blob: c079a2b50cc7ac1310c47ce998ea9e59a856c739 [file] [log] [blame]
// dear imgui: Platform Backend for Windows (standard windows API for 32-bits AND 64-bits applications)
// This needs to be used along with a Renderer (e.g. DirectX11, OpenGL3, Vulkan..)
// Implemented features:
// [X] Platform: Clipboard support (for Win32 this is actually part of core dear imgui)
// [X] Platform: Mouse support. Can discriminate Mouse/TouchScreen/Pen.
// [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy VK_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
// [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
// [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
// [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
// Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
// Learn about Dear ImGui:
// - FAQ
// - Getting Started
// - Documentation (same as your local docs/ folder).
// - Introduction, links and more at the top of imgui.cpp
// Configuration flags to add in your imconfig file:
//#define IMGUI_IMPL_WIN32_DISABLE_GAMEPAD // Disable gamepad support. This was meaningful before <1.81 but we now load XInput dynamically so the option is now less relevant.
// (minor and older changes stripped away, please see git history for details)
// 2024-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
// 2023-10-05: Inputs: Added support for extra ImGuiKey values: F13 to F24 function keys, app back/forward keys.
// 2023-09-25: Inputs: Synthesize key-down event on key-up for VK_SNAPSHOT / ImGuiKey_PrintScreen as Windows doesn't emit it (same behavior as GLFW/SDL).
// 2023-09-07: Inputs: Added support for keyboard codepage conversion for when application is compiled in MBCS mode and using a non-Unicode window.
// 2023-04-19: Added ImGui_ImplWin32_InitForOpenGL() to facilitate combining raw Win32/Winapi with OpenGL. (#3218)
// 2023-04-04: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_TouchScreen/ImGuiMouseSource_Pen. (#2702)
// 2023-02-15: Inputs: Use WM_NCMOUSEMOVE / WM_NCMOUSELEAVE to track mouse position over non-client area (e.g. OS decorations) when app is not focused. (#6045, #6162)
// 2023-02-02: Inputs: Flipping WM_MOUSEHWHEEL (horizontal mouse-wheel) value to match other backends and offer consistent horizontal scrolling direction. (#4019, #6096, #1463)
// 2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
// 2022-09-28: Inputs: Convert WM_CHAR values with MultiByteToWideChar() when window class was registered as MBCS (not Unicode).
// 2022-09-26: Inputs: Renamed ImGuiKey_ModXXX introduced in 1.87 to ImGuiMod_XXX (old names still supported).
// 2022-01-26: Inputs: replaced short-lived io.AddKeyModsEvent() (added two weeks ago) with io.AddKeyEvent() using ImGuiKey_ModXXX flags. Sorry for the confusion.
// 2021-01-20: Inputs: calling new io.AddKeyAnalogEvent() for gamepad support, instead of writing directly to io.NavInputs[].
// 2022-01-17: Inputs: calling new io.AddMousePosEvent(), io.AddMouseButtonEvent(), io.AddMouseWheelEvent() API (1.87+).
// 2022-01-17: Inputs: always update key mods next and before a key event (not in NewFrame) to fix input queue with very low framerates.
// 2022-01-12: Inputs: Update mouse inputs using WM_MOUSEMOVE/WM_MOUSELEAVE + fallback to provide it when focused but not hovered/captured. More standard and will allow us to pass it to future input queue API.
// 2022-01-12: Inputs: Maintain our own copy of MouseButtonsDown mask instead of using ImGui::IsAnyMouseDown() which will be obsoleted.
// 2022-01-10: Inputs: calling new io.AddKeyEvent(), io.AddKeyModsEvent() + io.SetKeyEventNativeData() API (1.87+). Support for full ImGuiKey range.
// 2021-12-16: Inputs: Fill VK_LCONTROL/VK_RCONTROL/VK_LSHIFT/VK_RSHIFT/VK_LMENU/VK_RMENU for completeness.
// 2021-08-17: Calling io.AddFocusEvent() on WM_SETFOCUS/WM_KILLFOCUS messages.
// 2021-08-02: Inputs: Fixed keyboard modifiers being reported when host window doesn't have focus.
// 2021-07-29: Inputs: MousePos is correctly reported when the host platform window is hovered but not focused (using TrackMouseEvent() to receive WM_MOUSELEAVE events).
