->IsClipped = (column->ClipRect.Max.x <= column->ClipRect.Min.x) && (column->AutoFitQueue & 1) == 0 && (column->CannotSkipItemsQueue & 1) == 0;
        if (column->IsClipped)
            table->EnabledUnclippedMaskByIndex &= ~((ImU64)1 << column_n); // Columns with the _WidthAutoResize sizing policy will never be updated then.

        column->IsSkipItems = !column->IsEnabled || table->HostSkipItems;

        // Detect hovered column
        if (is_hovering_table && g.IO.MousePos.x >= column->ClipRect.Min.x && g.IO.MousePos.x < column->ClipRect.Max.x)
            table->HoveredColumnBody = (ImS8)column_n;

        // Alignment
        // FIXME-TABLE: This align based on the whole column width, not per-cell, and therefore isn't useful in
        // many cases (to be able to honor this we might be able to store a log of cells width, per row, for
        // visible rows, but nav/programmatic scroll would have visible artifacts.)
        //if (column->Flags & ImGuiTableColumnFlags_AlignRight)
        //    column->WorkMinX = ImMax(column->WorkMinX, column->MaxX - column->ContentWidthRowsUnfrozen);
        //else if (column->Flags & ImGuiTableColumnFlags_AlignCenter)
        //    column->WorkMinX = ImLerp(column->WorkMinX, ImMax(column->StartX, column->MaxX - column->ContentWidthRowsUnfrozen), 0.5f);

        // Reset content width variables
        column->ContentMaxXFrozen = column->ContentMaxXUnfrozen = column->WorkMinX;
        column->ContentMaxXHeadersUsed = column->ContentMaxXHeadersIdeal = column->WorkMinX;

        // Don't decrement auto-fit counters until container window got a chance to submit its items
        if (table->HostSkipItems == false)
        {
            column->AutoFitQueue >>= 1;
            column->CannotSkipItemsQueue >>= 1;
        }

        if (visible_n < table->FreezeColumnsCount)
            host_clip_rect.Min.x = ImMax(host_clip_rect.Min.x, column->MaxX + TABLE_BORDER_SIZE);

        offset_x += column->WidthGiven + table->CellSpacingX1 + table->CellSpacingX2 + table->CellPaddingX * 2.0f;
        visible_n++;
    }

    // Detect/store when we are hovering the unused space after the right-most column (so e.g. context menus can react on it)
    if (is_hovering_table && table->HoveredColumnBody == -1)
    {
        float unused_x1 = table->WorkRect.Min.x;
        if (table->RightMostEnabledColumn != -1)
            unused_x1 = ImMax(unused_x1, table->Columns[table->RightMostEnabledColumn].ClipRect.Max.x);
        if (g.IO.MousePos.x >= unused_x1)
            table->HoveredColumnBody = (ImS8)table->ColumnsCount;
    }

    // Clear Resizable flag if none of our column are actually resizable (either via an explicit _NoResize flag,
    // either because of using _WidthAutoResize/_WidthStretch).
    // This will hide the resizing option from the context menu.
    if (count_resizable == 0 && (table->Flags & ImGuiTableFlags_Resizable))
        table->Flags &= ~ImGuiTableFlags_Resizable;

    // Allocate draw channels
    TableUpdateDrawChannels(table);

    // Borders
    if (table->Flags & ImGuiTableFlags_Resizable)
        TableUpdateBorders(table);

    // Reset fields after we used them in TableSetupResize()
    table->LastFirstRowHeight = 0.0f;
    table->IsLayoutLocked = true;
    table->IsUsingHeaders = false;

    // Context menu
    if (table->IsContextPopupOpen && table->InstanceCurrent == table->InstanceInteracted)
    {
        const ImGuiID context_menu_id = ImHashStr("##ContextMenu", 0, table->ID);
        if (BeginPopupEx(context_menu_id, ImGuiWindowFlags_AlwaysAutoResize | ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoSavedSettings))
        {
            TableDrawContextMenu(table);
            EndPopup();
        }
        else
        {
            table->IsContextPopupOpen = false;
        }
    }

    // Initial state
    ImGuiWindow* inner_window = table->InnerWindow;
    if (table->Flags & ImGuiTableFlags_NoClip)
        table->DrawSplitter.SetCurrentChannel(inner_window->DrawList, TABLE_DRAW_CHANNEL_UNCLIPPED);
    else
        inner_window->DrawList->PushClipRect(inner_window->ClipRect.Min, inner_window->ClipRect.Max, false);

    // Sanitize and build sort specs before we have a change to use them for display.
    // This path will only be exercised when sort specs are modified before header rows (e.g. init or visibility change)
    if (table->IsSortSpecsDirty && (table->Flags & ImGuiTableFlags_Sortable))
        TableSortSpecsBuild(table);
}

// Process interaction on resizing borders. Actual size change will be applied in EndTable()
// - Set table->HoveredColumnBorder with a short delay/timer to reduce feedback noise
// - Submit ahead of table contents and header, use ImGuiButtonFlags_AllowItemOverlap to prioritize widgets
//   overlapping the same area.
void    ImGui::TableUpdateBorders(ImGuiTable* table)
{
    ImGuiContext& g = *GImGui;
    IM_ASSERT(table->Flags & ImGuiTableFlags_Resizable);

    // At this point OuterRect height may be zero or under actual final height, so we rely on temporal coherency and
    // use the final height from last frame. Because this is only affecting _interaction_ with columns, it is not
    // really problematic (whereas the actual visual will be displayed in EndTable() and using the current frame height).
    // Actual columns highlight/render will be performed in EndTable() and not be affected.
    const float hit_half_width = TABLE_RESIZE_SEPARATOR_HALF_THICKNESS;
    const float hit_y1 = table->OuterRect.Min.y;
    const float hit_y2_body = ImMax(table->OuterRect.Max.y, hit_y1 + table->LastOuterHeight);
    const float hit_y2_head = hit_y1 + table->LastFirstRowHeight;

    for (int order_n = 0; order_n < table->ColumnsCount; order_n++)
    {
        if (!(table->EnabledMaskByDisplayOrder & ((ImU64)1 << order_n)))
            continue;

        const int column_n = table->DisplayOrderToIndex[order_n];
        ImGuiTableColumn* column = &table->Columns[column_n];
        if (column->Flags & (ImGuiTableColumnFlags_NoResize | ImGuiTableColumnFlags_NoDirectResize_))
            continue;

        // ImGuiTableFlags_NoBordersInBodyUntilResize will be honored in TableDrawBorders()
        const float border_y2_hit = (table->Flags & ImGuiTableFlags_NoBordersInBody) ? hit_y2_head : hit_y2_body;
        if ((table->Flags & ImGuiTableFlags_NoBordersInBody) && table->IsUsingHeaders == false)
            continue;

        ImGuiID column_id = TableGetColumnResizeID(table, column_n, table->InstanceCurrent);
        ImRect hit_rect(column->MaxX - hit_half_width, hit_y1, column->MaxX + hit_half_width, border_y2_hit);
        //GetForegroundDrawList()->AddRect(hit_rect.Min, hit_rect.Max, IM_COL32(255, 0, 0, 100));
        KeepAliveID(column_id);

        bool hovered = false, held = false;
        bool pressed = ButtonBehavior(hit_rect, column_id, &hovered, &held, ImGuiButtonFlags_FlattenChildren | ImGuiButtonFlags_AllowItemOverlap | ImGuiButtonFlags_PressedOnClick | ImGuiButtonFlags_PressedOnDoubleClick);
        if (pressed && IsMouseDoubleClicked(0))
        {
            TableSetColumnWidthAutoSingle(table, column_n);
            ClearActiveID();
            held = hovered = false;
        }
        if (held)
        {
            table->ResizedColumn = (ImS8)column_n;
            table->InstanceInteracted = table->InstanceCurrent;
        }
        if ((hovered && g.HoveredIdTimer > TABLE_RESIZE_SEPARATOR_FEEDBACK_TIMER) || held)
        {
            table->HoveredColumnBorder = (ImS8)column_n;
            SetMouseCursor(ImGuiMouseCursor_ResizeEW);
        }
    }
}

void    ImGui::EndTable()
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    IM_ASSERT(table != NULL && "Only call EndTable() if BeginTable() returns true!");

    // This assert would be very useful to catch a common error... unfortunately it would probably trigger in some
    // cases, and for consistency user may sometimes output empty tables (and still benefit from e.g. outer border)
    //IM_ASSERT(table->IsLayoutLocked && "Table unused: never called TableNextRow(), is that the intent?");

    // If the user never got to call TableNextRow() or TableNextColumn(), we call layout ourselves to ensure all our
    // code paths are consistent (instead of just hoping that TableBegin/TableEnd will work), get borders drawn, etc.
    if (!table->IsLayoutLocked)
        TableUpdateLayout(table);

    const ImGuiTableFlags flags = table->Flags;
    ImGuiWindow* inner_window = table->InnerWindow;
    ImGuiWindow* outer_window = table->OuterWindow;
    IM_ASSERT(inner_window == g.CurrentWindow);
    IM_ASSERT(outer_window == inner_window || outer_window == inner_window->ParentWindow);

    if (table->IsInsideRow)
        TableEndRow(table);

    // Context menu in columns body
    if (flags & ImGuiTableFlags_ContextMenuInBody)
        if (table->HoveredColumnBody != -1 && !ImGui::IsAnyItemHovered() && ImGui::IsMouseReleased(ImGuiMouseButton_Right))
            TableOpenContextMenu((int)table->HoveredColumnBody);

    // Finalize table height
    inner_window->DC.CursorMaxPos = table->HostBackupCursorMaxPos;
    if (inner_window != outer_window)
    {
        table->OuterRect.Max.y = ImMax(table->OuterRect.Max.y, inner_window->Pos.y + inner_window->Size.y);
        inner_window->DC.CursorMaxPos.y = table->RowPosY2;
    }
    else if (!(flags & ImGuiTableFlags_NoHostExtendY))
    {
        table->OuterRect.Max.y = ImMax(table->OuterRect.Max.y, inner_window->DC.CursorPos.y);
        inner_window->DC.CursorMaxPos.y = table->RowPosY2;
    }
    table->WorkRect.Max.y = ImMax(table->WorkRect.Max.y, table->OuterRect.Max.y);
    table->LastOuterHeight = table->OuterRect.GetHeight();

    if (!(flags & ImGuiTableFlags_NoClip))
        inner_window->DrawList->PopClipRect();
    inner_window->ClipRect = inner_window->DrawList->_ClipRectStack.back();

    // Draw borders
    if ((flags & ImGuiTableFlags_Borders) != 0)
        TableDrawBorders(table);
    table->DrawSplitter.SetCurrentChannel(inner_window->DrawList, 0);

    // Store content width reference for each column (before attempting to merge draw calls)
    const float backup_outer_cursor_pos_x = outer_window->DC.CursorPos.x;
    const float backup_outer_max_pos_x = outer_window->DC.CursorMaxPos.x;
    const float backup_inner_max_pos_x = inner_window->DC.CursorMaxPos.x;
    float max_pos_x = backup_inner_max_pos_x;
    if (table->RightMostEnabledColumn != -1)
        max_pos_x = ImMax(max_pos_x, table->Columns[table->RightMostEnabledColumn].MaxX);

#if 0
    // Strip out dummy channel draw calls
    // We have no way to prevent user submitting direct ImDrawList calls into a hidden column (but ImGui:: calls will be clipped out)
    // (The problem with this approach is we are effectively making it harder for users watching metrics to spot wasted vertices)
    if (table->DummyDrawChannel != (ImU8)-1)
    {
        ImDrawChannel* dummy_channel = &table->DrawSplitter._Channels[table->DummyDrawChannel];
        dummy_channel->_CmdBuffer.resize(0);
        dummy_channel->_IdxBuffer.resize(0);
    }
#endif

    // Flatten channels and merge draw calls
    if ((table->Flags & ImGuiTableFlags_NoClip) == 0)
        TableReorderDrawChannelsForMerge(table);
    table->DrawSplitter.Merge(inner_window->DrawList);

    if (!(table->Flags & ImGuiTableFlags_ScrollX) && inner_window != outer_window)
    {
        inner_window->Scroll.x = 0.0f;
    }
    else if (table->LastResizedColumn != -1 && table->ResizedColumn == -1 && inner_window->ScrollbarX && table->InstanceInteracted == table->InstanceCurrent)
    {
        // When releasing a column being resized, scroll to keep the resulting column in sight
        const float neighbor_width_to_keep_visible = TableGetMinColumnWidth() + table->CellPaddingX * 2.0f;
        ImGuiTableColumn* column = &table->Columns[table->LastResizedColumn];
        if (column->MaxX < table->InnerClipRect.Min.x)
            SetScrollFromPosX(inner_window, column->MaxX - inner_window->Pos.x - neighbor_width_to_keep_visible, 1.0f);
        else if (column->MaxX > table->InnerClipRect.Max.x)
            SetScrollFromPosX(inner_window, column->MaxX - inner_window->Pos.x + neighbor_width_to_keep_visible, 1.0f);
    }

    // Apply resizing/dragging at the end of the frame
    if (table->ResizedColumn != -1 && table->InstanceCurrent == table->InstanceInteracted)
    {
        ImGuiTableColumn* column = &table->Columns[table->ResizedColumn];
        const float new_x2 = (g.IO.MousePos.x - g.ActiveIdClickOffset.x + TABLE_RESIZE_SEPARATOR_HALF_THICKNESS);
        const float new_width = ImFloor(new_x2 - column->MinX - table->CellSpacingX1 - table->CellPaddingX * 2.0f);
        table->ResizedColumnNextWidth = new_width;
    }

    // Layout in outer window
    IM_ASSERT_USER_ERROR(inner_window->IDStack.back() == table->ID + table->InstanceCurrent, "Mismatching PushID/PopID!");
    IM_ASSERT_USER_ERROR(outer_window->DC.ItemWidthStack.Size >= table->HostBackupItemWidthStackSize, "Too many PopItemWidth!");
    PopID();
    inner_window->WorkRect = table->HostBackupWorkRect;
    inner_window->ParentWorkRect = table->HostBackupParentWorkRect;
    inner_window->SkipItems = table->HostSkipItems;
    outer_window->DC.CursorPos = table->OuterRect.Min;
    outer_window->DC.ItemWidth = table->HostBackupItemWidth;
    outer_window->DC.ItemWidthStack.Size = table->HostBackupItemWidthStackSize;
    outer_window->DC.ColumnsOffset = table->HostBackupColumnsOffset;
    if (inner_window != outer_window)
    {
        EndChild();
    }
    else
    {
        ImVec2 item_size = table->OuterRect.GetSize();
        item_size.x = table->ColumnsTotalWidth;
        ItemSize(item_size);
    }

    // Override EndChild/ItemSize max extent with our own to enable auto-resize on the X axis when possible
    // FIXME-TABLE: This can be improved (e.g. for Fixed columns we don't want to auto AutoFitWidth? or propagate window auto-fit to table?)
    if (table->Flags & ImGuiTableFlags_ScrollX)
    {
        inner_window->DC.CursorMaxPos.x = max_pos_x; // Set contents width for scrolling
        outer_window->DC.CursorMaxPos.x = ImMax(backup_outer_max_pos_x, backup_outer_cursor_pos_x + table->ColumnsTotalWidth + inner_window->ScrollbarSizes.x); // For auto-fit
    }
    else
    {
        outer_window->DC.CursorMaxPos.x = ImMax(backup_outer_max_pos_x, table->WorkRect.Min.x + table->ColumnsAutoFitWidth); // For auto-fit
    }

    // Save settings
    if (table->IsSettingsDirty)
        TableSaveSettings(table);

    // Clear or restore current table, if any
    IM_ASSERT(g.CurrentWindow == outer_window && g.CurrentTable == table);
    g.CurrentTableStack.pop_back();
    g.CurrentTable = g.CurrentTableStack.Size ? g.Tables.GetByIndex(g.CurrentTableStack.back().Index) : NULL;
    outer_window->DC.CurrentTableIdx = g.CurrentTable ? g.Tables.GetIndex(g.CurrentTable) : -1;
}

// FIXME-TABLE: This is a mess, need to redesign how we render borders.
void ImGui::TableDrawBorders(ImGuiTable* table)
{
    ImGuiWindow* inner_window = table->InnerWindow;
    ImGuiWindow* outer_window = table->OuterWindow;
    table->DrawSplitter.SetCurrentChannel(inner_window->DrawList, TABLE_DRAW_CHANNEL_BG0);
    if (inner_window->Hidden || !table->HostClipRect.Overlaps(table->InnerClipRect))
        return;
    ImDrawList* inner_drawlist = inner_window->DrawList;
    ImDrawList* outer_drawlist = outer_window->DrawList;

