Internals: Added ImChunkStream, used by window settings. (more generic followup to 4c13807, the class will be used more extensively by Tables)
diff --git a/imgui.cpp b/imgui.cpp
index c75eb17..c15121a 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -2525,7 +2525,7 @@
LastTimeActive = -1.0f;
ItemWidthDefault = 0.0f;
FontWindowScale = 1.0f;
- SettingsIdx = -1;
+ SettingsOffset = -1;
DrawList = &DrawListInst;
DrawList->_OwnerName = Name;
@@ -3818,7 +3818,6 @@
g.PrivateClipboard.clear();
g.InputTextState.ClearFreeMemory();
- g.SettingsWindowsNames.clear();
g.SettingsWindows.clear();
g.SettingsHandlers.clear();
@@ -4704,7 +4703,7 @@
if (ImGuiWindowSettings* settings = ImGui::FindWindowSettings(window->ID))
{
// Retrieve settings from .ini file
- window->SettingsIdx = g.SettingsWindows.index_from_ptr(settings);
+ window->SettingsOffset = g.SettingsWindows.offset_from_ptr(settings);
SetWindowConditionAllowFlags(window, ImGuiCond_FirstUseEver, false);
window->Pos = ImVec2(settings->Pos.x, settings->Pos.y);
window->Collapsed = settings->Collapsed;
@@ -9205,27 +9204,31 @@
ImGuiWindowSettings* ImGui::CreateNewWindowSettings(const char* name)
{
ImGuiContext& g = *GImGui;
- g.SettingsWindows.push_back(ImGuiWindowSettings());
- ImGuiWindowSettings* settings = &g.SettingsWindows.back();
+
#if !IMGUI_DEBUG_INI_SETTINGS
// Skip to the "###" marker if any. We don't skip past to match the behavior of GetID()
// Preserve the full string when IMGUI_DEBUG_INI_SETTINGS is set to make .ini inspection easier.
if (const char* p = strstr(name, "###"))
name = p;
#endif
- size_t name_len = strlen(name);
- settings->NameOffset = g.SettingsWindowsNames.size();
- g.SettingsWindowsNames.append(name, name + name_len + 1); // Append with zero terminator
+ const size_t name_len = strlen(name);
+
+ // Allocate chunk
+ const size_t chunk_size = sizeof(ImGuiWindowSettings) + name_len + 1;
+ ImGuiWindowSettings* settings = g.SettingsWindows.alloc_chunk(chunk_size);
+ IM_PLACEMENT_NEW(settings) ImGuiWindowSettings();
settings->ID = ImHashStr(name, name_len);
+ memcpy(settings->GetName(), name, name_len + 1); // Store with zero terminator
+
return settings;
}
ImGuiWindowSettings* ImGui::FindWindowSettings(ImGuiID id)
{
ImGuiContext& g = *GImGui;
- for (int i = 0; i != g.SettingsWindows.Size; i++)
- if (g.SettingsWindows[i].ID == id)
- return &g.SettingsWindows[i];
+ for (ImGuiWindowSettings* settings = g.SettingsWindows.begin(); settings != NULL; settings = g.SettingsWindows.next_chunk(settings))
+ if (settings->ID == id)
+ return settings;
return NULL;
}
@@ -9380,11 +9383,11 @@
if (window->Flags & ImGuiWindowFlags_NoSavedSettings)
continue;
- ImGuiWindowSettings* settings = (window->SettingsIdx != -1) ? &g.SettingsWindows[window->SettingsIdx] : ImGui::FindWindowSettings(window->ID);
+ ImGuiWindowSettings* settings = (window->SettingsOffset != -1) ? g.SettingsWindows.ptr_from_offset(window->SettingsOffset) : ImGui::FindWindowSettings(window->ID);
if (!settings)
{
settings = ImGui::CreateNewWindowSettings(window->Name);
- window->SettingsIdx = g.SettingsWindows.index_from_ptr(settings);
+ window->SettingsOffset = g.SettingsWindows.offset_from_ptr(settings);
}
IM_ASSERT(settings->ID == window->ID);
settings->Pos = ImVec2ih((short)window->Pos.x, (short)window->Pos.y);
@@ -9393,11 +9396,10 @@
}
// Write to text buffer
- buf->reserve(buf->size() + g.SettingsWindows.Size * 96); // ballpark reserve
- for (int i = 0; i != g.SettingsWindows.Size; i++)
+ buf->reserve(buf->size() + g.SettingsWindows.size() * 6); // ballpark reserve
+ for (ImGuiWindowSettings* settings = g.SettingsWindows.begin(); settings != NULL; settings = g.SettingsWindows.next_chunk(settings))
{
- const ImGuiWindowSettings* settings = &g.SettingsWindows[i];
- const char* settings_name = g.SettingsWindowsNames.c_str() + settings->NameOffset;
+ const char* settings_name = settings->GetName();
buf->appendf("[%s][%s]\n", handler->TypeName, settings_name);
buf->appendf("Pos=%d,%d\n", settings->Pos.x, settings->Pos.y);
buf->appendf("Size=%d,%d\n", settings->Size.x, settings->Size.y);
diff --git a/imgui_internal.h b/imgui_internal.h
index 6fe74a0..37d4602 100644
--- a/imgui_internal.h
+++ b/imgui_internal.h
@@ -88,7 +88,6 @@
struct ImGuiWindow; // Storage for one window
struct ImGuiWindowTempData; // Temporary storage for one window (that's the data which in theory we could ditch at the end of the frame)
struct ImGuiWindowSettings; // Storage for a window .ini settings (we keep one of those even if the actual window wasn't instanced during this session)
-template<typename T> struct ImPool; // Basic keyed storage for contiguous instances, slow/amortized insertion, O(1) indexable, O(Log N) queries by ID
// Use your programming IDE "Go to definition" facility on the names of the center columns to find the actual flags/enum lists.