// 2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
// 2021-06-08: Fixed ImGui_ImplWin32_EnableDpiAwareness() and ImGui_ImplWin32_GetDpiScaleForMonitor() to handle Windows 8.1/10 features without a manifest (per-monitor DPI, and properly calls SetProcessDpiAwareness() on 8.1).
// 2021-03-23: Inputs: Clearing keyboard down array when losing focus (WM_KILLFOCUS).
// 2021-02-18: Added ImGui_ImplWin32_EnableAlphaCompositing(). Non Visual Studio users will need to link with dwmapi.lib (MinGW/gcc: use -ldwmapi).
// 2021-02-17: Fixed ImGui_ImplWin32_EnableDpiAwareness() attempting to get SetProcessDpiAwareness from shcore.dll on Windows 8 whereas it is only supported on Windows 8.1.
// 2021-01-25: Inputs: Dynamically loading XInput DLL.
// 2020-12-04: Misc: Fixed setting of io.DisplaySize to invalid/uninitialized data when after hwnd has been closed.
// 2020-03-03: Inputs: Calling AddInputCharacterUTF16() to support surrogate pairs leading to codepoint >= 0x10000 (for more complete CJK inputs)
// 2020-02-17: Added ImGui_ImplWin32_EnableDpiAwareness(), ImGui_ImplWin32_GetDpiScaleForHwnd(), ImGui_ImplWin32_GetDpiScaleForMonitor() helper functions.
// 2020-01-14: Inputs: Added support for #define IMGUI_IMPL_WIN32_DISABLE_GAMEPAD/IMGUI_IMPL_WIN32_DISABLE_LINKING_XINPUT.
// 2019-12-05: Inputs: Added support for ImGuiMouseCursor_NotAllowed mouse cursor.
// 2019-05-11: Inputs: Don't filter value from WM_CHAR before calling AddInputCharacter().
// 2019-01-17: Misc: Using GetForegroundWindow()+IsChild() instead of GetActiveWindow() to be compatible with windows created in a different thread or parent.
// 2019-01-17: Inputs: Added support for mouse buttons 4 and 5 via WM_XBUTTON* messages.
// 2019-01-15: Inputs: Added support for XInput gamepads (if ImGuiConfigFlags_NavEnableGamepad is set by user application).
// 2018-11-30: Misc: Setting up io.BackendPlatformName so it can be displayed in the About Window.
// 2018-06-29: Inputs: Added support for the ImGuiMouseCursor_Hand cursor.
// 2018-06-10: Inputs: Fixed handling of mouse wheel messages to support fine position messages (typically sent by track-pads).
// 2018-06-08: Misc: Extracted imgui_impl_win32.cpp/.h away from the old combined DX9/DX10/DX11/DX12 examples.
// 2018-03-20: Misc: Setup io.BackendFlags ImGuiBackendFlags_HasMouseCursors and ImGuiBackendFlags_HasSetMousePos flags + honor ImGuiConfigFlags_NoMouseCursorChange flag.
// 2018-02-20: Inputs: Added support for mouse cursors (ImGui::GetMouseCursor() value and WM_SETCURSOR message handling).
// 2018-02-06: Inputs: Added mapping for ImGuiKey_Space.
// 2018-02-06: Inputs: Honoring the io.WantSetMousePos by repositioning the mouse (when using navigation and ImGuiConfigFlags_NavMoveMouse is set).
// 2018-02-06: Misc: Removed call to ImGui::Shutdown() which is not available from 1.60 WIP, user needs to call CreateContext/DestroyContext themselves.
// 2018-01-20: Inputs: Added Horizontal Mouse Wheel support.
// 2018-01-08: Inputs: Added mapping for ImGuiKey_Insert.
// 2018-01-05: Inputs: Added WM_LBUTTONDBLCLK double-click handlers for window classes with the CS_DBLCLKS flag.
// 2017-10-23: Inputs: Added WM_SYSKEYDOWN / WM_SYSKEYUP handlers so e.g. the VK_MENU key can be read.
// 2017-10-23: Inputs: Using Win32 ::SetCapture/::GetCapture() to retrieve mouse positions outside the client area when dragging.
// 2016-11-12: Inputs: Only call Win32 ::SetCursor(nullptr) when io.MouseDrawCursor is set.