    // Draw inner border and resizing feedback
    const float border_size = TABLE_BORDER_SIZE;
    const float draw_y1 = table->OuterRect.Min.y;
    const float draw_y2_body = table->OuterRect.Max.y;
    const float draw_y2_head = table->IsUsingHeaders ? ((table->FreezeRowsCount >= 1 ? table->OuterRect.Min.y : table->WorkRect.Min.y) + table->LastFirstRowHeight) : draw_y1;

    if (table->Flags & ImGuiTableFlags_BordersInnerV)
    {
        for (int order_n = 0; order_n < table->ColumnsCount; order_n++)
        {
            if (!(table->EnabledMaskByDisplayOrder & ((ImU64)1 << order_n)))
                continue;

            const int column_n = table->DisplayOrderToIndex[order_n];
            ImGuiTableColumn* column = &table->Columns[column_n];
            const bool is_hovered = (table->HoveredColumnBorder == column_n);
            const bool is_resized = (table->ResizedColumn == column_n) && (table->InstanceInteracted == table->InstanceCurrent);
            const bool is_resizable = (column->Flags & (ImGuiTableColumnFlags_NoResize | ImGuiTableColumnFlags_NoDirectResize_)) == 0;

            if (column->MaxX > table->InnerClipRect.Max.x && !is_resized)// && is_hovered)
                continue;
            if (column->NextEnabledColumn == -1 && !is_resizable)
                continue;
            if (column->MaxX <= column->ClipRect.Min.x) // FIXME-TABLE FIXME-STYLE: Assume BorderSize==1, this is problematic if we want to increase the border size..
                continue;

            // Draw in outer window so right-most column won't be clipped
            // Always draw full height border when being resized/hovered, or on the delimitation of frozen column scrolling.
            ImU32 col;
            float draw_y2;
            if (is_hovered || is_resized || (table->FreezeColumnsCount != -1 && table->FreezeColumnsCount == order_n + 1))
            {
                draw_y2 = draw_y2_body;
                col = is_resized ? GetColorU32(ImGuiCol_SeparatorActive) : is_hovered ? GetColorU32(ImGuiCol_SeparatorHovered) : table->BorderColorStrong;
            }
            else
            {
                draw_y2 = (table->Flags & (ImGuiTableFlags_NoBordersInBody | ImGuiTableFlags_NoBordersInBodyUntilResize)) ? draw_y2_head : draw_y2_body;
                col = (table->Flags & (ImGuiTableFlags_NoBordersInBody | ImGuiTableFlags_NoBordersInBodyUntilResize)) ? table->BorderColorStrong : table->BorderColorLight;
            }

            if (draw_y2 > draw_y1)
                inner_drawlist->AddLine(ImVec2(column->MaxX, draw_y1), ImVec2(column->MaxX, draw_y2), col, border_size);
        }
    }

    // Draw outer border
    // FIXME-TABLE: could use AddRect or explicit VLine/HLine helper?
    if (table->Flags & ImGuiTableFlags_BordersOuter)
    {
        // Display outer border offset by 1 which is a simple way to display it without adding an extra draw call
        // (Without the offset, in outer_window it would be rendered behind cells, because child windows are above their
        // parent. In inner_window, it won't reach out over scrollbars. Another weird solution would be to display part
        // of it in inner window, and the part that's over scrollbars in the outer window..)
        // Either solution currently won't allow us to use a larger border size: the border would clipped.
        ImRect outer_border = table->OuterRect;
        const ImU32 outer_col = table->BorderColorStrong;
        if (inner_window != outer_window) // FIXME-TABLE
            outer_border.Expand(1.0f);
        if ((table->Flags & ImGuiTableFlags_BordersOuter) == ImGuiTableFlags_BordersOuter)
        {
            outer_drawlist->AddRect(outer_border.Min, outer_border.Max, outer_col, 0.0f, ~0, border_size);
        }
        else if (table->Flags & ImGuiTableFlags_BordersOuterV)
        {
            outer_drawlist->AddLine(outer_border.Min, ImVec2(outer_border.Min.x, outer_border.Max.y), outer_col, border_size);
            outer_drawlist->AddLine(ImVec2(outer_border.Max.x, outer_border.Min.y), outer_border.Max, outer_col, border_size);
        }
        else if (table->Flags & ImGuiTableFlags_BordersOuterH)
        {
            outer_drawlist->AddLine(outer_border.Min, ImVec2(outer_border.Max.x, outer_border.Min.y), outer_col, border_size);
            outer_drawlist->AddLine(ImVec2(outer_border.Min.x, outer_border.Max.y), outer_border.Max, outer_col, border_size);
        }
    }
    if ((table->Flags & ImGuiTableFlags_BordersInnerH) && table->RowPosY2 < table->OuterRect.Max.y)
    {
        // Draw bottom-most row border
        const float border_y = table->RowPosY2;
        if (border_y >= table->BgClipRect.Min.y && border_y < table->BgClipRect.Max.y)
            inner_drawlist->AddLine(ImVec2(table->BorderX1, border_y), ImVec2(table->BorderX2, border_y), table->BorderColorLight, border_size);
    }
}

static void TableUpdateColumnsWeightFromWidth(ImGuiTable* table)
{
    IM_ASSERT(table->LeftMostStretchedColumnDisplayOrder != -1);

    // Measure existing quantity
    float visible_weight = 0.0f;
    float visible_width = 0.0f;
    for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
    {
        ImGuiTableColumn* column = &table->Columns[column_n];
        if (!column->IsEnabled || !(column->Flags & ImGuiTableColumnFlags_WidthStretch))
            continue;
        visible_weight += column->StretchWeight;
        visible_width += column->WidthRequest;
    }
    IM_ASSERT(visible_weight > 0.0f && visible_width > 0.0f);

    // Apply new weights
    for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
    {
        ImGuiTableColumn* column = &table->Columns[column_n];
        if (!column->IsEnabled || !(column->Flags & ImGuiTableColumnFlags_WidthStretch))
            continue;
        column->StretchWeight = ((column->WidthRequest + 0.0f) / visible_width) * visible_weight;
    }
}

// 'width' = inner column width, without padding
void ImGui::TableSetColumnWidth(int column_n, float width)
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    IM_ASSERT(table != NULL && table->IsLayoutLocked == false);
    IM_ASSERT(column_n >= 0 && column_n < table->ColumnsCount);
    ImGuiTableColumn* column_0 = &table->Columns[column_n];
    float column_0_width = width;

    // Constraints
    const float min_width = TableGetMinColumnWidth();
    float max_width_0 = FLT_MAX;
    if (!(table->Flags & ImGuiTableFlags_ScrollX))
        max_width_0 = (table->WorkRect.Max.x - column_0->MinX) - (table->ColumnsEnabledCount - (column_0->IndexWithinEnabledSet + 1)) * min_width;
    column_0_width = ImClamp(column_0_width, min_width, max_width_0);

    // Compare both requested and actual given width to avoid overwriting requested width when column is stuck (minimum size, bounded)
    if (column_0->WidthGiven == column_0_width || column_0->WidthRequest == column_0_width)
        return;

    ImGuiTableColumn* column_1 = (column_0->NextEnabledColumn != -1) ? &table->Columns[column_0->NextEnabledColumn] : NULL;

    // In this surprisingly not simple because of how we support mixing Fixed and Stretch columns.
    // When forwarding resize from Wn| to Fn+1| we need to be considerate of the _NoResize flag on Fn+1.
    // FIXME-TABLE: Find a way to rewrite all of this so interactions feel more consistent for the user.
    // Scenarios:
    // - F1 F2 F3  resize from F1| or F2|   --> ok: alter ->WidthRequested of Fixed column. Subsequent columns will be offset.
    // - F1 F2 F3  resize from F3|          --> ok: alter ->WidthRequested of Fixed column. If active, ScrollX extent can be altered.
    // - F1 F2 W3  resize from F1| or F2|   --> ok: alter ->WidthRequested of Fixed column. If active, ScrollX extent can be altered, but it doesn't make much sense as the Stretch column will always be minimal size.
    // - F1 F2 W3  resize from W3|          --> ok: no-op (disabled by Resize Rule 1)
    // - W1 W2 W3  resize from W1| or W2|   --> FIXME
    // - W1 W2 W3  resize from W3|          --> ok: no-op (disabled by Resize Rule 1)
    // - W1 F2 F3  resize from F3|          --> ok: no-op (disabled by Resize Rule 1)
    // - W1 F2     resize from F2|          --> ok: no-op (disabled by Resize Rule 1)
    // - W1 W2 F3  resize from W1| or W2|   --> ok
    // - W1 F2 W3  resize from W1| or F2|   --> FIXME
    // - F1 W2 F3  resize from W2|          --> ok
    // - W1 F2 F3  resize from W1|          --> ok: equivalent to resizing |F2. F3 will not move. (forwarded by Resize Rule 2)
    // - W1 F2 F3  resize from F2|          --> FIXME should resize F2, F3 and not have effect on W1 (Stretch columns are _before_ the Fixed column).

    // Rules:
    // - [Resize Rule 1] Can't resize from right of right-most visible column if there is any Stretch column. Implemented in TableUpdateLayout().
    // - [Resize Rule 2] Resizing from right-side of a Stretch column before a fixed column forward sizing to left-side of fixed column.
    // - [Resize Rule 3] If we are are followed by a fixed column and we have a Stretch column before, we need to ensure that our left border won't move.
    table->IsSettingsDirty = true;
    if (column_0->Flags & ImGuiTableColumnFlags_WidthFixed)
    {
        // [Resize Rule 3] If we are are followed by a fixed column and we have a Stretch column before, we need to ensure
        // that our left border won't move, which we can do by making sure column_a/column_b resizes cancels each others.
        if (column_1 && (column_1->Flags & ImGuiTableColumnFlags_WidthFixed))
            if (table->LeftMostStretchedColumnDisplayOrder != -1 && table->LeftMostStretchedColumnDisplayOrder < column_0->DisplayOrder)
            {
                // (old_a + old_b == new_a + new_b) --> (new_a == old_a + old_b - new_b)
                float column_1_width = ImMax(column_1->WidthRequest - (column_0_width - column_0->WidthRequest), min_width);
                column_0_width = column_0->WidthRequest + column_1->WidthRequest - column_1_width;
                column_1->WidthRequest = column_1_width;
            }

        // Apply
        //IMGUI_DEBUG_LOG("TableSetColumnWidth(%d, %.1f->%.1f)\n", column_0_idx, column_0->WidthRequested, column_0_width);
        column_0->WidthRequest = column_0_width;
    }
    else if (column_0->Flags & ImGuiTableColumnFlags_WidthStretch)
    {
        // We can also use previous column if there's no next one
        if (column_1 == NULL)
            column_1 = (column_0->PrevEnabledColumn != -1) ? &table->Columns[column_0->PrevEnabledColumn] : NULL;
        if (column_1 == NULL)
            return;

        if (column_1->Flags & ImGuiTableColumnFlags_WidthFixed)
        {
            // [Resize Rule 2]
            float off = (column_0->WidthGiven - column_0_width);
            float column_1_width = column_1->WidthGiven + off;
            column_1->WidthRequest = ImMax(min_width, column_1_width);
        }
        else
        {
            // (old_a + old_b == new_a + new_b) --> (new_a == old_a + old_b - new_b)
            float column_1_width = ImMax(column_1->WidthRequest - (column_0_width - column_0->WidthRequest), min_width);
            column_0_width = column_0->WidthRequest + column_1->WidthRequest - column_1_width;
            column_1->WidthRequest = column_1_width;
            column_0->WidthRequest = column_0_width;
            TableUpdateColumnsWeightFromWidth(table);
        }
    }
}

// Allocate draw channels. Called by TableUpdateLayout()
// - We allocate them following storage order instead of display order so reordering columns won't needlessly
//   increase overall dormant memory cost.
// - We isolate headers draw commands in their own channels instead of just altering clip rects.
//   This is in order to facilitate merging of draw commands.
// - After crossing FreezeRowsCount, all columns see their current draw channel changed to a second set of channels.
// - We only use the dummy draw channel so we can push a null clipping rectangle into it without affecting other
//   channels, while simplifying per-row/per-cell overhead. It will be empty and discarded when merged.
// - We allocate 1 or 2 background draw channels. This is because we know PushTableBackground() is only used for
//   horizontal spanning. If we allowed vertical spanning we'd need one background draw channel per merge group (1-4).
// Draw channel allocation (before merging):
// - NoClip                       --> 2+D+1 channels: bg0 + bg1 + foreground (same clip rect == 1 draw call) (FIXME-TABLE: could merge bg1 and foreground?)
// - Clip                         --> 2+D+N channels
// - FreezeRows                   --> 2+D+N*2 (unless scrolling value is zero)
// - FreezeRows || FreezeColunns  --> 3+D+N*2 (unless scrolling value is zero)
// Where D is 1 if any column is clipped or hidden (dummy channel) otherwise 0.
void ImGui::TableUpdateDrawChannels(ImGuiTable* table)
{
    const int freeze_row_multiplier = (table->FreezeRowsCount > 0) ? 2 : 1;
    const int channels_for_row = (table->Flags & ImGuiTableFlags_NoClip) ? 1 : table->ColumnsEnabledCount;
    const int channels_for_bg = 1 + 1 * freeze_row_multiplier;
    const int channels_for_dummy = (table->ColumnsEnabledCount < table->ColumnsCount || table->EnabledUnclippedMaskByIndex != table->EnabledMaskByIndex) ? +1 : 0;
    const int channels_total = channels_for_bg + (channels_for_row * freeze_row_multiplier) + channels_for_dummy;
    table->DrawSplitter.Split(table->InnerWindow->DrawList, channels_total);
    table->DummyDrawChannel = (ImU8)((channels_for_dummy > 0) ? channels_total - 1 : -1);
    table->Bg1DrawChannelCurrent = TABLE_DRAW_CHANNEL_BG1_FROZEN;
    table->Bg1DrawChannelUnfrozen = (ImU8)((table->FreezeRowsCount > 0) ? 2 + channels_for_row : TABLE_DRAW_CHANNEL_BG1_FROZEN);

    int draw_channel_current = 2;
    for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
    {
        ImGuiTableColumn* column = &table->Columns[column_n];
        if (!column->IsClipped)
        {
            column->DrawChannelFrozen = (ImU8)(draw_channel_current);
            column->DrawChannelUnfrozen = (ImU8)(draw_channel_current + (table->FreezeRowsCount > 0 ? channels_for_row + 1 : 0));
            if (!(table->Flags & ImGuiTableFlags_NoClip))
                draw_channel_current++;
        }
        else
        {
            column->DrawChannelFrozen = column->DrawChannelUnfrozen = table->DummyDrawChannel;
        }
        column->DrawChannelCurrent = column->DrawChannelFrozen;
    }
}

// This function reorder draw channels based on matching clip rectangle, to facilitate merging them. Called by EndTable().
//
// Columns where the contents didn't stray off their local clip rectangle can be merged. To achieve
// this we merge their clip rect and make them contiguous in the channel list, so they can be merged
// by the call to DrawSplitter.Merge() following to the call to this function.
//
// We reorder draw commands by arranging them into a maximum of 4 distinct groups:
//
//   1 group:               2 groups:              2 groups:              4 groups:
//   [ 0. ] no freeze       [ 0. ] row freeze      [ 01 ] col freeze      [ 01 ] row+col freeze
//   [ .. ]  or no scroll   [ 2. ]  and v-scroll   [ .. ]  and h-scroll   [ 23 ]  and v+h-scroll
//
// Each column itself can use 1 channel (row freeze disabled) or 2 channels (row freeze enabled).
// When the contents of a column didn't stray off its limit, we move its channels into the corresponding group
// based on its position (within frozen rows/columns groups or not).
// At the end of the operation our 1-4 groups will each have a ImDrawCmd using the same ClipRect.
//
// This function assume that each column are pointing to a distinct draw channel,
// otherwise merge_group->ChannelsCount will not match set bit count of merge_group->ChannelsMask.
//
// Column channels will not be merged into one of the 1-4 groups in the following cases:
// - The contents stray off its clipping rectangle (we only compare the MaxX value, not the MinX value).
//   Direct ImDrawList calls won't be taken into account by default, if you use them make sure the ImGui:: bounds
//   matches, by e.g. calling SetCursorScreenPos().
// - The channel uses more than one draw command itself. We drop all our attempt at merging stuff here..
//   we could do better but it's going to be rare and probably not worth the hassle.
// Columns for which the draw channel(s) haven't been merged with other will use their own ImDrawCmd.
//
// This function is particularly tricky to understand.. take a breath.
void    ImGui::TableReorderDrawChannelsForMerge(ImGuiTable* table)
{
    ImGuiContext& g = *GImGui;
    ImDrawListSplitter* splitter = &table->DrawSplitter;
    const bool has_freeze_v = (table->FreezeRowsCount > 0);
    const bool has_freeze_h = (table->FreezeColumnsCount > 0);

    // Track which groups we are going to attempt to merge, and which channels goes into each group.
    struct MergeGroup
    {
        ImRect  ClipRect;
        int     ChannelsCount;
        ImBitArray<IMGUI_TABLE_MAX_DRAW_CHANNELS> ChannelsMask;
    };
    int merge_group_mask = 0x00;
    MergeGroup merge_groups[4];
    memset(merge_groups, 0, sizeof(merge_groups));

    // 1. Scan channels and take note of those which can be merged
    for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
    {
        if (!(table->EnabledUnclippedMaskByIndex & ((ImU64)1 << column_n)))
            continue;
        ImGuiTableColumn* column = &table->Columns[column_n];

        const int merge_group_sub_count = has_freeze_v ? 2 : 1;
        for (int merge_group_sub_n = 0; merge_group_sub_n < merge_group_sub_count; merge_group_sub_n++)
        {
            const int channel_no = (merge_group_sub_n == 0) ? column->DrawChannelFrozen : column->DrawChannelUnfrozen;