typedef int ImGuiLayoutType; // -> enum ImGuiLayoutType_ // Enum: Horizontal or vertical
@@ -145,6 +144,7 @@
// - Helpers: Maths
// - Helper: ImBoolVector
// - Helper: ImPool<>
+// - Helper: ImChunkStream<>
//-----------------------------------------------------------------------------
// Macros
@@ -326,6 +326,28 @@
int GetSize() const { return Buf.Size; }
};
+// Helper: ImChunkStream<>
+// Build and iterate a contiguous stream of variable-sized structures.
+// This is used by Settings to store persistent data while reducing allocation count.
+// We store the chunk size first, and align the final size on 4 bytes boundaries (this what the '(X + 3) & ~3' statement is for)
+// The tedious/zealous amount of casting is to avoid -Wcast-align warnings.
+template<typename T>
+struct IMGUI_API ImChunkStream
+{
+ ImVector<char> Buf;
+
+ void clear() { Buf.clear(); }
+ bool empty() const { return Buf.Size == 0; }
+ int size() const { return Buf.Size; }
+ T* alloc_chunk(size_t sz) { size_t HDR_SZ = 4; sz = ((HDR_SZ + sz) + 3u) & ~3u; int off = Buf.Size; Buf.resize(off + (int)sz); ((int*)(void*)(Buf.Data + off))[0] = (int)sz; return (T*)(void*)(Buf.Data + off + (int)HDR_SZ); }
+ T* begin() { size_t HDR_SZ = 4; if (!Buf.Data) return NULL; return (T*)(void*)(Buf.Data + HDR_SZ); }
+ T* next_chunk(T* p) { size_t HDR_SZ = 4; IM_ASSERT(p >= begin() && p < end()); p = (T*)(void*)((char*)(void*)p + chunk_size(p)); if (p == (T*)(void*)((char*)end() + HDR_SZ)) return (T*)0; IM_ASSERT(p < end()); return p; }
+ int chunk_size(const T* p) { return ((const int*)p)[-1]; }
+ T* end() { return (T*)(void*)(Buf.Data + Buf.Size); }
+ int offset_from_ptr(const T* p) { IM_ASSERT(p >= begin() && p < end()); const ptrdiff_t off = (const char*)p - Buf.Data; return (int)off; }
+ T* ptr_from_offset(int off) { IM_ASSERT(off >= 4 && off < Buf.Size); return (T*)(void*)(Buf.Data + off); }
+};
+
//-----------------------------------------------------------------------------
// Misc data structures
//-----------------------------------------------------------------------------
@@ -681,15 +703,16 @@
// Windows data saved in imgui.ini file
// Because we never destroy or rename ImGuiWindowSettings, we can store the names in a separate buffer easily.
+// (this is designed to be stored in a ImChunkStream buffer, with the variable-length Name following our structure)
struct ImGuiWindowSettings
{
- int NameOffset; // Offset into SettingsWindowNames[]
ImGuiID ID;
ImVec2ih Pos;
ImVec2ih Size;
bool Collapsed;
- ImGuiWindowSettings() { NameOffset = -1; ID = 0; Pos = Size = ImVec2ih(0, 0); Collapsed = false; }
+ ImGuiWindowSettings() { ID = 0; Pos = Size = ImVec2ih(0, 0); Collapsed = false; }
+ char* GetName() { return (char*)(this + 1); }
};
struct ImGuiSettingsHandler
@@ -1053,12 +1076,11 @@
ImVec2 PlatformImeLastPos;
// Settings
- bool SettingsLoaded;
- float SettingsDirtyTimer; // Save .ini Settings to memory when time reaches zero
- ImGuiTextBuffer SettingsIniData; // In memory .ini settings
- ImVector<ImGuiSettingsHandler> SettingsHandlers; // List of .ini settings handlers
- ImVector<ImGuiWindowSettings> SettingsWindows; // ImGuiWindow .ini settings entries (parsed from the last loaded .ini file and maintained on saving)
- ImGuiTextBuffer SettingsWindowsNames; // Names for SettingsWindows
+ bool SettingsLoaded;
+ float SettingsDirtyTimer; // Save .ini Settings to memory when time reaches zero
+ ImGuiTextBuffer SettingsIniData; // In memory .ini settings
+ ImVector<ImGuiSettingsHandler> SettingsHandlers; // List of .ini settings handlers
+ ImChunkStream<ImGuiWindowSettings> SettingsWindows; // ImGuiWindow .ini settings entries
// Logging
bool LogEnabled;
@@ -1369,7 +1391,7 @@
ImGuiStorage StateStorage;
ImVector<ImGuiColumns> ColumnsStorage;
float FontWindowScale; // User scale multiplier per-window, via SetWindowFontScale()
- int SettingsIdx; // Index into SettingsWindow[] (indices are always valid as we only grow the array from the back)
+ int SettingsOffset; // Offset into SettingsWindows[] (offsets are always valid as we only grow the array from the back)
ImDrawList* DrawList; // == &DrawListInst (for backward compatibility reason with code using imgui_internal.h we keep this a pointer)
ImDrawList DrawListInst;