#include "imgui.h"
#include "imgui_impl_win32.h"
#include <windows.h>
#include <windowsx.h> // GET_X_LPARAM(), GET_Y_LPARAM()
#include <tchar.h>
#include <dwmapi.h>
// Using XInput for gamepad (will load DLL dynamically)
#include <xinput.h>
// Clang/GCC warnings with -Weverything
#if defined(__clang__)
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wcast-function-type" // warning: cast between incompatible function types (for loader)
#if defined(__GNUC__)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wcast-function-type" // warning: cast between incompatible function types (for loader)
// Forward Declarations
static void ImGui_ImplWin32_InitPlatformInterface(bool platform_has_own_dc);
static void ImGui_ImplWin32_ShutdownPlatformInterface();
static void ImGui_ImplWin32_UpdateMonitors();
struct ImGui_ImplWin32_Data
HWND hWnd;
HWND MouseHwnd;
int MouseTrackedArea; // 0: not tracked, 1: client are, 2: non-client area
int MouseButtonsDown;
INT64 Time;
INT64 TicksPerSecond;
ImGuiMouseCursor LastMouseCursor;
UINT32 KeyboardCodePage;
bool WantUpdateMonitors;
bool HasGamepad;
bool WantUpdateHasGamepad;
PFN_XInputGetCapabilities XInputGetCapabilities;
PFN_XInputGetState XInputGetState;
ImGui_ImplWin32_Data() { memset((void*)this, 0, sizeof(*this)); }
// Backend data stored in io.BackendPlatformUserData to allow support for multiple Dear ImGui contexts
// It is STRONGLY preferred that you use docking branch with multi-viewports (== single Dear ImGui context + multiple windows) instead of multiple Dear ImGui contexts.
// FIXME: multi-context support is not well tested and probably dysfunctional in this backend.
// FIXME: some shared resources (mouse cursor shape, gamepad) are mishandled when using multi-context.
static ImGui_ImplWin32_Data* ImGui_ImplWin32_GetBackendData()
return ImGui::GetCurrentContext() ? (ImGui_ImplWin32_Data*)ImGui::GetIO().BackendPlatformUserData : nullptr;
// Functions
static void ImGui_ImplWin32_UpdateKeyboardCodePage()
// Retrieve keyboard code page, required for handling of non-Unicode Windows.
ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
HKL keyboard_layout = ::GetKeyboardLayout(0);
LCID keyboard_lcid = MAKELCID(HIWORD(keyboard_layout), SORT_DEFAULT);
if (::GetLocaleInfoA(keyboard_lcid, (LOCALE_RETURN_NUMBER | LOCALE_IDEFAULTANSICODEPAGE), (LPSTR)&bd->KeyboardCodePage, sizeof(bd->KeyboardCodePage)) == 0)
bd->KeyboardCodePage = CP_ACP; // Fallback to default ANSI code page when fails.
static bool ImGui_ImplWin32_InitEx(void* hwnd, bool platform_has_own_dc)
ImGuiIO& io = ImGui::GetIO();
IM_ASSERT(io.BackendPlatformUserData == nullptr && "Already initialized a platform backend!");
INT64 perf_frequency, perf_counter;
if (!::QueryPerformanceFrequency((LARGE_INTEGER*)&perf_frequency))
return false;
if (!::QueryPerformanceCounter((LARGE_INTEGER*)&perf_counter))
return false;
// Setup backend capabilities flags
ImGui_ImplWin32_Data* bd = IM_NEW(ImGui_ImplWin32_Data)();
io.BackendPlatformUserData = (void*)bd;
io.BackendPlatformName = "imgui_impl_win32";
io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors; // We can honor GetMouseCursor() values (optional)
io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos; // We can honor io.WantSetMousePos requests (optional, rarely used)
io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports; // We can create multi-viewports on the Platform side (optional)
io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport; // We can call io.AddMouseViewportEvent() with correct data (optional)
bd->hWnd = (HWND)hwnd;
bd->WantUpdateMonitors = true;
bd->TicksPerSecond = perf_frequency;