            // Don't attempt to merge if there are multiple draw calls within the column
            ImDrawChannel* src_channel = &splitter->_Channels[channel_no];
            if (src_channel->_CmdBuffer.Size > 0 && src_channel->_CmdBuffer.back().ElemCount == 0)
                src_channel->_CmdBuffer.pop_back();
            if (src_channel->_CmdBuffer.Size != 1)
                continue;

            // Find out the width of this merge group and check if it will fit in our column
            // (note that we assume that rendering didn't stray on the left direction. we should need a CursorMinPos to detect it)
            if (!(column->Flags & ImGuiTableColumnFlags_NoClip))
            {
                float content_max_x;
                if (!has_freeze_v)
                    content_max_x = ImMax(column->ContentMaxXUnfrozen, column->ContentMaxXHeadersUsed); // No row freeze
                else if (merge_group_sub_n == 0)
                    content_max_x = ImMax(column->ContentMaxXFrozen, column->ContentMaxXHeadersUsed);   // Row freeze: use width before freeze
                else
                    content_max_x = column->ContentMaxXUnfrozen;                                        // Row freeze: use width after freeze
                if (content_max_x > column->ClipRect.Max.x)
                    continue;
            }

            const int merge_group_n = (has_freeze_h && column_n < table->FreezeColumnsCount ? 0 : 1) + (has_freeze_v && merge_group_sub_n == 0 ? 0 : 2);
            IM_ASSERT(channel_no < IMGUI_TABLE_MAX_DRAW_CHANNELS);
            MergeGroup* merge_group = &merge_groups[merge_group_n];
            if (merge_group->ChannelsCount == 0)
                merge_group->ClipRect = ImRect(+FLT_MAX, +FLT_MAX, -FLT_MAX, -FLT_MAX);
            merge_group->ChannelsMask.SetBit(channel_no);
            merge_group->ChannelsCount++;
            merge_group->ClipRect.Add(src_channel->_CmdBuffer[0].ClipRect);
            merge_group_mask |= (1 << merge_group_n);
        }

        // Invalidate current draw channel
        // (we don't clear DrawChannelFrozen/DrawChannelUnfrozen solely to facilitate debugging/later inspection of data)
        column->DrawChannelCurrent = (ImU8)-1;
    }

    // [DEBUG] Display merge groups
#if 0
    if (g.IO.KeyShift)
        for (int merge_group_n = 0; merge_group_n < IM_ARRAYSIZE(merge_groups); merge_group_n++)
        {
            MergeGroup* merge_group = &merge_groups[merge_group_n];
            if (merge_group->ChannelsCount == 0)
                continue;
            char buf[32];
            ImFormatString(buf, 32, "MG%d:%d", merge_group_n, merge_group->ChannelsCount);
            ImVec2 text_pos = merge_group->ClipRect.Min + ImVec2(4, 4);
            ImVec2 text_size = CalcTextSize(buf, NULL);
            GetForegroundDrawList()->AddRectFilled(text_pos, text_pos + text_size, IM_COL32(0, 0, 0, 255));
            GetForegroundDrawList()->AddText(text_pos, IM_COL32(255, 255, 0, 255), buf, NULL);
            GetForegroundDrawList()->AddRect(merge_group->ClipRect.Min, merge_group->ClipRect.Max, IM_COL32(255, 255, 0, 255));
        }
#endif

    // 2. Rewrite channel list in our preferred order
    if (merge_group_mask != 0)
    {
        // We skip channel 0 (Bg0) and 1 (Bg1 frozen) from the shuffling since they won't move - see channels allocation in TableUpdateDrawChannels().
        const int LEADING_DRAW_CHANNELS = 2;
        g.DrawChannelsTempMergeBuffer.resize(splitter->_Count - LEADING_DRAW_CHANNELS); // Use shared temporary storage so the allocation gets amortized
        ImDrawChannel* dst_tmp = g.DrawChannelsTempMergeBuffer.Data;
        ImBitArray<IMGUI_TABLE_MAX_DRAW_CHANNELS> remaining_mask;                       // We need 132-bit of storage
        remaining_mask.ClearBits();
        remaining_mask.SetBitRange(LEADING_DRAW_CHANNELS, splitter->_Count - 1);
        remaining_mask.ClearBit(table->Bg1DrawChannelUnfrozen);
        IM_ASSERT(has_freeze_v == false || table->Bg1DrawChannelUnfrozen != TABLE_DRAW_CHANNEL_BG1_FROZEN);
        int remaining_count = splitter->_Count - (has_freeze_v ? LEADING_DRAW_CHANNELS + 1 : LEADING_DRAW_CHANNELS);
        //ImRect host_rect = (table->InnerWindow == table->OuterWindow) ? table->InnerClipRect : table->HostClipRect;
        ImRect host_rect = table->HostClipRect;
        for (int merge_group_n = 0; merge_group_n < IM_ARRAYSIZE(merge_groups); merge_group_n++)
        {
            if (int merge_channels_count = merge_groups[merge_group_n].ChannelsCount)
            {
                MergeGroup* merge_group = &merge_groups[merge_group_n];
                ImRect merge_clip_rect = merge_group->ClipRect;

                // Extend outer-most clip limits to match those of host, so draw calls can be merged even if
                // outer-most columns have some outer padding offsetting them from their parent ClipRect.
                // The principal cases this is dealing with are:
                // - On a same-window table (not scrolling = single group), all fitting columns ClipRect -> will extend and match host ClipRect -> will merge
                // - Columns can use padding and have left-most ClipRect.Min.x and right-most ClipRect.Max.x != from host ClipRect -> will extend and match host ClipRect -> will merge
                // FIXME-TABLE FIXME-WORKRECT: We are wasting a merge opportunity on tables without scrolling if column doesn't fit
                // within host clip rect, solely because of the half-padding difference between window->WorkRect and window->InnerClipRect.
                if ((merge_group_n & 1) == 0 || !has_freeze_h)
                    merge_clip_rect.Min.x = ImMin(merge_clip_rect.Min.x, host_rect.Min.x);
                if ((merge_group_n & 2) == 0 || !has_freeze_v)
                    merge_clip_rect.Min.y = ImMin(merge_clip_rect.Min.y, host_rect.Min.y);
                if ((merge_group_n & 1) != 0)
                    merge_clip_rect.Max.x = ImMax(merge_clip_rect.Max.x, host_rect.Max.x);
                if ((merge_group_n & 2) != 0 && (table->Flags & ImGuiTableFlags_NoHostExtendY) == 0)
                    merge_clip_rect.Max.y = ImMax(merge_clip_rect.Max.y, host_rect.Max.y);
#if 0
                GetOverlayDrawList()->AddRect(merge_group->ClipRect.Min, merge_group->ClipRect.Max, IM_COL32(255, 0, 0, 200), 0.0f, ~0, 1.0f);
                GetOverlayDrawList()->AddLine(merge_group->ClipRect.Min, merge_clip_rect.Min, IM_COL32(255, 100, 0, 200));
                GetOverlayDrawList()->AddLine(merge_group->ClipRect.Max, merge_clip_rect.Max, IM_COL32(255, 100, 0, 200));
#endif
                remaining_count -= merge_group->ChannelsCount;
                for (int n = 0; n < IM_ARRAYSIZE(remaining_mask.Storage); n++)
                    remaining_mask.Storage[n] &= ~merge_group->ChannelsMask.Storage[n];
                for (int n = 0; n < splitter->_Count && merge_channels_count != 0; n++)
                {
                    // Copy + overwrite new clip rect
                    if (!merge_group->ChannelsMask.TestBit(n))
                        continue;
                    merge_group->ChannelsMask.ClearBit(n);
                    merge_channels_count--;

                    ImDrawChannel* channel = &splitter->_Channels[n];
                    IM_ASSERT(channel->_CmdBuffer.Size == 1 && merge_clip_rect.Contains(ImRect(channel->_CmdBuffer[0].ClipRect)));
                    channel->_CmdBuffer[0].ClipRect = merge_clip_rect.ToVec4();
                    memcpy(dst_tmp++, channel, sizeof(ImDrawChannel));
                }
            }

            // Make sure Bg1DrawChannelUnfrozen appears in the middle of our groups (whereas Bg0 and Bg1 frozen are fixed to 0 and 1)
            if (merge_group_n == 1 && has_freeze_v)
                memcpy(dst_tmp++, &splitter->_Channels[table->Bg1DrawChannelUnfrozen], sizeof(ImDrawChannel));
        }

        // Append unmergeable channels that we didn't reorder at the end of the list
        for (int n = 0; n < splitter->_Count && remaining_count != 0; n++)
        {
            if (!remaining_mask.TestBit(n))
                continue;
            ImDrawChannel* channel = &splitter->_Channels[n];
            memcpy(dst_tmp++, channel, sizeof(ImDrawChannel));
            remaining_count--;
        }
        IM_ASSERT(dst_tmp == g.DrawChannelsTempMergeBuffer.Data + g.DrawChannelsTempMergeBuffer.Size);
        memcpy(splitter->_Channels.Data + LEADING_DRAW_CHANNELS, g.DrawChannelsTempMergeBuffer.Data, (splitter->_Count - LEADING_DRAW_CHANNELS) * sizeof(ImDrawChannel));
    }
}

// We use a default parameter of 'init_width_or_weight == -1',
// - with ImGuiTableColumnFlags_WidthFixed,    width  <= 0 --> init width == auto
// - with ImGuiTableColumnFlags_WidthFixed,    width  >  0 --> init width == manual
// - with ImGuiTableColumnFlags_WidthStretch,  weight <  0 --> init weight == 1.0f
// - with ImGuiTableColumnFlags_WidthStretch,  weight >= 0 --> init weight == custom
// Widths are specified _without_ CellPadding. So if you specify a width of 100.0f the column will be 100.0f+Padding*2.0f and you can fit a 100.0-wide item in it.
void    ImGui::TableSetupColumn(const char* label, ImGuiTableColumnFlags flags, float init_width_or_weight, ImGuiID user_id)
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    IM_ASSERT(table != NULL && "Need to call TableSetupColumn() after BeginTable()!");
    IM_ASSERT(table->IsLayoutLocked == false && "Need to call call TableSetupColumn() before first row!");
    IM_ASSERT(table->DeclColumnsCount >= 0 && table->DeclColumnsCount < table->ColumnsCount && "Called TableSetupColumn() too many times!");

    ImGuiTableColumn* column = &table->Columns[table->DeclColumnsCount];
    table->DeclColumnsCount++;

    // When passing a width automatically enforce WidthFixed policy
    // (vs TableFixColumnFlags would default to WidthAutoResize)
    // (we write to FlagsIn which is a little misleading, another solution would be to pass init_width_or_weight to TableFixColumnFlags)
    if ((flags & ImGuiTableColumnFlags_WidthMask_) == 0)
        if ((table->Flags & ImGuiTableFlags_ColumnsWidthFixed) && (init_width_or_weight > 0.0f))
            flags |= ImGuiTableColumnFlags_WidthFixed;

    column->UserID = user_id;
    column->FlagsIn = flags;
    column->Flags = TableFixColumnFlags(table, column->FlagsIn);
    flags = column->Flags;

    // Initialize defaults
    if (flags & ImGuiTableColumnFlags_WidthStretch)
        IM_ASSERT(init_width_or_weight != 0.0f && "Need to provide a valid weight!");
    column->InitStretchWeightOrWidth = init_width_or_weight;
    if (table->IsInitializing && column->WidthRequest < 0.0f && column->StretchWeight < 0.0f)
    {
        // Init width or weight
        if ((flags & ImGuiTableColumnFlags_WidthFixed) && init_width_or_weight > 0.0f)
            column->WidthRequest = init_width_or_weight;
        if (flags & ImGuiTableColumnFlags_WidthStretch)
            column->StretchWeight = (init_width_or_weight > 0.0f) ? init_width_or_weight : 1.0f;

        // Disable auto-fit if an explicit fixed width has been specified
        if (init_width_or_weight > 0.0f)
            column->AutoFitQueue = 0x00;
    }
    if (table->IsInitializing)
    {
        // Init default visibility/sort state
        if ((flags & ImGuiTableColumnFlags_DefaultHide) && (table->SettingsLoadedFlags & ImGuiTableFlags_Hideable) == 0)
            column->IsEnabled = column->IsEnabledNextFrame = false;
        if (flags & ImGuiTableColumnFlags_DefaultSort && (table->SettingsLoadedFlags & ImGuiTableFlags_Sortable) == 0)
        {
            column->SortOrder = 0; // Multiple columns using _DefaultSort will be reordered when building the sort specs.
            column->SortDirection = (column->Flags & ImGuiTableColumnFlags_PreferSortDescending) ? (ImS8)ImGuiSortDirection_Descending : (ImU8)(ImGuiSortDirection_Ascending);
        }
    }

    // Store name (append with zero-terminator in contiguous buffer)
    IM_ASSERT(column->NameOffset == -1);
    if (label != NULL && label[0] != 0)
    {
        column->NameOffset = (ImS16)table->ColumnsNames.size();
        table->ColumnsNames.append(label, label + strlen(label) + 1);
    }
}

void ImGui::TableSetupScrollFreeze(int columns, int rows)
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    IM_ASSERT(table != NULL && "Need to call TableSetupColumn() after BeginTable()!");
    IM_ASSERT(table->IsLayoutLocked == false && "Need to call TableSetupColumn() before first row!");
    IM_ASSERT(columns >= 0 && columns < IMGUI_TABLE_MAX_COLUMNS);
    IM_ASSERT(rows >= 0 && rows < 128); // Arbitrary limit

    table->FreezeColumnsRequest = (table->Flags & ImGuiTableFlags_ScrollX) ? (ImS8)columns : 0;
    table->FreezeColumnsCount = (table->InnerWindow->Scroll.x != 0.0f) ? table->FreezeColumnsRequest : 0;
    table->FreezeRowsRequest = (table->Flags & ImGuiTableFlags_ScrollY) ? (ImS8)rows : 0;
    table->FreezeRowsCount = (table->InnerWindow->Scroll.y != 0.0f) ? table->FreezeRowsRequest : 0;
    table->IsUnfrozen = (table->FreezeRowsCount == 0); // Make sure this is set before TableUpdateLayout() so ImGuiListClipper can benefit from it.b
}

// Starts into the first cell of a new row
void    ImGui::TableNextRow(ImGuiTableRowFlags row_flags, float row_min_height)
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;

    if (!table->IsLayoutLocked)
        TableUpdateLayout(table);
    if (table->IsInsideRow)
        TableEndRow(table);

    table->LastRowFlags = table->RowFlags;
    table->RowFlags = row_flags;
    table->RowMinHeight = row_min_height;
    TableBeginRow(table);

    // We honor min_row_height requested by user, but cannot guarantee per-row maximum height,
    // because that would essentially require a unique clipping rectangle per-cell.
    table->RowPosY2 += table->CellPaddingY * 2.0f;
    table->RowPosY2 = ImMax(table->RowPosY2, table->RowPosY1 + row_min_height);

    // Disable output until user calls TableNextColumn()
    table->InnerWindow->SkipItems = true;
}

// [Internal] Called by TableNextRow()!
void    ImGui::TableBeginRow(ImGuiTable* table)
{
    ImGuiWindow* window = table->InnerWindow;
    IM_ASSERT(!table->IsInsideRow);

    // New row
    table->CurrentRow++;
    table->CurrentColumn = -1;
    table->RowBgColor[0] = table->RowBgColor[1] = IM_COL32_DISABLE;
    table->RowCellDataCurrent = -1;
    table->IsInsideRow = true;

    // Begin frozen rows
    float next_y1 = table->RowPosY2;
    if (table->CurrentRow == 0 && table->FreezeRowsCount > 0)
        next_y1 = window->DC.CursorPos.y = table->OuterRect.Min.y;

    table->RowPosY1 = table->RowPosY2 = next_y1;
    table->RowTextBaseline = 0.0f;
    table->RowIndentOffsetX = window->DC.Indent.x - table->HostIndentX; // Lock indent
    window->DC.PrevLineTextBaseOffset = 0.0f;
    window->DC.CursorMaxPos.y = next_y1;

    // Making the header BG color non-transparent will allow us to overlay it multiple times when handling smooth dragging.
    if (table->RowFlags & ImGuiTableRowFlags_Headers)
    {
        TableSetBgColor(ImGuiTableBgTarget_RowBg0, GetColorU32(ImGuiCol_TableHeaderBg));
        if (table->CurrentRow == 0)
            table->IsUsingHeaders = true;
    }
}

// [Internal] Called by TableNextRow()!
void    ImGui::TableEndRow(ImGuiTable* table)
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;
    IM_ASSERT(window == table->InnerWindow);
    IM_ASSERT(table->IsInsideRow);

    if (table->CurrentColumn != -1)
        TableEndCell(table);

    // Position cursor at the bottom of our row so it can be used for e.g. clipping calculation. However it is
    // likely that the next call to TableBeginCell() will reposition the cursor to take account of vertical padding.
    window->DC.CursorPos.y = table->RowPosY2;

    // Row background fill
    const float bg_y1 = table->RowPosY1;
    const float bg_y2 = table->RowPosY2;

    const bool unfreeze_rows_actual = (table->CurrentRow + 1 == table->FreezeRowsCount);
    const bool unfreeze_rows_request = (table->CurrentRow + 1 == table->FreezeRowsRequest);
    if (table->CurrentRow == 0)
        table->LastFirstRowHeight = bg_y2 - bg_y1;

    const bool is_visible = (bg_y2 >= table->InnerClipRect.Min.y && bg_y1 <= table->InnerClipRect.Max.y);
    if (is_visible)
    {
        // Decide of background color for the row
        ImU32 bg_col0 = 0;
        ImU32 bg_col1 = 0;
        if (table->RowBgColor[0] != IM_COL32_DISABLE)
            bg_col0 = table->RowBgColor[0];
        else if (table->Flags & ImGuiTableFlags_RowBg)
            bg_col0 = GetColorU32((table->RowBgColorCounter & 1) ? ImGuiCol_TableRowBgAlt : ImGuiCol_TableRowBg);
        if (table->RowBgColor[1] != IM_COL32_DISABLE)
            bg_col1 = table->RowBgColor[1];

        // Decide of top border color
        ImU32 border_col = 0;
        const float border_size = TABLE_BORDER_SIZE;
        if (table->CurrentRow > 0 || table->InnerWindow == table->OuterWindow)
            if (table->Flags & ImGuiTableFlags_BordersInnerH)
                border_col = (table->LastRowFlags & ImGuiTableRowFlags_Headers) ? table->BorderColorStrong : table->BorderColorLight;

        const bool draw_cell_bg_color = table->RowCellDataCurrent >= 0;
        const bool draw_strong_bottom_border = unfreeze_rows_actual;
        if ((bg_col0 | bg_col1 | border_col) != 0 || draw_strong_bottom_border || draw_cell_bg_color)
        {
            // In theory we could call SetWindowClipRectBeforeSetChannel() but since we know TableEndRow() is
            // always followed by a change of clipping rectangle we perform the smallest overwrite possible here.
            if ((table->Flags & ImGuiTableFlags_NoClip) == 0)
                window->DrawList->_CmdHeader.ClipRect = table->BgClipRectForDrawCmd.ToVec4();
            table->DrawSplitter.SetCurrentChannel(window->DrawList, TABLE_DRAW_CHANNEL_BG0);
        }

        // Draw row background
        // We soft/cpu clip this so all backgrounds and borders can share the same clipping rectangle
        if (bg_col0 || bg_col1)
        {
            ImRect row_rect(table->WorkRect.Min.x, bg_y1, table->WorkRect.Max.x, bg_y2);
            row_rect.ClipWith(table->BgClipRect);
            if (bg_col0 != 0 && row_rect.Min.y < row_rect.Max.y)
                window->DrawList->AddRectFilled(row_rect.Min, row_rect.Max, bg_col0);
            if (bg_col1 != 0 && row_rect.Min.y < row_rect.Max.y)
                window->DrawList->AddRectFilled(row_rect.Min, row_rect.Max, bg_col1);
        }

        // Draw cell background color
        if (draw_cell_bg_color)
        {
            ImGuiTableCellData* cell_data_end = &table->RowCellData[table->RowCellDataCurrent];
            for (ImGuiTableCellData* cell_data = &table->RowCellData[0]; cell_data <= cell_data_end; cell_data++)
            {
                const ImGuiTableColumn* column = &table->Columns[cell_data->Column];
                ImRect cell_bg_rect = TableGetCellBgRect(table, cell_data->Column);
                cell_bg_rect.ClipWith(table->BgClipRect);
                cell_bg_rect.Min.x = ImMax(cell_bg_rect.Min.x, column->ClipRect.Min.x);     // So that first column after frozen one gets clipped
                cell_bg_rect.Max.x = ImMin(cell_bg_rect.Max.x, column->MaxX);
                window->DrawList->AddRectFilled(cell_bg_rect.Min, cell_bg_rect.Max, cell_data->BgColor);
            }
        }

        // Draw top border
        if (border_col && bg_y1 >= table->BgClipRect.Min.y && bg_y1 < table->BgClipRect.Max.y)
            window->DrawList->AddLine(ImVec2(table->BorderX1, bg_y1), ImVec2(table->BorderX2, bg_y1), border_col, border_size);

        // Draw bottom border at the row unfreezing mark (always strong)
        if (draw_strong_bottom_border && bg_y2 >= table->BgClipRect.Min.y && bg_y2 < table->BgClipRect.Max.y)
            window->DrawList->AddLine(ImVec2(table->BorderX1, bg_y2), ImVec2(table->BorderX2, bg_y2), table->BorderColorStrong, border_size);
    }

    // End frozen rows (when we are past the last frozen row line, teleport cursor and alter clipping rectangle)
    // We need to do that in TableEndRow() instead of TableBeginRow() so the list clipper can mark end of row and
    // get the new cursor position.
    if (unfreeze_rows_request)
        for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
        {
            ImGuiTableColumn* column = &table->Columns[column_n];
            column->NavLayerCurrent = (ImS8)((column_n < table->FreezeColumnsCount) ? ImGuiNavLayer_Menu : ImGuiNavLayer_Main);
        }
    if (unfreeze_rows_actual)
    {
        IM_ASSERT(table->IsUnfrozen == false);
        table->IsUnfrozen = true;

        // BgClipRect starts as table->InnerClipRect, reduce it now and make BgClipRectForDrawCmd == BgClipRect
        float y0 = ImMax(table->RowPosY2 + 1, window->InnerClipRect.Min.y);
        table->BgClipRect.Min.y = table->BgClipRectForDrawCmd.Min.y = ImMin(y0, window->InnerClipRect.Max.y);
        table->BgClipRect.Max.y = table->BgClipRectForDrawCmd.Max.y = window->InnerClipRect.Max.y;
        table->Bg1DrawChannelCurrent = table->Bg1DrawChannelUnfrozen;
        IM_ASSERT(table->BgClipRectForDrawCmd.Min.y <= table->BgClipRectForDrawCmd.Max.y);

        float row_height = table->RowPosY2 - table->RowPosY1;
        table->RowPosY2 = window->DC.CursorPos.y = table->WorkRect.Min.y + table->RowPosY2 - table->OuterRect.Min.y;
        table->RowPosY1 = table->RowPosY2 - row_height;
        for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
        {
            ImGuiTableColumn* column = &table->Columns[column_n];
            column->DrawChannelCurrent = column->DrawChannelUnfrozen;
            column->ClipRect.Min.y = table->BgClipRectForDrawCmd.Min.y;
        }

        // Update cliprect ahead of TableBeginCell() so clipper can access to new ClipRect->Min.y
        SetWindowClipRectBeforeSetChannel(window, table->Columns[0].ClipRect);
        table->DrawSplitter.SetCurrentChannel(window->DrawList, table->Columns[0].DrawChannelCurrent);
    }

    if (!(table->RowFlags & ImGuiTableRowFlags_Headers))
        table->RowBgColorCounter++;
    table->IsInsideRow = false;
}

// [Internal] Called by TableNextColumn()!
// This is called very frequently, so we need to be mindful of unnecessary overhead.
// FIXME-TABLE FIXME-OPT: Could probably shortcut some things for non-active or clipped columns.
void    ImGui::TableBeginCell(ImGuiTable* table, int column_n)
{
    ImGuiTableColumn* column = &table->Columns[column_n];
    ImGuiWindow* window = table->InnerWindow;
    table->CurrentColumn = column_n;

    // Start position is roughly ~~ CellRect.Min + CellPadding + Indent
    float start_x = column->WorkMinX;
    if (column->Flags & ImGuiTableColumnFlags_IndentEnable)
        start_x += table->RowIndentOffsetX; // ~~ += window.DC.Indent.x - table->HostIndentX, except we locked it for the row.

    window->DC.CursorPos.x = start_x;
    window->DC.CursorPos.y = table->RowPosY1 + table->CellPaddingY;
    window->DC.CursorMaxPos.x = window->DC.CursorPos.x;
    window->DC.ColumnsOffset.x = start_x - window->Pos.x - window->DC.Indent.x; // FIXME-WORKRECT
    window->DC.CurrLineTextBaseOffset = table->RowTextBaseline;
    window->DC.LastItemId = 0;
    window->DC.NavLayerCurrent = (ImGuiNavLayer)column->NavLayerCurrent;

    window->WorkRect.Min.y = window->DC.CursorPos.y;
    window->WorkRect.Min.x = column->WorkMinX;
    window->WorkRect.Max.x = column->WorkMaxX;
    window->DC.ItemWidth = column->ItemWidth;

    // To allow ImGuiListClipper to function we propagate our row height
    if (!column->IsEnabled)
        window->DC.CursorPos.y = ImMax(window->DC.CursorPos.y, table->RowPosY2);

    window->SkipItems = column->IsSkipItems;
    if (table->Flags & ImGuiTableFlags_NoClip)
    {
        // FIXME: if we end up drawing all borders/bg in EndTable, could remove this and just assert that channel hasn't changed.
        table->DrawSplitter.SetCurrentChannel(window->DrawList, TABLE_DRAW_CHANNEL_UNCLIPPED);
        //IM_ASSERT(table->DrawSplitter._Current == TABLE_DRAW_CHANNEL_UNCLIPPED);
    }
    else
    {
        // FIXME-TABLE: Could avoid this if draw channel is dummy channel?
        SetWindowClipRectBeforeSetChannel(window, column->ClipRect);
        table->DrawSplitter.SetCurrentChannel(window->DrawList, column->DrawChannelCurrent);
    }
}

// [Internal] Called by TableNextRow()/TableNextColumn()!
void    ImGui::TableEndCell(ImGuiTable* table)
{
    ImGuiTableColumn* column = &table->Columns[table->CurrentColumn];
    ImGuiWindow* window = table->InnerWindow;

    // Report maximum position so we can infer content size per column.
    float* p_max_pos_x;
    if (table->RowFlags & ImGuiTableRowFlags_Headers)
        p_max_pos_x = &column->ContentMaxXHeadersUsed;  // Useful in case user submit contents in header row that is not a TableHeader() call
    else
        p_max_pos_x = table->IsUnfrozen ? &column->ContentMaxXUnfrozen : &column->ContentMaxXFrozen;
    *p_max_pos_x = ImMax(*p_max_pos_x, window->DC.CursorMaxPos.x);
    table->RowPosY2 = ImMax(table->RowPosY2, window->DC.CursorMaxPos.y + table->CellPaddingY);
    column->ItemWidth = window->DC.ItemWidth;

    // Propagate text baseline for the entire row
    // FIXME-TABLE: Here we propagate text baseline from the last line of the cell.. instead of the first one.
    table->RowTextBaseline = ImMax(table->RowTextBaseline, window->DC.PrevLineTextBaseOffset);
}

// Append into the next column/cell
bool    ImGui::TableNextColumn()
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    if (!table)
        return false;

    if (table->IsInsideRow && table->CurrentColumn + 1 < table->ColumnsCount)
    {
        if (table->CurrentColumn != -1)
            TableEndCell(table);
        TableBeginCell(table, table->CurrentColumn + 1);
    }
    else
    {
        TableNextRow();
        TableBeginCell(table, 0);
    }

    // FIXME-TABLE: it is likely to alter layout if user skips a columns contents based on clipping.
    int column_n = table->CurrentColumn;
    return (table->EnabledUnclippedMaskByIndex & ((ImU64)1 << column_n)) != 0;
}

bool    ImGui::TableSetColumnIndex(int column_n)
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    if (!table)
        return false;

    if (table->CurrentColumn != column_n)
    {
        if (table->CurrentColumn != -1)
            TableEndCell(table);
        IM_ASSERT(column_n >= 0 && table->ColumnsCount);
        TableBeginCell(table, column_n);
    }

    // FIXME-TABLE: it is likely to alter layout if user skips a columns contents based on clipping.
    return (table->EnabledUnclippedMaskByIndex & ((ImU64)1 << column_n)) != 0;
}

int ImGui::TableGetColumnCount()
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    return table ? table->ColumnsCount : 0;
}

const char*   ImGui::TableGetColumnName(int column_n)
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    if (!table)
        return NULL;
    if (column_n < 0)
        column_n = table->CurrentColumn;
    return TableGetColumnName(table, column_n);
}

bool    ImGui::TableGetColumnIsEnabled(int column_n)
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    if (!table)
        return false;
    if (column_n < 0)
        column_n = table->CurrentColumn;
    return (table->EnabledMaskByIndex & ((ImU64)1 << column_n)) == 0;
}

void ImGui::TableSetColumnIsEnabled(int column_n, bool hidden)
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    IM_ASSERT(table != NULL && table->IsLayoutLocked == false);
    if (column_n < 0)
        column_n = table->CurrentColumn;
    IM_ASSERT(column_n >= 0 && column_n < table->ColumnsCount);
    table->Columns[column_n].IsEnabledNextFrame = !hidden;
}

int     ImGui::TableGetColumnIndex()
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    if (!table)
        return 0;
    return table->CurrentColumn;
}

// Note: for row coloring we use ->RowBgColorCounter which is the same value without counting header rows
int     ImGui::TableGetRowIndex()
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    if (!table)
        return 0;
    return table->CurrentRow;
}

// Return the cell rectangle based on currently known height.
// - Important: we generally don't know our row height until the end of the row, so Max.y will be incorrect in many situations.
//   The only case where this is correct is if we provided a min_row_height to TableNextRow() and don't go below it.
// - Important: if ImGuiTableFlags_PadOuterX is set but ImGuiTableFlags_PadInnerX is not set, the outer-most left and right
//   columns report a small offset so their CellBgRect can extend up to the outer border.
ImRect  ImGui::TableGetCellBgRect(const ImGuiTable* table, int column_n)
{
    const ImGuiTableColumn* column = &table->Columns[column_n];
    float x1 = column->MinX;
    float x2 = column->MaxX;
    if (column->PrevEnabledColumn == -1)
        x1 -= table->CellSpacingX1;
    if (column->NextEnabledColumn == -1)
        x2 += table->CellSpacingX2;
    return ImRect(x1, table->RowPosY1, x2, table->RowPosY2);
}

const char* ImGui::TableGetColumnName(const ImGuiTable* table, int column_n)
{
    const ImGuiTableColumn* column = &table->Columns[column_n];
    if (column->NameOffset == -1)
        return "";
    return &table->ColumnsNames.Buf[column->NameOffset];
}

// Return the resizing ID for the right-side of the given column.
ImGuiID ImGui::TableGetColumnResizeID(const ImGuiTable* table, int column_n, int instance_no)
{
    IM_ASSERT(column_n < table->ColumnsCount);
    ImGuiID id = table->ID + 1 + (instance_no * table->ColumnsCount) + column_n;
    return id;
}

// Disable clipping then auto-fit, will take 2 frames
// (we don't take a shortcut for unclipped columns to reduce inconsistencies when e.g. resizing multiple columns)
void    ImGui::TableSetColumnWidthAutoSingle(ImGuiTable* table, int column_n)
{
    // Single auto width uses auto-fit
    ImGuiTableColumn* column = &table->Columns[column_n];
    if (!column->IsEnabled)
        return;
    column->CannotSkipItemsQueue = (1 << 0);
    column->AutoFitQueue = (1 << 1);
    if (column->Flags & ImGuiTableColumnFlags_WidthStretch)
        table->AutoFitSingleStretchColumn = (ImS8)column_n;
}

void    ImGui::TableSetColumnWidthAutoAll(ImGuiTable* table)
{
    for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
    {
        ImGuiTableColumn* column = &table->Columns[column_n];
        if (!column->IsEnabled)
            continue;
        column->CannotSkipItemsQueue = (1 << 0);
        column->AutoFitQueue = (1 << 1);
    }
}

void    ImGui::TablePushBackgroundChannel()
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;
    ImGuiTable* table = g.CurrentTable;

    // Optimization: avoid SetCurrentChannel() + PushClipRect()
    table->HostBackupClipRect = window->ClipRect;
    SetWindowClipRectBeforeSetChannel(window, table->BgClipRectForDrawCmd);
    table->DrawSplitter.SetCurrentChannel(window->DrawList, table->Bg1DrawChannelCurrent);
}

void    ImGui::TablePopBackgroundChannel()
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;
    ImGuiTable* table = g.CurrentTable;
    ImGuiTableColumn* column = &table->Columns[table->CurrentColumn];

    // Optimization: avoid PopClipRect() + SetCurrentChannel()
    SetWindowClipRectBeforeSetChannel(window, table->HostBackupClipRect);
    table->DrawSplitter.SetCurrentChannel(window->DrawList, column->DrawChannelCurrent);
}

// Return -1 when table is not hovered. return columns_count if the unused space at the right of visible columns is hovered.
int ImGui::TableGetHoveredColumn()
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    if (!table)
        return -1;
    return (int)table->HoveredColumnBody;
}

void ImGui::TableSetBgColor(ImGuiTableBgTarget bg_target, ImU32 color, int column_n)
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    IM_ASSERT(bg_target != ImGuiTableBgTarget_None);

    if (color == IM_COL32_DISABLE)
        color = 0;

    // We cannot draw neither the cell or row background immediately as we don't know the row height at this point in time.
    switch (bg_target)
    {
    case ImGuiTableBgTarget_CellBg:
    {
        if (table->RowPosY1 > table->InnerClipRect.Max.y) // Discard
            return;
        if (column_n == -1)
            column_n = table->CurrentColumn;
        if ((table->EnabledUnclippedMaskByIndex & ((ImU64)1 << column_n)) == 0)
            return;
        if (table->RowCellDataCurrent < 0 || table->RowCellData[table->RowCellDataCurrent].Column != column_n)
            table->RowCellDataCurrent++;
        ImGuiTableCellData* cell_data = &table->RowCellData[table->RowCellDataCurrent];
        cell_data->BgColor = color;
        cell_data->Column = (ImS8)column_n;
        break;
    }
    case ImGuiTableBgTarget_RowBg0:
    case ImGuiTableBgTarget_RowBg1:
    {
        if (table->RowPosY1 > table->InnerClipRect.Max.y) // Discard
            return;
        IM_ASSERT(column_n == -1);
        int bg_idx = (bg_target == ImGuiTableBgTarget_RowBg1) ? 1 : 0;
        table->RowBgColor[bg_idx] = color;
        break;
    }
    default:
        IM_ASSERT(0);
    }
}