bd->Time = perf_counter;
bd->LastMouseCursor = ImGuiMouseCursor_COUNT;
// Our mouse update function expect PlatformHandle to be filled for the main viewport
ImGuiViewport* main_viewport = ImGui::GetMainViewport();
main_viewport->PlatformHandle = main_viewport->PlatformHandleRaw = (void*)bd->hWnd;
if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
// Dynamically load XInput library
bd->WantUpdateHasGamepad = true;
const char* xinput_dll_names[] =
"xinput1_4.dll", // Windows 8+
"xinput1_3.dll", // DirectX SDK
"xinput9_1_0.dll", // Windows Vista, Windows 7
"xinput1_2.dll", // DirectX SDK
"xinput1_1.dll" // DirectX SDK
for (int n = 0; n < IM_ARRAYSIZE(xinput_dll_names); n++)
if (HMODULE dll = ::LoadLibraryA(xinput_dll_names[n]))
bd->XInputDLL = dll;
bd->XInputGetCapabilities = (PFN_XInputGetCapabilities)::GetProcAddress(dll, "XInputGetCapabilities");
bd->XInputGetState = (PFN_XInputGetState)::GetProcAddress(dll, "XInputGetState");
return true;
IMGUI_IMPL_API bool ImGui_ImplWin32_Init(void* hwnd)
return ImGui_ImplWin32_InitEx(hwnd, false);
IMGUI_IMPL_API bool ImGui_ImplWin32_InitForOpenGL(void* hwnd)
// OpenGL needs CS_OWNDC
return ImGui_ImplWin32_InitEx(hwnd, true);
void ImGui_ImplWin32_Shutdown()
ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
ImGuiIO& io = ImGui::GetIO();
// Unload XInput library
if (bd->XInputDLL)
io.BackendPlatformName = nullptr;
io.BackendPlatformUserData = nullptr;
io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasSetMousePos | ImGuiBackendFlags_HasGamepad | ImGuiBackendFlags_PlatformHasViewports | ImGuiBackendFlags_HasMouseHoveredViewport);
static bool ImGui_ImplWin32_UpdateMouseCursor()
ImGuiIO& io = ImGui::GetIO();
if (io.ConfigFlags & ImGuiConfigFlags_NoMouseCursorChange)
return false;
ImGuiMouseCursor imgui_cursor = ImGui::GetMouseCursor();
if (imgui_cursor == ImGuiMouseCursor_None || io.MouseDrawCursor)
// Hide OS mouse cursor if imgui is drawing it or if it wants no cursor
// Show OS mouse cursor
LPTSTR win32_cursor = IDC_ARROW;
switch (imgui_cursor)
case ImGuiMouseCursor_Arrow: win32_cursor = IDC_ARROW; break;
case ImGuiMouseCursor_TextInput: win32_cursor = IDC_IBEAM; break;
case ImGuiMouseCursor_ResizeAll: win32_cursor = IDC_SIZEALL; break;
case ImGuiMouseCursor_ResizeEW: win32_cursor = IDC_SIZEWE; break;
case ImGuiMouseCursor_ResizeNS: win32_cursor = IDC_SIZENS; break;
case ImGuiMouseCursor_ResizeNESW: win32_cursor = IDC_SIZENESW; break;
case ImGuiMouseCursor_ResizeNWSE: win32_cursor = IDC_SIZENWSE; break;
case ImGuiMouseCursor_Hand: win32_cursor = IDC_HAND; break;
case ImGuiMouseCursor_NotAllowed: win32_cursor = IDC_NO; break;
::SetCursor(::LoadCursor(nullptr, win32_cursor));
return true;
static bool IsVkDown(int vk)
return (::GetKeyState(vk) & 0x8000) != 0;
static void ImGui_ImplWin32_AddKeyEvent(ImGuiKey key, bool down, int native_keycode, int native_scancode = -1)
ImGuiIO& io = ImGui::GetIO();
io.AddKeyEvent(key, down);
io.SetKeyEventNativeData(key, native_keycode, native_scancode); // To support legacy indexing (<1.87 user code)
static void ImGui_ImplWin32_ProcessKeyEventsWorkarounds()
// Left & right Shift keys: when both are pressed together, Windows tend to not generate the WM_KEYUP event for the first released one.
if (ImGui::IsKeyDown(ImGuiKey_LeftShift) && !IsVkDown(VK_LSHIFT))
ImGui_ImplWin32_AddKeyEvent(ImGuiKey_LeftShift, false, VK_LSHIFT);
if (ImGui::IsKeyDown(ImGuiKey_RightShift) && !IsVkDown(VK_RSHIFT))
ImGui_ImplWin32_AddKeyEvent(ImGuiKey_RightShift, false, VK_RSHIFT);
// Sometimes WM_KEYUP for Win key is not passed down to the app (e.g. for Win+V on some setups, according to GLFW).