//-------------------------------------------------------------------------
// [SECTION] Tables: Sorting
//-------------------------------------------------------------------------
// - TableGetSortSpecs()
// - TableGetColumnIsSorted()
// - TableFixColumnSortDirection() [Internal]
// - TableSetColumnSortDirection() [Internal]
// - TableSortSpecsSanitize() [Internal]
// - TableSortSpecsBuild() [Internal]
//-------------------------------------------------------------------------

// Return NULL if no sort specs (most often when ImGuiTableFlags_Sortable is not set)
// You can sort your data again when 'SpecsChanged == true'. It will be true with sorting specs have changed since
// last call, or the first time.
// Lifetime: don't hold on this pointer over multiple frames or past any subsequent call to BeginTable()!
ImGuiTableSortSpecs* ImGui::TableGetSortSpecs()
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    IM_ASSERT(table != NULL);

    if (!(table->Flags & ImGuiTableFlags_Sortable))
        return NULL;

    // Require layout (in case TableHeadersRow() hasn't been called) as it may alter IsSortSpecsDirty in some paths.
    if (!table->IsLayoutLocked)
        TableUpdateLayout(table);

    if (table->IsSortSpecsDirty)
        TableSortSpecsBuild(table);

    return table->SortSpecs.SpecsCount ? &table->SortSpecs : NULL;
}

bool ImGui::TableGetColumnIsSorted(int column_n)
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    if (!table)
        return false;
    if (column_n < 0)
        column_n = table->CurrentColumn;
    ImGuiTableColumn* column = &table->Columns[column_n];
    return (column->SortOrder != -1);
}

void ImGui::TableFixColumnSortDirection(ImGuiTableColumn* column)
{
    // Initial sort state
    if (column->SortDirection == ImGuiSortDirection_None)
        column->SortDirection = (column->Flags & ImGuiTableColumnFlags_PreferSortDescending) ? (ImS8)ImGuiSortDirection_Descending : (ImS8)(ImGuiSortDirection_Ascending);

    // Handle NoSortAscending/NoSortDescending
    if (column->SortDirection == ImGuiSortDirection_Ascending && (column->Flags & ImGuiTableColumnFlags_NoSortAscending))
        column->SortDirection = ImGuiSortDirection_Descending;
    else if (column->SortDirection == ImGuiSortDirection_Descending && (column->Flags & ImGuiTableColumnFlags_NoSortDescending))
        column->SortDirection = ImGuiSortDirection_Ascending;
}


// Note that the NoSortAscending/NoSortDescending flags are processed in TableSortSpecsSanitize(), and they may change/revert
// the value of SortDirection. We could technically also do it here but it would be unnecessary and duplicate code.
void ImGui::TableSetColumnSortDirection(int column_n, ImGuiSortDirection sort_direction, bool append_to_sort_specs)
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;

    if (!(table->Flags & ImGuiTableFlags_MultiSortable))
        append_to_sort_specs = false;

    ImS8 sort_order_max = 0;
    if (append_to_sort_specs)
        for (int other_column_n = 0; other_column_n < table->ColumnsCount; other_column_n++)
            sort_order_max = ImMax(sort_order_max, table->Columns[other_column_n].SortOrder);

    ImGuiTableColumn* column = &table->Columns[column_n];
    column->SortDirection = (ImS8)sort_direction;
    if (column->SortOrder == -1 || !append_to_sort_specs)
        column->SortOrder = append_to_sort_specs ? sort_order_max + 1 : 0;

    for (int other_column_n = 0; other_column_n < table->ColumnsCount; other_column_n++)
    {
        ImGuiTableColumn* other_column = &table->Columns[other_column_n];
        if (other_column != column && !append_to_sort_specs)
            other_column->SortOrder = -1;
        TableFixColumnSortDirection(other_column);
    }
    table->IsSettingsDirty = true;
    table->IsSortSpecsDirty = true;
}

void ImGui::TableSortSpecsSanitize(ImGuiTable* table)
{
    IM_ASSERT(table->Flags & ImGuiTableFlags_Sortable);

    // Clear SortOrder from hidden column and verify that there's no gap or duplicate.
    int sort_order_count = 0;
    ImU64 sort_order_mask = 0x00;
    for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
    {
        ImGuiTableColumn* column = &table->Columns[column_n];
        if (column->SortOrder != -1 && !column->IsEnabled)
            column->SortOrder = -1;
        if (column->SortOrder == -1)
            continue;
        sort_order_count++;
        sort_order_mask |= ((ImU64)1 << column->SortOrder);
        IM_ASSERT(sort_order_count < (int)sizeof(sort_order_mask) * 8);
    }

    const bool need_fix_linearize = ((ImU64)1 << sort_order_count) != (sort_order_mask + 1);
    const bool need_fix_single_sort_order = (sort_order_count > 1) && !(table->Flags & ImGuiTableFlags_MultiSortable);
    if (need_fix_linearize || need_fix_single_sort_order)
    {
        ImU64 fixed_mask = 0x00;
        for (int sort_n = 0; sort_n < sort_order_count; sort_n++)
        {
            // Fix: Rewrite sort order fields if needed so they have no gap or duplicate.
            // (e.g. SortOrder 0 disappeared, SortOrder 1..2 exists --> rewrite then as SortOrder 0..1)
            int column_with_smallest_sort_order = -1;
            for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
                if ((fixed_mask & ((ImU64)1 << (ImU64)column_n)) == 0 && table->Columns[column_n].SortOrder != -1)
                    if (column_with_smallest_sort_order == -1 || table->Columns[column_n].SortOrder < table->Columns[column_with_smallest_sort_order].SortOrder)
                        column_with_smallest_sort_order = column_n;
            IM_ASSERT(column_with_smallest_sort_order != -1);
            fixed_mask |= ((ImU64)1 << column_with_smallest_sort_order);
            table->Columns[column_with_smallest_sort_order].SortOrder = (ImS8)sort_n;

            // Fix: Make sure only one column has a SortOrder if ImGuiTableFlags_MultiSortable is not set.
            if (need_fix_single_sort_order)
            {
                sort_order_count = 1;
                for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
                    if (column_n != column_with_smallest_sort_order)
                        table->Columns[column_n].SortOrder = -1;
                break;
            }
        }
    }

    // Fallback default sort order (if no column had the ImGuiTableColumnFlags_DefaultSort flag)
    if (sort_order_count == 0)
        for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
        {
            ImGuiTableColumn* column = &table->Columns[column_n];
            if (column->IsEnabled && !(column->Flags & ImGuiTableColumnFlags_NoSort))
            {
                sort_order_count = 1;
                column->SortOrder = 0;
                TableFixColumnSortDirection(column);
                break;
            }
        }

    table->SortSpecsCount = (ImS8)sort_order_count;
}

void ImGui::TableSortSpecsBuild(ImGuiTable* table)
{
    IM_ASSERT(table->IsSortSpecsDirty);
    TableSortSpecsSanitize(table);

    // Write output
    table->SortSpecsData.resize(table->SortSpecsCount);
    for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
    {
        ImGuiTableColumn* column = &table->Columns[column_n];
        if (column->SortOrder == -1)
            continue;
        ImGuiTableSortSpecsColumn* sort_spec = &table->SortSpecsData[column->SortOrder];
        sort_spec->ColumnUserID = column->UserID;
        sort_spec->ColumnIndex = (ImU8)column_n;
        sort_spec->SortOrder = (ImU8)column->SortOrder;
        sort_spec->SortDirection = column->SortDirection;
    }
    table->SortSpecs.Specs = table->SortSpecsData.Data;
    table->SortSpecs.SpecsCount = table->SortSpecsData.Size;
    table->SortSpecs.SpecsDirty = true; // Mark as dirty for user
    table->IsSortSpecsDirty = false; // Mark as not dirty for us
}

//-------------------------------------------------------------------------
// [SECTION] Tables: Headers
//-------------------------------------------------------------------------
// - TableHeadersRow()
// - TableHeader()
//-------------------------------------------------------------------------

// This is a helper to output TableHeader() calls based on the column names declared in TableSetupColumn().
// The intent is that advanced users willing to create customized headers would not need to use this helper
// and can create their own! For example: TableHeader() may be preceeded by Checkbox() or other custom widgets.
// See 'Demo->Tables->Custom headers' for a demonstration of implementing a custom version of this.
void    ImGui::TableHeadersRow()
{
    ImGuiStyle& style = ImGui::GetStyle();

    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    IM_ASSERT(table != NULL && "Need to call TableHeadersRow() after BeginTable()!");

    // Calculate row height (for the unlikely case that labels may be are multi-line)
    // If we didn't do that, uneven header height would work but their highlight won't cover the full row height.
    float row_height = GetTextLineHeight();
    const float row_y1 = GetCursorScreenPos().y;
    const int columns_count = TableGetColumnCount();
    for (int column_n = 0; column_n < columns_count; column_n++)
        if (TableGetColumnIsEnabled(column_n))
            row_height = ImMax(row_height, CalcTextSize(TableGetColumnName(column_n)).y);
    row_height += style.CellPadding.y * 2.0f;

    // Open row
    TableNextRow(ImGuiTableRowFlags_Headers, row_height);
    if (table->HostSkipItems) // Merely an optimization, you may skip in your own code.
        return;

    // This for loop is constructed to not make use of internal functions,
    // as this is intended to be a base template to copy and build from.
    for (int column_n = 0; column_n < columns_count; column_n++)
    {
        if (!TableSetColumnIndex(column_n))
            continue;

        // [DEBUG] Test custom user elements
#if 0
        if (column_n < 2)
        {
            static bool b[2] = {};
            PushID(column_n);
            PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(0, 0));
            Checkbox("##", &b[column_n]);
            PopStyleVar();
            PopID();
            SameLine(0.0f, style.ItemInnerSpacing.x);
        }
#endif

        // Push an id to allow unnamed labels (generally accidental, but let's behave nicely with them)
        // - in your own code you may omit the PushID/PopID all-together, provided you know they won't collide
        // - table->InstanceCurrent is only >0 when we use multiple BeginTable/EndTable calls with same identifier.
        const char* name = TableGetColumnName(column_n);
        PushID(table->InstanceCurrent * table->ColumnsCount + column_n);
        TableHeader(name);
        PopID();
    }

    // Allow opening popup from the right-most section after the last column.
    // FIXME-TABLE: TableOpenContextMenu() is not public yet.
    ImVec2 mouse_pos = ImGui::GetMousePos();
    if (IsMouseReleased(1) && TableGetHoveredColumn() == columns_count)
        if (mouse_pos.y >= row_y1 && mouse_pos.y < row_y1 + row_height)
            TableOpenContextMenu(-1); // Will open a non-column-specific popup.
}

// Emit a column header (text + optional sort order)
// We cpu-clip text here so that all columns headers can be merged into a same draw call.
// Note that because of how we cpu-clip and display sorting indicators, you _cannot_ use SameLine() after a TableHeader()
// FIXME-TABLE: Style confusion between CellPadding.y and FramePadding.y
void    ImGui::TableHeader(const char* label)
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;
    if (window->SkipItems)
        return;

    ImGuiTable* table = g.CurrentTable;
    IM_ASSERT(table != NULL && "Need to call TableHeader() after BeginTable()!");
    IM_ASSERT(table->CurrentColumn != -1);
    const int column_n = table->CurrentColumn;
    ImGuiTableColumn* column = &table->Columns[column_n];

    // Label
    if (label == NULL)
        label = "";
    const char* label_end = FindRenderedTextEnd(label);
    ImVec2 label_size = CalcTextSize(label, label_end, true);
    ImVec2 label_pos = window->DC.CursorPos;

    // If we already got a row height, there's use that.
    // FIXME-TABLE-PADDING: Problem if the correct outer-padding CellBgRect strays off our ClipRect
    ImRect cell_r = TableGetCellBgRect(table, column_n);
    float label_height = ImMax(label_size.y, table->RowMinHeight - table->CellPaddingY * 2.0f);

    // Keep header highlighted when context menu is open.
    const bool selected = (table->IsContextPopupOpen && table->ContextPopupColumn == column_n && table->InstanceInteracted == table->InstanceCurrent);
    ImGuiID id = window->GetID(label);
    ImRect bb(cell_r.Min.x, cell_r.Min.y, cell_r.Max.x, ImMax(cell_r.Max.y, cell_r.Min.y + label_height + g.Style.CellPadding.y * 2.0f));
    ItemSize(ImVec2(0.0f, label_height)); // Don't declare unclipped width, it'll be fed ContentMaxPosHeadersIdeal
    if (!ItemAdd(bb, id))
        return;

    //GetForegroundDrawList()->AddRect(cell_r.Min, cell_r.Max, IM_COL32(255, 0, 0, 255)); // [DEBUG]
    //GetForegroundDrawList()->AddRect(bb.Min, bb.Max, IM_COL32(255, 0, 0, 255)); // [DEBUG]

    bool hovered, held;
    bool pressed = ButtonBehavior(bb, id, &hovered, &held, ImGuiButtonFlags_None);
    if (hovered || selected)
    {
        const ImU32 col = GetColorU32(held ? ImGuiCol_HeaderActive : hovered ? ImGuiCol_HeaderHovered : ImGuiCol_Header);
        //RenderFrame(bb.Min, bb.Max, col, false, 0.0f);
        TableSetBgColor(ImGuiTableBgTarget_CellBg, col, table->CurrentColumn);
        RenderNavHighlight(bb, id, ImGuiNavHighlightFlags_TypeThin | ImGuiNavHighlightFlags_NoRounding);
    }
    if (held)
        table->HeldHeaderColumn = (ImS8)column_n;
    window->DC.CursorPos.y -= g.Style.ItemSpacing.y * 0.5f;

    // Drag and drop to re-order columns.
    // FIXME-TABLE: Scroll request while reordering a column and it lands out of the scrolling zone.
    if (held && (table->Flags & ImGuiTableFlags_Reorderable) && IsMouseDragging(0) && !g.DragDropActive)
    {
        // While moving a column it will jump on the other side of the mouse, so we also test for MouseDelta.x
        table->ReorderColumn = (ImS8)column_n;
        table->InstanceInteracted = table->InstanceCurrent;

        // We don't reorder: through the frozen<>unfrozen line, or through a column that is marked with ImGuiTableColumnFlags_NoReorder.
        if (g.IO.MouseDelta.x < 0.0f && g.IO.MousePos.x < cell_r.Min.x)
            if (ImGuiTableColumn* prev_column = (column->PrevEnabledColumn != -1) ? &table->Columns[column->PrevEnabledColumn] : NULL)
                if (!((column->Flags | prev_column->Flags) & ImGuiTableColumnFlags_NoReorder))
                    if ((column->IndexWithinEnabledSet < table->FreezeColumnsRequest) == (prev_column->IndexWithinEnabledSet < table->FreezeColumnsRequest))
                        table->ReorderColumnDir = -1;
        if (g.IO.MouseDelta.x > 0.0f && g.IO.MousePos.x > cell_r.Max.x)
            if (ImGuiTableColumn* next_column = (column->NextEnabledColumn != -1) ? &table->Columns[column->NextEnabledColumn] : NULL)
                if (!((column->Flags | next_column->Flags) & ImGuiTableColumnFlags_NoReorder))
                    if ((column->IndexWithinEnabledSet < table->FreezeColumnsRequest) == (next_column->IndexWithinEnabledSet < table->FreezeColumnsRequest))
                        table->ReorderColumnDir = +1;
    }

    // Sort order arrow
    float w_arrow = 0.0f;
    float w_sort_text = 0.0f;
    float ellipsis_max = cell_r.Max.x;
    if ((table->Flags & ImGuiTableFlags_Sortable) && !(column->Flags & ImGuiTableColumnFlags_NoSort))
    {
        const float ARROW_SCALE = 0.65f;
        w_arrow = ImFloor(g.FontSize * ARROW_SCALE + g.Style.FramePadding.x);// table->CellPadding.x);
        if (column->SortOrder != -1)
        {
            w_sort_text = 0.0f;

            char sort_order_suf[8];
            if (column->SortOrder > 0)
            {
                ImFormatString(sort_order_suf, IM_ARRAYSIZE(sort_order_suf), "%d", column->SortOrder + 1);
                w_sort_text = g.Style.ItemInnerSpacing.x + CalcTextSize(sort_order_suf).x;
            }

            float x = ImMax(cell_r.Min.x, cell_r.Max.x - w_arrow - w_sort_text);
            ellipsis_max -= w_arrow + w_sort_text;

            float y = label_pos.y;
            ImU32 col = GetColorU32(ImGuiCol_Text);
            if (column->SortOrder > 0)
            {
                PushStyleColor(ImGuiCol_Text, GetColorU32(ImGuiCol_Text, 0.70f));
                RenderText(ImVec2(x + g.Style.ItemInnerSpacing.x, y), sort_order_suf);
                PopStyleColor();
                x += w_sort_text;
            }
            RenderArrow(window->DrawList, ImVec2(x, y), col, column->SortDirection == ImGuiSortDirection_Ascending ? ImGuiDir_Up : ImGuiDir_Down, ARROW_SCALE);
        }

        // Handle clicking on column header to adjust Sort Order
        if (pressed && table->ReorderColumn != column_n)
        {
            // Set new sort direction
            // - If the PreferSortDescending flag is set, we will default to a Descending direction on the first click.
            // - Note that the PreferSortAscending flag is never checked, it is essentially the default and therefore a no-op.
            ImGuiSortDirection sort_direction;
            if (column->SortOrder == -1)
                sort_direction = (column->Flags & ImGuiTableColumnFlags_PreferSortDescending) ? ImGuiSortDirection_Descending : ImGuiSortDirection_Ascending;
            else
                sort_direction = (column->SortDirection == ImGuiSortDirection_Ascending) ? ImGuiSortDirection_Descending : ImGuiSortDirection_Ascending;
            TableSetColumnSortDirection(column_n, sort_direction, g.IO.KeyShift);
        }
    }

    // Render clipped label. Clipping here ensure that in the majority of situations, all our header cells will
    // be merged into a single draw call.
    //window->DrawList->AddCircleFilled(ImVec2(ellipsis_max, label_pos.y), 40, IM_COL32_WHITE);
    RenderTextEllipsis(window->DrawList, label_pos, ImVec2(ellipsis_max, label_pos.y + label_height + g.Style.FramePadding.y), ellipsis_max, ellipsis_max, label, label_end, &label_size);

    const bool text_clipped = label_size.x > (ellipsis_max - label_pos.x);
    if (text_clipped && hovered && g.HoveredIdNotActiveTimer > g.TooltipSlowDelay)
        SetTooltip("%.*s", (int)(label_end - label), label);

    // We feed our unclipped width to the column without writing on CursorMaxPos, so that column is still considering for merging.
    float max_pos_x = label_pos.x + label_size.x + w_sort_text + w_arrow;
    column->ContentMaxXHeadersUsed = ImMax(column->ContentMaxXHeadersUsed, column->WorkMaxX);
    column->ContentMaxXHeadersIdeal = ImMax(column->ContentMaxXHeadersIdeal, max_pos_x);

    // We don't use BeginPopupContextItem() because we want the popup to stay up even after the column is hidden
    if (IsMouseReleased(1) && IsItemHovered())
        TableOpenContextMenu(column_n);
}

//-------------------------------------------------------------------------
// [SECTION] Tables: Context Menu
//-------------------------------------------------------------------------
// - TableOpenContextMenu() [Internal]
// - TableDrawContextMenu() [Internal]
//-------------------------------------------------------------------------

// Use -1 to open menu not specific to a given column.
void    ImGui::TableOpenContextMenu(int column_n)
{
    ImGuiContext& g = *GImGui;
    ImGuiTable* table = g.CurrentTable;
    if (column_n == -1 && table->CurrentColumn != -1)   // When called within a column automatically use this one (for consistency)
        column_n = table->CurrentColumn;
    if (column_n == table->ColumnsCount)                // To facilitate using with TableGetHoveredColumn()
        column_n = -1;
    IM_ASSERT(column_n >= -1 && column_n < table->ColumnsCount);
    if (table->Flags & (ImGuiTableFlags_Resizable | ImGuiTableFlags_Reorderable | ImGuiTableFlags_Hideable))
    {
        table->IsContextPopupOpen = true;
        table->ContextPopupColumn = (ImS8)column_n;
        table->InstanceInteracted = table->InstanceCurrent;
        const ImGuiID context_menu_id = ImHashStr("##ContextMenu", 0, table->ID);
        OpenPopupEx(context_menu_id, ImGuiPopupFlags_None);
    }
}

// Output context menu into current window (generally a popup)
// FIXME-TABLE: Ideally this should be writable by the user. Full programmatic access to that data?
void    ImGui::TableDrawContextMenu(ImGuiTable* table)
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;
    if (window->SkipItems)
        return;

    bool want_separator = false;
    const int column_n = (table->ContextPopupColumn >= 0 && table->ContextPopupColumn < table->ColumnsCount) ? table->ContextPopupColumn : -1;
    ImGuiTableColumn* column = (column_n != -1) ? &table->Columns[column_n] : NULL;

    // Sizing
    if (table->Flags & ImGuiTableFlags_Resizable)
    {
        if (column != NULL)
        {
            const bool can_resize = !(column->Flags & ImGuiTableColumnFlags_NoResize) && column->IsEnabled;
            if (MenuItem("Size column to fit", NULL, false, can_resize))
                TableSetColumnWidthAutoSingle(table, column_n);
        }

        const char* size_all_desc;
        if (table->ColumnsEnabledFixedCount == table->ColumnsEnabledCount)
            size_all_desc = "Size all columns to fit";          // All fixed
        else if (table->ColumnsEnabledFixedCount == 0)
            size_all_desc = "Size all columns to default";      // All stretch
        else
            size_all_desc = "Size all columns to fit/default";  // Mixed
        if (MenuItem(size_all_desc, NULL))
            TableSetColumnWidthAutoAll(table);
        want_separator = true;
    }

    // Ordering
    if (table->Flags & ImGuiTableFlags_Reorderable)
    {
        if (MenuItem("Reset order", NULL, false, !table->IsDefaultDisplayOrder))
            table->IsResetDisplayOrderRequest = true;
        want_separator = true;
    }

    // Sorting
    // (modify TableOpenContextMenu() to add _Sortable flag if enabling this)
#if 0
    if ((table->Flags & ImGuiTableFlags_Sortable) && column != NULL && (column->Flags & ImGuiTableColumnFlags_NoSort) == 0)
    {
        if (want_separator)
            Separator();
        want_separator = true;

        bool append_to_sort_specs = g.IO.KeyShift;
        if (MenuItem("Sort in Ascending Order", NULL, column->SortOrder != -1 && column->SortDirection == ImGuiSortDirection_Ascending, (column->Flags & ImGuiTableColumnFlags_NoSortAscending) == 0))
            TableSetColumnSortDirection(table, column_n, ImGuiSortDirection_Ascending, append_to_sort_specs);
        if (MenuItem("Sort in Descending Order", NULL, column->SortOrder != -1 && column->SortDirection == ImGuiSortDirection_Descending, (column->Flags & ImGuiTableColumnFlags_NoSortDescending) == 0))
            TableSetColumnSortDirection(table, column_n, ImGuiSortDirection_Descending, append_to_sort_specs);
    }
#endif

    // Hiding / Visibility
    if (table->Flags & ImGuiTableFlags_Hideable)
    {
        if (want_separator)
            Separator();
        want_separator = true;

        PushItemFlag(ImGuiItemFlags_SelectableDontClosePopup, true);
        for (int other_column_n = 0; other_column_n < table->ColumnsCount; other_column_n++)
        {
            ImGuiTableColumn* other_column = &table->Columns[other_column_n];
            const char* name = TableGetColumnName(table, other_column_n);
            if (name == NULL || name[0] == 0)
                name = "<Unknown>";

            // Make sure we can't hide the last active column
            bool menu_item_active = (other_column->Flags & ImGuiTableColumnFlags_NoHide) ? false : true;
            if (other_column->IsEnabled && table->ColumnsEnabledCount <= 1)
                menu_item_active = false;
            if (MenuItem(name, NULL, other_column->IsEnabled, menu_item_active))
                other_column->IsEnabledNextFrame = !other_column->IsEnabled;
        }
        PopItemFlag();
    }
}

//-------------------------------------------------------------------------
// [SECTION] Tables: Settings (.ini data)
//-------------------------------------------------------------------------
// - TableSettingsInit() [Internal]
// - TableSettingsCalcChunkSize() [Internal]
// - TableSettingsCreate() [Internal]
// - TableSettingsFindByID() [Internal]
// - TableSettingsClearByID() [Internal]
// - TableGetBoundSettings() [Internal]
// - TableSaveSettings() [Internal]
// - TableLoadSettings() [Internal]
// - TableSettingsHandler_ClearAll() [Internal]
// - TableSettingsHandler_ApplyAll() [Internal]
// - TableSettingsHandler_ReadOpen() [Internal]
// - TableSettingsHandler_ReadLine() [Internal]
// - TableSettingsHandler_WriteAll() [Internal]
// - TableSettingsInstallHandler() [Internal]
//-------------------------------------------------------------------------
// [Init] 1: TableSettingsHandler_ReadXXXX()   Load and parse .ini file into TableSettings.
// [Main] 2: TableLoadSettings()               When table is created, bind Table to TableSettings, serialize TableSettings data into Table.
// [Main] 3: TableSaveSettings()               When table properties are modified, serialize Table data into bound or new TableSettings, mark .ini as dirty.
// [Main] 4: TableSettingsHandler_WriteAll()   When .ini file is dirty (which can come from other source), save TableSettings into .ini file.
//-------------------------------------------------------------------------

// Clear and initialize empty settings instance
static void TableSettingsInit(ImGuiTableSettings* settings, ImGuiID id, int columns_count, int columns_count_max)
{
    IM_PLACEMENT_NEW(settings) ImGuiTableSettings();
    ImGuiTableColumnSettings* settings_column = settings->GetColumnSettings();
    for (int n = 0; n < columns_count_max; n++, settings_column++)
        IM_PLACEMENT_NEW(settings_column) ImGuiTableColumnSettings();
    settings->ID = id;
    settings->ColumnsCount = (ImS8)columns_count;
    settings->ColumnsCountMax = (ImS8)columns_count_max;
    settings->WantApply = true;
}

static size_t TableSettingsCalcChunkSize(int columns_count)
{
    return sizeof(ImGuiTableSettings) + (size_t)columns_count * sizeof(ImGuiTableColumnSettings);
}

ImGuiTableSettings* ImGui::TableSettingsCreate(ImGuiID id, int columns_count)
{
    ImGuiContext& g = *GImGui;
    ImGuiTableSettings* settings = g.SettingsTables.alloc_chunk(TableSettingsCalcChunkSize(columns_count));
    TableSettingsInit(settings, id, columns_count, columns_count);
    return settings;
}

// Find existing settings
ImGuiTableSettings* ImGui::TableSettingsFindByID(ImGuiID id)
{
    // FIXME-OPT: Might want to store a lookup map for this?
    ImGuiContext& g = *GImGui;
    for (ImGuiTableSettings* settings = g.SettingsTables.begin(); settings != NULL; settings = g.SettingsTables.next_chunk(settings))
        if (settings->ID == id)
            return settings;
    return NULL;
}

void ImGui::TableSettingsClearByID(ImGuiID id)
{
    if (ImGuiTableSettings* settings = TableSettingsFindByID(id))
        settings->ID = 0;
}

// Get settings for a given table, NULL if none
ImGuiTableSettings* ImGui::TableGetBoundSettings(ImGuiTable* table)
{
    if (table->SettingsOffset != -1)
    {
        ImGuiContext& g = *GImGui;
        ImGuiTableSettings* settings = g.SettingsTables.ptr_from_offset(table->SettingsOffset);
        IM_ASSERT(settings->ID == table->ID);
        if (settings->ColumnsCountMax >= table->ColumnsCount)
            return settings; // OK
        settings->ID = 0; // Invalidate storage, we won't fit because of a count change
    }
    return NULL;
}

void ImGui::TableSaveSettings(ImGuiTable* table)
{
    table->IsSettingsDirty = false;
    if (table->Flags & ImGuiTableFlags_NoSavedSettings)
        return;

    // Bind or create settings data
    ImGuiContext& g = *GImGui;
    ImGuiTableSettings* settings = TableGetBoundSettings(table);
    if (settings == NULL)
    {
        settings = TableSettingsCreate(table->ID, table->ColumnsCount);
        table->SettingsOffset = g.SettingsTables.offset_from_ptr(settings);
    }
    settings->ColumnsCount = (ImS8)table->ColumnsCount;

    // Serialize ImGuiTable/ImGuiTableColumn into ImGuiTableSettings/ImGuiTableColumnSettings
    IM_ASSERT(settings->ID == table->ID);
    IM_ASSERT(settings->ColumnsCount == table->ColumnsCount && settings->ColumnsCountMax >= settings->ColumnsCount);
    ImGuiTableColumn* column = table->Columns.Data;
    ImGuiTableColumnSettings* column_settings = settings->GetColumnSettings();

    bool save_ref_scale = false;
    settings->SaveFlags = ImGuiTableFlags_None;
    for (int n = 0; n < table->ColumnsCount; n++, column++, column_settings++)
    {
        const float width_or_weight = (column->Flags & ImGuiTableColumnFlags_WidthStretch) ? column->StretchWeight : column->WidthRequest;
        column_settings->WidthOrWeight = width_or_weight;
        column_settings->Index = (ImS8)n;
        column_settings->DisplayOrder = column->DisplayOrder;
        column_settings->SortOrder = column->SortOrder;
        column_settings->SortDirection = column->SortDirection;
        column_settings->IsEnabled = column->IsEnabled;
        column_settings->IsStretch = (column->Flags & ImGuiTableColumnFlags_WidthStretch) ? 1 : 0;
        if ((column->Flags & ImGuiTableColumnFlags_WidthStretch) == 0)
            save_ref_scale = true;

        // We skip saving some data in the .ini file when they are unnecessary to restore our state.
        // Note that fixed width where initial width was derived from auto-fit will always be saved as InitStretchWeightOrWidth will be 0.0f.
        // FIXME-TABLE: We don't have logic to easily compare SortOrder to DefaultSortOrder yet so it's always saved when present.
        if (width_or_weight != column->InitStretchWeightOrWidth)
            settings->SaveFlags |= ImGuiTableFlags_Resizable;
        if (column->DisplayOrder != n)
            settings->SaveFlags |= ImGuiTableFlags_Reorderable;
        if (column->SortOrder != -1)
            settings->SaveFlags |= ImGuiTableFlags_Sortable;
        if (column->IsEnabled != ((column->Flags & ImGuiTableColumnFlags_DefaultHide) == 0))
            settings->SaveFlags |= ImGuiTableFlags_Hideable;
    }
    settings->SaveFlags &= table->Flags;
    settings->RefScale = save_ref_scale ? table->RefScale : 0.0f;

    MarkIniSettingsDirty();
}

void ImGui::TableLoadSettings(ImGuiTable* table)
{
    ImGuiContext& g = *GImGui;
    table->IsSettingsRequestLoad = false;
    if (table->Flags & ImGuiTableFlags_NoSavedSettings)
        return;

    // Bind settings
    ImGuiTableSettings* settings;
    if (table->SettingsOffset == -1)
    {
        settings = TableSettingsFindByID(table->ID);
        if (settings == NULL)
            return;
        if (settings->ColumnsCount != table->ColumnsCount) // Allow settings if columns count changed. We could otherwise decide to return...
            table->IsSettingsDirty = true;
        table->SettingsOffset = g.SettingsTables.offset_from_ptr(settings);
    }
    else
    {
        settings = TableGetBoundSettings(table);
    }

    table->SettingsLoadedFlags = settings->SaveFlags;
    table->RefScale = settings->RefScale;

    // Serialize ImGuiTableSettings/ImGuiTableColumnSettings into ImGuiTable/ImGuiTableColumn
    ImGuiTableColumnSettings* column_settings = settings->GetColumnSettings();
    for (int data_n = 0; data_n < settings->ColumnsCount; data_n++, column_settings++)
    {
        int column_n = column_settings->Index;
        if (column_n < 0 || column_n >= table->ColumnsCount)
            continue;

        ImGuiTableColumn* column = &table->Columns[column_n];
        if (settings->SaveFlags & ImGuiTableFlags_Resizable)
        {
            if (column_settings->IsStretch)
                column->StretchWeight = column_settings->WidthOrWeight;
            else
                column->WidthRequest = column_settings->WidthOrWeight;
            column->AutoFitQueue = 0x00;
        }
        if (settings->SaveFlags & ImGuiTableFlags_Reorderable)
            column->DisplayOrder = column_settings->DisplayOrder;
        else
            column->DisplayOrder = (ImS8)column_n;
        column->IsEnabled = column->IsEnabledNextFrame = column_settings->IsEnabled;
        column->SortOrder = column_settings->SortOrder;
        column->SortDirection = column_settings->SortDirection;
    }

    // FIXME-TABLE: Need to validate .ini data
    for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
        table->DisplayOrderToIndex[table->Columns[column_n].DisplayOrder] = (ImS8)column_n;
}

static void TableSettingsHandler_ClearAll(ImGuiContext* ctx, ImGuiSettingsHandler*)
{
    ImGuiContext& g = *ctx;
    for (int i = 0; i != g.Tables.GetSize(); i++)
        g.Tables.GetByIndex(i)->SettingsOffset = -1;
    g.SettingsTables.clear();
}