if (ImGui::IsKeyDown(ImGuiKey_LeftSuper) && !IsVkDown(VK_LWIN))
ImGui_ImplWin32_AddKeyEvent(ImGuiKey_LeftSuper, false, VK_LWIN);
if (ImGui::IsKeyDown(ImGuiKey_RightSuper) && !IsVkDown(VK_RWIN))
ImGui_ImplWin32_AddKeyEvent(ImGuiKey_RightSuper, false, VK_RWIN);
static void ImGui_ImplWin32_UpdateKeyModifiers()
ImGuiIO& io = ImGui::GetIO();
io.AddKeyEvent(ImGuiMod_Ctrl, IsVkDown(VK_CONTROL));
io.AddKeyEvent(ImGuiMod_Shift, IsVkDown(VK_SHIFT));
io.AddKeyEvent(ImGuiMod_Alt, IsVkDown(VK_MENU));
io.AddKeyEvent(ImGuiMod_Super, IsVkDown(VK_APPS));
// This code supports multi-viewports (multiple OS Windows mapped into different Dear ImGui viewports)
// Because of that, it is a little more complicated than your typical single-viewport binding code!
static void ImGui_ImplWin32_UpdateMouseData()
ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
ImGuiIO& io = ImGui::GetIO();
IM_ASSERT(bd->hWnd != 0);
POINT mouse_screen_pos;
bool has_mouse_screen_pos = ::GetCursorPos(&mouse_screen_pos) != 0;
HWND focused_window = ::GetForegroundWindow();
const bool is_app_focused = (focused_window && (focused_window == bd->hWnd || ::IsChild(focused_window, bd->hWnd) || ImGui::FindViewportByPlatformHandle((void*)focused_window)));
if (is_app_focused)
// (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user)
// When multi-viewports are enabled, all Dear ImGui positions are same as OS positions.
if (io.WantSetMousePos)
POINT pos = { (int)io.MousePos.x, (int)io.MousePos.y };
if ((io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable) == 0)
::ClientToScreen(focused_window, &pos);
::SetCursorPos(pos.x, pos.y);
// (Optional) Fallback to provide mouse position when focused (WM_MOUSEMOVE already provides this when hovered or captured)
// This also fills a short gap when clicking non-client area: WM_NCMOUSELEAVE -> modal OS move -> gap -> WM_NCMOUSEMOVE
if (!io.WantSetMousePos && bd->MouseTrackedArea == 0 && has_mouse_screen_pos)
// Single viewport mode: mouse position in client window coordinates (io.MousePos is (0,0) when the mouse is on the upper-left corner of the app window)
// (This is the position you can get with ::GetCursorPos() + ::ScreenToClient() or WM_MOUSEMOVE.)
// Multi-viewport mode: mouse position in OS absolute coordinates (io.MousePos is (0,0) when the mouse is on the upper-left of the primary monitor)
// (This is the position you can get with ::GetCursorPos() or WM_MOUSEMOVE + ::ClientToScreen(). In theory adding viewport->Pos to a client position would also be the same.)
POINT mouse_pos = mouse_screen_pos;
if (!(io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable))
::ScreenToClient(bd->hWnd, &mouse_pos);
io.AddMousePosEvent((float)mouse_pos.x, (float)mouse_pos.y);
// (Optional) When using multiple viewports: call io.AddMouseViewportEvent() with the viewport the OS mouse cursor is hovering.
// If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
// - [X] Win32 backend correctly ignore viewports with the _NoInputs flag (here using ::WindowFromPoint with WM_NCHITTEST + HTTRANSPARENT in WndProc does that)
// Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
// for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
// by the backend, and use its flawed heuristic to guess the viewport behind.
// - [X] Win32 backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
ImGuiID mouse_viewport_id = 0;
if (has_mouse_screen_pos)
if (HWND hovered_hwnd = ::WindowFromPoint(mouse_screen_pos))
if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle((void*)hovered_hwnd))
mouse_viewport_id = viewport->ID;
// Gamepad navigation mapping
static void ImGui_ImplWin32_UpdateGamepads()
ImGuiIO& io = ImGui::GetIO();
ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
//if ((io.ConfigFlags & ImGuiConfigFlags_NavEnableGamepad) == 0) // FIXME: Technically feeding gamepad shouldn't depend on this now that they are regular inputs.