// Apply to existing windows (if any)
static void TableSettingsHandler_ApplyAll(ImGuiContext* ctx, ImGuiSettingsHandler*)
{
    ImGuiContext& g = *ctx;
    for (int i = 0; i != g.Tables.GetSize(); i++)
    {
        ImGuiTable* table = g.Tables.GetByIndex(i);
        table->IsSettingsRequestLoad = true;
        table->SettingsOffset = -1;
    }
}

static void* TableSettingsHandler_ReadOpen(ImGuiContext*, ImGuiSettingsHandler*, const char* name)
{
    ImGuiID id = 0;
    int columns_count = 0;
    if (sscanf(name, "0x%08X,%d", &id, &columns_count) < 2)
        return NULL;

    if (ImGuiTableSettings* settings = ImGui::TableSettingsFindByID(id))
    {
        if (settings->ColumnsCountMax >= columns_count)
        {
            TableSettingsInit(settings, id, columns_count, settings->ColumnsCountMax); // Recycle
            return settings;
        }
        settings->ID = 0; // Invalidate storage, we won't fit because of a count change
    }
    return ImGui::TableSettingsCreate(id, columns_count);
}

static void TableSettingsHandler_ReadLine(ImGuiContext*, ImGuiSettingsHandler*, void* entry, const char* line)
{
    // "Column 0  UserID=0x42AD2D21 Width=100 Visible=1 Order=0 Sort=0v"
    ImGuiTableSettings* settings = (ImGuiTableSettings*)entry;
    float f = 0.0f;
    int column_n = 0, r = 0, n = 0;

    if (sscanf(line, "RefScale=%f", &f) == 1) { settings->RefScale = f; return; }

    if (sscanf(line, "Column %d%n", &column_n, &r) == 1)
    {
        if (column_n < 0 || column_n >= settings->ColumnsCount)
            return;
        line = ImStrSkipBlank(line + r);
        char c = 0;
        ImGuiTableColumnSettings* column = settings->GetColumnSettings() + column_n;
        column->Index = (ImS8)column_n;
        if (sscanf(line, "UserID=0x%08X%n", (ImU32*)&n, &r)==1) { line = ImStrSkipBlank(line + r); column->UserID = (ImGuiID)n; }
        if (sscanf(line, "Width=%d%n", &n, &r) == 1)            { line = ImStrSkipBlank(line + r); column->WidthOrWeight = (float)n; column->IsStretch = 0; settings->SaveFlags |= ImGuiTableFlags_Resizable; }
        if (sscanf(line, "Weight=%f%n", &f, &r) == 1)           { line = ImStrSkipBlank(line + r); column->WidthOrWeight = f; column->IsStretch = 1; settings->SaveFlags |= ImGuiTableFlags_Resizable; }
        if (sscanf(line, "Visible=%d%n", &n, &r) == 1)          { line = ImStrSkipBlank(line + r); column->IsEnabled = (ImU8)n; settings->SaveFlags |= ImGuiTableFlags_Hideable; }
        if (sscanf(line, "Order=%d%n", &n, &r) == 1)            { line = ImStrSkipBlank(line + r); column->DisplayOrder = (ImS8)n; settings->SaveFlags |= ImGuiTableFlags_Reorderable; }
        if (sscanf(line, "Sort=%d%c%n", &n, &c, &r) == 2)       { line = ImStrSkipBlank(line + r); column->SortOrder = (ImS8)n; column->SortDirection = (c == '^') ? ImGuiSortDirection_Descending : ImGuiSortDirection_Ascending; settings->SaveFlags |= ImGuiTableFlags_Sortable; }
    }
}

static void TableSettingsHandler_WriteAll(ImGuiContext* ctx, ImGuiSettingsHandler* handler, ImGuiTextBuffer* buf)
{
    ImGuiContext& g = *ctx;
    for (ImGuiTableSettings* settings = g.SettingsTables.begin(); settings != NULL; settings = g.SettingsTables.next_chunk(settings))
    {
        if (settings->ID == 0) // Skip ditched settings
            continue;

        // TableSaveSettings() may clear some of those flags when we establish that the data can be stripped
        // (e.g. Order was unchanged)
        const bool save_size    = (settings->SaveFlags & ImGuiTableFlags_Resizable) != 0;
        const bool save_visible = (settings->SaveFlags & ImGuiTableFlags_Hideable) != 0;
        const bool save_order   = (settings->SaveFlags & ImGuiTableFlags_Reorderable) != 0;
        const bool save_sort    = (settings->SaveFlags & ImGuiTableFlags_Sortable) != 0;
        if (!save_size && !save_visible && !save_order && !save_sort)
            continue;

        buf->reserve(buf->size() + 30 + settings->ColumnsCount * 50); // ballpark reserve
        buf->appendf("[%s][0x%08X,%d]\n", handler->TypeName, settings->ID, settings->ColumnsCount);
        if (settings->RefScale != 0.0f)
            buf->appendf("RefScale=%g\n", settings->RefScale);
        ImGuiTableColumnSettings* column = settings->GetColumnSettings();
        for (int column_n = 0; column_n < settings->ColumnsCount; column_n++, column++)
        {
            // "Column 0  UserID=0x42AD2D21 Width=100 Visible=1 Order=0 Sort=0v"
            buf->appendf("Column %-2d", column_n);
            if (column->UserID != 0)                    buf->appendf(" UserID=%08X", column->UserID);
            if (save_size && column->IsStretch)         buf->appendf(" Weight=%.4f", column->WidthOrWeight);
            if (save_size && !column->IsStretch)        buf->appendf(" Width=%d", (int)column->WidthOrWeight);
            if (save_visible)                           buf->appendf(" Visible=%d", column->IsEnabled);
            if (save_order)                             buf->appendf(" Order=%d", column->DisplayOrder);
            if (save_sort && column->SortOrder != -1)   buf->appendf(" Sort=%d%c", column->SortOrder, (column->SortDirection == ImGuiSortDirection_Ascending) ? 'v' : '^');
            buf->append("\n");
        }
        buf->append("\n");
    }
}

void    ImGui::TableSettingsInstallHandler(ImGuiContext* context)
{
    ImGuiContext& g = *context;
    ImGuiSettingsHandler ini_handler;
    ini_handler.TypeName = "Table";
    ini_handler.TypeHash = ImHashStr("Table");
    ini_handler.ClearAllFn = TableSettingsHandler_ClearAll;
    ini_handler.ReadOpenFn = TableSettingsHandler_ReadOpen;
    ini_handler.ReadLineFn = TableSettingsHandler_ReadLine;
    ini_handler.ApplyAllFn = TableSettingsHandler_ApplyAll;
    ini_handler.WriteAllFn = TableSettingsHandler_WriteAll;
    g.SettingsHandlers.push_back(ini_handler);
}

//-------------------------------------------------------------------------
// [SECTION] Tables: Garbage Collection
//-------------------------------------------------------------------------
// - TableRemove() [Internal]
// - TableGcCompactTransientBuffers() [Internal]
// - TableGcCompactSettings() [Internal]
//-------------------------------------------------------------------------

// Remove Table (currently only used by TestEngine)
void    ImGui::TableRemove(ImGuiTable* table)
{
    //IMGUI_DEBUG_LOG("TableRemove() id=0x%08X\n", table->ID);
    ImGuiContext& g = *GImGui;
    int table_idx = g.Tables.GetIndex(table);
    //memset(table->RawData.Data, 0, table->RawData.size_in_bytes());
    //memset(table, 0, sizeof(ImGuiTable));
    g.Tables.Remove(table->ID, table);
    g.TablesLastTimeActive[table_idx] = -1.0f;
}

// Free up/compact internal Table buffers for when it gets unused
void    ImGui::TableGcCompactTransientBuffers(ImGuiTable* table)
{
    //IMGUI_DEBUG_LOG("TableGcCompactTransientBuffers() id=0x%08X\n", table->ID);
    ImGuiContext& g = *GImGui;
    IM_ASSERT(table->MemoryCompacted == false);
    table->DrawSplitter.ClearFreeMemory();
    table->SortSpecsData.clear();
    table->SortSpecs.Specs = NULL;
    table->IsSortSpecsDirty = true;
    table->ColumnsNames.clear();
    table->MemoryCompacted = true;
    for (int n = 0; n < table->ColumnsCount; n++)
        table->Columns[n].NameOffset = -1;
    g.TablesLastTimeActive[g.Tables.GetIndex(table)] = -1.0f;
}

// Compact and remove unused settings data (currently only used by TestEngine)
void ImGui::TableGcCompactSettings()
{
    ImGuiContext& g = *GImGui;
    int required_memory = 0;
    for (ImGuiTableSettings* settings = g.SettingsTables.begin(); settings != NULL; settings = g.SettingsTables.next_chunk(settings))
        if (settings->ID != 0)
            required_memory += (int)TableSettingsCalcChunkSize(settings->ColumnsCount);
    if (required_memory == g.SettingsTables.Buf.Size)
        return;
    ImChunkStream<ImGuiTableSettings> new_chunk_stream;
    new_chunk_stream.Buf.reserve(required_memory);
    for (ImGuiTableSettings* settings = g.SettingsTables.begin(); settings != NULL; settings = g.SettingsTables.next_chunk(settings))
        if (settings->ID != 0)
            memcpy(new_chunk_stream.alloc_chunk(TableSettingsCalcChunkSize(settings->ColumnsCount)), settings, TableSettingsCalcChunkSize(settings->ColumnsCount));
    g.SettingsTables.swap(new_chunk_stream);
}


//-------------------------------------------------------------------------
// [SECTION] Tables: Debugging
//-------------------------------------------------------------------------
// - DebugNodeTable() [Internal]
//-------------------------------------------------------------------------

#ifndef IMGUI_DISABLE_METRICS_WINDOW

void ImGui::DebugNodeTable(ImGuiTable* table)
{
    char buf[512];
    char* p = buf;
    const char* buf_end = buf + IM_ARRAYSIZE(buf);
    const bool is_active = (table->LastFrameActive >= ImGui::GetFrameCount() - 2);
    ImFormatString(p, buf_end - p, "Table 0x%08X (%d columns, in '%s')%s", table->ID, table->ColumnsCount, table->OuterWindow->Name, is_active ? "" : " *Inactive*");
    if (!is_active) { PushStyleColor(ImGuiCol_Text, GetStyleColorVec4(ImGuiCol_TextDisabled)); }
    bool open = TreeNode(table, "%s", buf);
    if (!is_active) { PopStyleColor(); }
    if (IsItemHovered())
        GetForegroundDrawList()->AddRect(table->OuterRect.Min, table->OuterRect.Max, IM_COL32(255, 255, 0, 255));
    if (!open)
        return;
    BulletText("OuterRect: Pos: (%.1f,%.1f) Size: (%.1f,%.1f)", table->OuterRect.Min.x, table->OuterRect.Min.y, table->OuterRect.GetWidth(), table->OuterRect.GetHeight());
    BulletText("ColumnsWidth: %.1f, AutoFitWidth: %.1f, InnerWidth: %.1f%s", table->ColumnsTotalWidth, table->ColumnsAutoFitWidth, table->InnerWidth, table->InnerWidth == 0.0f ? " (auto)" : "");
    BulletText("CellPaddingX: %.1f, CellSpacingX: %.1f/%.1f, OuterPaddingX: %.1f", table->CellPaddingX, table->CellSpacingX1, table->CellSpacingX2, table->OuterPaddingX);
    BulletText("HoveredColumnBody: %d, HoveredColumnBorder: %d", table->HoveredColumnBody, table->HoveredColumnBorder);
    BulletText("ResizedColumn: %d, ReorderColumn: %d, HeldHeaderColumn: %d", table->ResizedColumn, table->ReorderColumn, table->HeldHeaderColumn);
    //BulletText("BgDrawChannels: %d/%d", 0, table->BgDrawChannelUnfrozen);
    for (int n = 0; n < table->ColumnsCount; n++)
    {
        ImGuiTableColumn* column = &table->Columns[n];
        const char* name = TableGetColumnName(table, n);
        ImFormatString(buf, IM_ARRAYSIZE(buf),
            "Column %d order %d name '%s': offset %+.2f to %+.2f\n"
            "Visible: %d, Clipped: %d, SkipItems: %d, DrawChannels: %d,%d\n"
            "WidthGiven: %.1f, Request/Auto: %.1f/%.1f, StretchWeight: %.3f\n"
            "MinX: %.1f, MaxX: %.1f (%+.1f), ClipRect: %.1f to %.1f (+%.1f)\n"
            "ContentWidth: %.1f,%.1f, HeadersUsed/Ideal %.1f/%.1f\n"
            "Sort: %d%s, UserID: 0x%08X, Flags: 0x%04X: %s%s%s%s..",
            n, column->DisplayOrder, name, column->MinX - table->WorkRect.Min.x, column->MaxX - table->WorkRect.Min.x,
            column->IsEnabled, column->IsClipped, column->IsSkipItems, column->DrawChannelFrozen, column->DrawChannelUnfrozen,
            column->WidthGiven, column->WidthRequest, column->WidthAuto, column->StretchWeight,
            column->MinX, column->MaxX, column->MaxX - column->MinX, column->ClipRect.Min.x, column->ClipRect.Max.x, column->ClipRect.Max.x - column->ClipRect.Min.x,
            column->ContentMaxXFrozen - column->WorkMinX, column->ContentMaxXUnfrozen - column->WorkMinX, column->ContentMaxXHeadersUsed - column->WorkMinX, column->ContentMaxXHeadersIdeal - column->WorkMinX,
            column->SortOrder, (column->SortDirection == ImGuiSortDirection_Ascending) ? " (Asc)" : (column->SortDirection == ImGuiSortDirection_Descending) ? " (Des)" : "", column->UserID, column->Flags,
            (column->Flags & ImGuiTableColumnFlags_WidthStretch) ? "WidthStretch " : "",
            (column->Flags & ImGuiTableColumnFlags_WidthFixed) ? "WidthFixed " : "",
            (column->Flags & ImGuiTableColumnFlags_WidthAutoResize) ? "WidthAutoResize " : "",
            (column->Flags & ImGuiTableColumnFlags_NoResize) ? "NoResize " : "");
        Bullet();
        Selectable(buf);
        if (IsItemHovered())
        {
            ImRect r(column->MinX, table->OuterRect.Min.y, column->MaxX, table->OuterRect.Max.y);
            GetForegroundDrawList()->AddRect(r.Min, r.Max, IM_COL32(255, 255, 0, 255));
        }
    }
    if (ImGuiTableSettings* settings = TableGetBoundSettings(table))
        DebugNodeTableSettings(settings);
    TreePop();
}

void ImGui::DebugNodeTableSettings(ImGuiTableSettings* settings)
{
    if (!TreeNode((void*)(intptr_t)settings->ID, "Settings 0x%08X (%d columns)", settings->ID, settings->ColumnsCount))
        return;
    BulletText("SaveFlags: 0x%08X", settings->SaveFlags);
    BulletText("ColumnsCount: %d (max %d)", settings->ColumnsCount, settings->ColumnsCountMax);
    for (int n = 0; n < settings->ColumnsCount; n++)
    {
        ImGuiTableColumnSettings* column_settings = &settings->GetColumnSettings()[n];
        ImGuiSortDirection sort_dir = (column_settings->SortOrder != -1) ? (ImGuiSortDirection)column_settings->SortDirection : ImGuiSortDirection_None;
        BulletText("Column %d Order %d SortOrder %d %s Vis %d %s %7.3f UserID 0x%08X",
            n, column_settings->DisplayOrder, column_settings->SortOrder,
            (sort_dir == ImGuiSortDirection_Ascending) ? "Asc" : (sort_dir == ImGuiSortDirection_Descending) ? "Des" : "---",
            column_settings->IsEnabled, column_settings->IsStretch ? "Weight" : "Width ", column_settings->WidthOrWeight, column_settings->UserID);
    }
    TreePop();
}

#endif // #ifndef IMGUI_DISABLE_METRICS_WINDOW


//-------------------------------------------------------------------------
// [SECTION] Columns, BeginColumns, EndColumns, etc.
// (This is a legacy API, prefer using BeginTable/EndTable!)
//-------------------------------------------------------------------------
// - SetWindowClipRectBeforeSetChannel() [Internal]
// - GetColumnIndex()
// - GetColumnsCount()
// - GetColumnOffset()
// - GetColumnWidth()
// - SetColumnOffset()
// - SetColumnWidth()
// - PushColumnClipRect() [Internal]
// - PushColumnsBackground() [Internal]
// - PopColumnsBackground() [Internal]
// - FindOrCreateColumns() [Internal]
// - GetColumnsID() [Internal]
// - BeginColumns()
// - NextColumn()
// - EndColumns()
// - Columns()
//-------------------------------------------------------------------------

// [Internal] Small optimization to avoid calls to PopClipRect/SetCurrentChannel/PushClipRect in sequences,
// they would meddle many times with the underlying ImDrawCmd.
// Instead, we do a preemptive overwrite of clipping rectangle _without_ altering the command-buffer and let
// the subsequent single call to SetCurrentChannel() does it things once.
void ImGui::SetWindowClipRectBeforeSetChannel(ImGuiWindow* window, const ImRect& clip_rect)
{
    ImVec4 clip_rect_vec4 = clip_rect.ToVec4();
    window->ClipRect = clip_rect;
    window->DrawList->_CmdHeader.ClipRect = clip_rect_vec4;
    window->DrawList->_ClipRectStack.Data[window->DrawList->_ClipRectStack.Size - 1] = clip_rect_vec4;
}

int ImGui::GetColumnIndex()
{
    ImGuiWindow* window = GetCurrentWindowRead();
    return window->DC.CurrentColumns ? window->DC.CurrentColumns->Current : 0;
}

int ImGui::GetColumnsCount()
{
    ImGuiWindow* window = GetCurrentWindowRead();
    return window->DC.CurrentColumns ? window->DC.CurrentColumns->Count : 1;
}

float ImGui::GetColumnOffsetFromNorm(const ImGuiOldColumns* columns, float offset_norm)
{
    return offset_norm * (columns->OffMaxX - columns->OffMinX);
}

float ImGui::GetColumnNormFromOffset(const ImGuiOldColumns* columns, float offset)
{
    return offset / (columns->OffMaxX - columns->OffMinX);
}

static const float COLUMNS_HIT_RECT_HALF_WIDTH = 4.0f;

static float GetDraggedColumnOffset(ImGuiOldColumns* columns, int column_index)
{
    // Active (dragged) column always follow mouse. The reason we need this is that dragging a column to the right edge of an auto-resizing
    // window creates a feedback loop because we store normalized positions. So while dragging we enforce absolute positioning.
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;
    IM_ASSERT(column_index > 0); // We are not supposed to drag column 0.
    IM_ASSERT(g.ActiveId == columns->ID + ImGuiID(column_index));

    float x = g.IO.MousePos.x - g.ActiveIdClickOffset.x + COLUMNS_HIT_RECT_HALF_WIDTH - window->Pos.x;
    x = ImMax(x, ImGui::GetColumnOffset(column_index - 1) + g.Style.ColumnsMinSpacing);
    if ((columns->Flags & ImGuiOldColumnFlags_NoPreserveWidths))
        x = ImMin(x, ImGui::GetColumnOffset(column_index + 1) - g.Style.ColumnsMinSpacing);

    return x;
}

float ImGui::GetColumnOffset(int column_index)
{
    ImGuiWindow* window = GetCurrentWindowRead();
    ImGuiOldColumns* columns = window->DC.CurrentColumns;
    if (columns == NULL)
        return 0.0f;

    if (column_index < 0)
        column_index = columns->Current;
    IM_ASSERT(column_index < columns->Columns.Size);

    const float t = columns->Columns[column_index].OffsetNorm;
    const float x_offset = ImLerp(columns->OffMinX, columns->OffMaxX, t);
    return x_offset;
}

static float GetColumnWidthEx(ImGuiOldColumns* columns, int column_index, bool before_resize = false)
{
    if (column_index < 0)
        column_index = columns->Current;

    float offset_norm;
    if (before_resize)
        offset_norm = columns->Columns[column_index + 1].OffsetNormBeforeResize - columns->Columns[column_index].OffsetNormBeforeResize;
    else
        offset_norm = columns->Columns[column_index + 1].OffsetNorm - columns->Columns[column_index].OffsetNorm;
    return ImGui::GetColumnOffsetFromNorm(columns, offset_norm);
}

float ImGui::GetColumnWidth(int column_index)
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;
    ImGuiOldColumns* columns = window->DC.CurrentColumns;
    if (columns == NULL)
        return GetContentRegionAvail().x;

    if (column_index < 0)
        column_index = columns->Current;
    return GetColumnOffsetFromNorm(columns, columns->Columns[column_index + 1].OffsetNorm - columns->Columns[column_index].OffsetNorm);
}

void ImGui::SetColumnOffset(int column_index, float offset)
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;
    ImGuiOldColumns* columns = window->DC.CurrentColumns;
    IM_ASSERT(columns != NULL);

    if (column_index < 0)
        column_index = columns->Current;
    IM_ASSERT(column_index < columns->Columns.Size);

    const bool preserve_width = !(columns->Flags & ImGuiOldColumnFlags_NoPreserveWidths) && (column_index < columns->Count - 1);
    const float width = preserve_width ? GetColumnWidthEx(columns, column_index, columns->IsBeingResized) : 0.0f;

    if (!(columns->Flags & ImGuiOldColumnFlags_NoForceWithinWindow))
        offset = ImMin(offset, columns->OffMaxX - g.Style.ColumnsMinSpacing * (columns->Count - column_index));
    columns->Columns[column_index].OffsetNorm = GetColumnNormFromOffset(columns, offset - columns->OffMinX);

    if (preserve_width)
        SetColumnOffset(column_index + 1, offset + ImMax(g.Style.ColumnsMinSpacing, width));
}

void ImGui::SetColumnWidth(int column_index, float width)
{
    ImGuiWindow* window = GetCurrentWindowRead();
    ImGuiOldColumns* columns = window->DC.CurrentColumns;
    IM_ASSERT(columns != NULL);

    if (column_index < 0)
        column_index = columns->Current;
    SetColumnOffset(column_index + 1, GetColumnOffset(column_index) + width);
}

void ImGui::PushColumnClipRect(int column_index)
{
    ImGuiWindow* window = GetCurrentWindowRead();
    ImGuiOldColumns* columns = window->DC.CurrentColumns;
    if (column_index < 0)
        column_index = columns->Current;

    ImGuiOldColumnData* column = &columns->Columns[column_index];
    PushClipRect(column->ClipRect.Min, column->ClipRect.Max, false);
}

// Get into the columns background draw command (which is generally the same draw command as before we called BeginColumns)
void ImGui::PushColumnsBackground()
{
    ImGuiWindow* window = GetCurrentWindowRead();
    ImGuiOldColumns* columns = window->DC.CurrentColumns;
    if (columns->Count == 1)
        return;

    // Optimization: avoid SetCurrentChannel() + PushClipRect()
    columns->HostBackupClipRect = window->ClipRect;
    SetWindowClipRectBeforeSetChannel(window, columns->HostInitialClipRect);
    columns->Splitter.SetCurrentChannel(window->DrawList, 0);
}

void ImGui::PopColumnsBackground()
{
    ImGuiWindow* window = GetCurrentWindowRead();
    ImGuiOldColumns* columns = window->DC.CurrentColumns;
    if (columns->Count == 1)
        return;

    // Optimization: avoid PopClipRect() + SetCurrentChannel()
    SetWindowClipRectBeforeSetChannel(window, columns->HostBackupClipRect);
    columns->Splitter.SetCurrentChannel(window->DrawList, columns->Current + 1);
}

ImGuiOldColumns* ImGui::FindOrCreateColumns(ImGuiWindow* window, ImGuiID id)
{
    // We have few columns per window so for now we don't need bother much with turning this into a faster lookup.
    for (int n = 0; n < window->ColumnsStorage.Size; n++)
        if (window->ColumnsStorage[n].ID == id)
            return &window->ColumnsStorage[n];

    window->ColumnsStorage.push_back(ImGuiOldColumns());
    ImGuiOldColumns* columns = &window->ColumnsStorage.back();
    columns->ID = id;
    return columns;
}

ImGuiID ImGui::GetColumnsID(const char* str_id, int columns_count)
{
    ImGuiWindow* window = GetCurrentWindow();

    // Differentiate column ID with an arbitrary prefix for cases where users name their columns set the same as another widget.
    // In addition, when an identifier isn't explicitly provided we include the number of columns in the hash to make it uniquer.
    PushID(0x11223347 + (str_id ? 0 : columns_count));
    ImGuiID id = window->GetID(str_id ? str_id : "columns");
    PopID();

    return id;
}

void ImGui::BeginColumns(const char* str_id, int columns_count, ImGuiOldColumnFlags flags)
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = GetCurrentWindow();

    IM_ASSERT(columns_count >= 1);
    IM_ASSERT(window->DC.CurrentColumns == NULL);   // Nested columns are currently not supported

    // Acquire storage for the columns set
    ImGuiID id = GetColumnsID(str_id, columns_count);
    ImGuiOldColumns* columns = FindOrCreateColumns(window, id);
    IM_ASSERT(columns->ID == id);
    columns->Current = 0;
    columns->Count = columns_count;
    columns->Flags = flags;
    window->DC.CurrentColumns = columns;

    columns->HostCursorPosY = window->DC.CursorPos.y;
    columns->HostCursorMaxPosX = window->DC.CursorMaxPos.x;
    columns->HostInitialClipRect = window->ClipRect;
    columns->HostBackupParentWorkRect = window->ParentWorkRect;
    window->ParentWorkRect = window->WorkRect;

    // Set state for first column
    // We aim so that the right-most column will have the same clipping width as other after being clipped by parent ClipRect
    const float column_padding = g.Style.ItemSpacing.x;
    const float half_clip_extend_x = ImFloor(ImMax(window->WindowPadding.x * 0.5f, window->WindowBorderSize));
    const float max_1 = window->WorkRect.Max.x + column_padding - ImMax(column_padding - window->WindowPadding.x, 0.0f);
    const float max_2 = window->WorkRect.Max.x + half_clip_extend_x;
    columns->OffMinX = window->DC.Indent.x - column_padding + ImMax(column_padding - window->WindowPadding.x, 0.0f);
    columns->OffMaxX = ImMax(ImMin(max_1, max_2) - window->Pos.x, columns->OffMinX + 1.0f);
    columns->LineMinY = columns->LineMaxY = window->DC.CursorPos.y;

    // Clear data if columns count changed
    if (columns->Columns.Size != 0 && columns->Columns.Size != columns_count + 1)
        columns->Columns.resize(0);

    // Initialize default widths
    columns->IsFirstFrame = (columns->Columns.Size == 0);
    if (columns->Columns.Size == 0)
    {
        columns->Columns.reserve(columns_count + 1);
        for (int n = 0; n < columns_count + 1; n++)
        {
            ImGuiOldColumnData column;
            column.OffsetNorm = n / (float)columns_count;
            columns->Columns.push_back(column);
        }
    }

    for (int n = 0; n < columns_count; n++)
    {
        // Compute clipping rectangle
        ImGuiOldColumnData* column = &columns->Columns[n];
        float clip_x1 = IM_ROUND(window->Pos.x + GetColumnOffset(n));
        float clip_x2 = IM_ROUND(window->Pos.x + GetColumnOffset(n + 1) - 1.0f);
        column->ClipRect = ImRect(clip_x1, -FLT_MAX, clip_x2, +FLT_MAX);
        column->ClipRect.ClipWithFull(window->ClipRect);
    }

    if (columns->Count > 1)
    {
        columns->Splitter.Split(window->DrawList, 1 + columns->Count);
        columns->Splitter.SetCurrentChannel(window->DrawList, 1);
        PushColumnClipRect(0);
    }

    // We don't generally store Indent.x inside ColumnsOffset because it may be manipulated by the user.
    float offset_0 = GetColumnOffset(columns->Current);
    float offset_1 = GetColumnOffset(columns->Current + 1);
    float width = offset_1 - offset_0;
    PushItemWidth(width * 0.65f);
    window->DC.ColumnsOffset.x = ImMax(column_padding - window->WindowPadding.x, 0.0f);
    window->DC.CursorPos.x = IM_FLOOR(window->Pos.x + window->DC.Indent.x + window->DC.ColumnsOffset.x);
    window->WorkRect.Max.x = window->Pos.x + offset_1 - column_padding;
}

void ImGui::NextColumn()
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems || window->DC.CurrentColumns == NULL)
        return;

    ImGuiContext& g = *GImGui;
    ImGuiOldColumns* columns = window->DC.CurrentColumns;

    if (columns->Count == 1)
    {
        window->DC.CursorPos.x = IM_FLOOR(window->Pos.x + window->DC.Indent.x + window->DC.ColumnsOffset.x);
        IM_ASSERT(columns->Current == 0);
        return;
    }

    // Next column
    if (++columns->Current == columns->Count)
        columns->Current = 0;

    PopItemWidth();

    // Optimization: avoid PopClipRect() + SetCurrentChannel() + PushClipRect()
    // (which would needlessly attempt to update commands in the wrong channel, then pop or overwrite them),
    ImGuiOldColumnData* column = &columns->Columns[columns->Current];
    SetWindowClipRectBeforeSetChannel(window, column->ClipRect);
    columns->Splitter.SetCurrentChannel(window->DrawList, columns->Current + 1);

    const float column_padding = g.Style.ItemSpacing.x;
    columns->LineMaxY = ImMax(columns->LineMaxY, window->DC.CursorPos.y);
    if (columns->Current > 0)
    {
        // Columns 1+ ignore IndentX (by canceling it out)
        // FIXME-COLUMNS: Unnecessary, could be locked?
        window->DC.ColumnsOffset.x = GetColumnOffset(columns->Current) - window->DC.Indent.x + column_padding;
    }
    else
    {
        // New row/line: column 0 honor IndentX.
        window->DC.ColumnsOffset.x = ImMax(column_padding - window->WindowPadding.x, 0.0f);
        columns->LineMinY = columns->LineMaxY;
    }
    window->DC.CursorPos.x = IM_FLOOR(window->Pos.x + window->DC.Indent.x + window->DC.ColumnsOffset.x);
    window->DC.CursorPos.y = columns->LineMinY;
    window->DC.CurrLineSize = ImVec2(0.0f, 0.0f);
    window->DC.CurrLineTextBaseOffset = 0.0f;

    // FIXME-COLUMNS: Share code with BeginColumns() - move code on columns setup.
    float offset_0 = GetColumnOffset(columns->Current);
    float offset_1 = GetColumnOffset(columns->Current + 1);
    float width = offset_1 - offset_0;
    PushItemWidth(width * 0.65f);
    window->WorkRect.Max.x = window->Pos.x + offset_1 - column_padding;
}

void ImGui::EndColumns()
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = GetCurrentWindow();
    ImGuiOldColumns* columns = window->DC.CurrentColumns;
    IM_ASSERT(columns != NULL);

    PopItemWidth();
    if (columns->Count > 1)
    {
        PopClipRect();
        columns->Splitter.Merge(window->DrawList);
    }

    const ImGuiOldColumnFlags flags = columns->Flags;
    columns->LineMaxY = ImMax(columns->LineMaxY, window->DC.CursorPos.y);
    window->DC.CursorPos.y = columns->LineMaxY;
    if (!(flags & ImGuiOldColumnFlags_GrowParentContentsSize))
        window->DC.CursorMaxPos.x = columns->HostCursorMaxPosX;  // Restore cursor max pos, as columns don't grow parent

    // Draw columns borders and handle resize
    // The IsBeingResized flag ensure we preserve pre-resize columns width so back-and-forth are not lossy
    bool is_being_resized = false;
    if (!(flags & ImGuiOldColumnFlags_NoBorder) && !window->SkipItems)
    {
        // We clip Y boundaries CPU side because very long triangles are mishandled by some GPU drivers.
        const float y1 = ImMax(columns->HostCursorPosY, window->ClipRect.Min.y);
        const float y2 = ImMin(window->DC.CursorPos.y, window->ClipRect.Max.y);
        int dragging_column = -1;
        for (int n = 1; n < columns->Count; n++)
        {
            ImGuiOldColumnData* column = &columns->Columns[n];
            float x = window->Pos.x + GetColumnOffset(n);
            const ImGuiID column_id = columns->ID + ImGuiID(n);
            const float column_hit_hw = COLUMNS_HIT_RECT_HALF_WIDTH;
            const ImRect column_hit_rect(ImVec2(x - column_hit_hw, y1), ImVec2(x + column_hit_hw, y2));
            KeepAliveID(column_id);
            if (IsClippedEx(column_hit_rect, column_id, false))
                continue;

            bool hovered = false, held = false;
            if (!(flags & ImGuiOldColumnFlags_NoResize))
            {
                ButtonBehavior(column_hit_rect, column_id, &hovered, &held);
                if (hovered || held)
                    g.MouseCursor = ImGuiMouseCursor_ResizeEW;
                if (held && !(column->Flags & ImGuiOldColumnFlags_NoResize))
                    dragging_column = n;
            }

            // Draw column
            const ImU32 col = GetColorU32(held ? ImGuiCol_SeparatorActive : hovered ? ImGuiCol_SeparatorHovered : ImGuiCol_Separator);
            const float xi = IM_FLOOR(x);
            window->DrawList->AddLine(ImVec2(xi, y1 + 1.0f), ImVec2(xi, y2), col);
        }

        // Apply dragging after drawing the column lines, so our rendered lines are in sync with how items were displayed during the frame.
        if (dragging_column != -1)
        {
            if (!columns->IsBeingResized)
                for (int n = 0; n < columns->Count + 1; n++)
                    columns->Columns[n].OffsetNormBeforeResize = columns->Columns[n].OffsetNorm;
            columns->IsBeingResized = is_being_resized = true;
            float x = GetDraggedColumnOffset(columns, dragging_column);
            SetColumnOffset(dragging_column, x);
        }
    }
    columns->IsBeingResized = is_being_resized;

    window->WorkRect = window->ParentWorkRect;
    window->ParentWorkRect = columns->HostBackupParentWorkRect;
    window->DC.CurrentColumns = NULL;
    window->DC.ColumnsOffset.x = 0.0f;
    window->DC.CursorPos.x = IM_FLOOR(window->Pos.x + window->DC.Indent.x + window->DC.ColumnsOffset.x);
}

void ImGui::Columns(int columns_count, const char* id, bool border)
{
    ImGuiWindow* window = GetCurrentWindow();
    IM_ASSERT(columns_count >= 1);

    ImGuiOldColumnFlags flags = (border ? 0 : ImGuiOldColumnFlags_NoBorder);
    //flags |= ImGuiOldColumnFlags_NoPreserveWidths; // NB: Legacy behavior
    ImGuiOldColumns* columns = window->DC.CurrentColumns;
    if (columns != NULL && columns->Count == columns_count && columns->Flags == flags)
        return;

    if (columns != NULL)
        EndColumns();

    if (columns_count != 1)
        BeginColumns(id, columns_count, flags);
}


//-------------------------------------------------------------------------

#endif // #ifndef IMGUI_DISABLE