// return;
// Calling XInputGetState() every frame on disconnected gamepads is unfortunately too slow.
// Instead we refresh gamepad availability by calling XInputGetCapabilities() _only_ after receiving WM_DEVICECHANGE.
if (bd->WantUpdateHasGamepad)
bd->HasGamepad = bd->XInputGetCapabilities ? (bd->XInputGetCapabilities(0, XINPUT_FLAG_GAMEPAD, &caps) == ERROR_SUCCESS) : false;
bd->WantUpdateHasGamepad = false;
io.BackendFlags &= ~ImGuiBackendFlags_HasGamepad;
XINPUT_STATE xinput_state;
XINPUT_GAMEPAD& gamepad = xinput_state.Gamepad;
if (!bd->HasGamepad || bd->XInputGetState == nullptr || bd->XInputGetState(0, &xinput_state) != ERROR_SUCCESS)
io.BackendFlags |= ImGuiBackendFlags_HasGamepad;
#define IM_SATURATE(V) (V < 0.0f ? 0.0f : V > 1.0f ? 1.0f : V)
#define MAP_BUTTON(KEY_NO, BUTTON_ENUM) { io.AddKeyEvent(KEY_NO, (gamepad.wButtons & BUTTON_ENUM) != 0); }
#define MAP_ANALOG(KEY_NO, VALUE, V0, V1) { float vn = (float)(VALUE - V0) / (float)(V1 - V0); io.AddKeyAnalogEvent(KEY_NO, vn > 0.10f, IM_SATURATE(vn)); }
MAP_ANALOG(ImGuiKey_GamepadL2, gamepad.bLeftTrigger, XINPUT_GAMEPAD_TRIGGER_THRESHOLD, 255);
MAP_ANALOG(ImGuiKey_GamepadR2, gamepad.bRightTrigger, XINPUT_GAMEPAD_TRIGGER_THRESHOLD, 255);
MAP_ANALOG(ImGuiKey_GamepadLStickLeft, gamepad.sThumbLX, -XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, -32768);
MAP_ANALOG(ImGuiKey_GamepadLStickRight, gamepad.sThumbLX, +XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, +32767);
MAP_ANALOG(ImGuiKey_GamepadLStickUp, gamepad.sThumbLY, +XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, +32767);
MAP_ANALOG(ImGuiKey_GamepadLStickDown, gamepad.sThumbLY, -XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, -32768);
MAP_ANALOG(ImGuiKey_GamepadRStickLeft, gamepad.sThumbRX, -XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, -32768);
MAP_ANALOG(ImGuiKey_GamepadRStickRight, gamepad.sThumbRX, +XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, +32767);
MAP_ANALOG(ImGuiKey_GamepadRStickUp, gamepad.sThumbRY, +XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, +32767);
MAP_ANALOG(ImGuiKey_GamepadRStickDown, gamepad.sThumbRY, -XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, -32768);
static BOOL CALLBACK ImGui_ImplWin32_UpdateMonitors_EnumFunc(HMONITOR monitor, HDC, LPRECT, LPARAM)
MONITORINFO info = {};
info.cbSize = sizeof(MONITORINFO);
if (!::GetMonitorInfo(monitor, &info))
return TRUE;
ImGuiPlatformMonitor imgui_monitor;
imgui_monitor.MainPos = ImVec2((float)info.rcMonitor.left, (float);
imgui_monitor.MainSize = ImVec2((float)(info.rcMonitor.right - info.rcMonitor.left), (float)(info.rcMonitor.bottom -;
imgui_monitor.WorkPos = ImVec2((float)info.rcWork.left, (float);
imgui_monitor.WorkSize = ImVec2((float)(info.rcWork.right - info.rcWork.left), (float)(info.rcWork.bottom -;
imgui_monitor.DpiScale = ImGui_ImplWin32_GetDpiScaleForMonitor(monitor);
imgui_monitor.PlatformHandle = (void*)monitor;
ImGuiPlatformIO& io = ImGui::GetPlatformIO();
if (info.dwFlags & MONITORINFOF_PRIMARY)
return TRUE;
static void ImGui_ImplWin32_UpdateMonitors()
ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
::EnumDisplayMonitors(nullptr, nullptr, ImGui_ImplWin32_UpdateMonitors_EnumFunc, 0);
bd->WantUpdateMonitors = false;
void ImGui_ImplWin32_NewFrame()
ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
IM_ASSERT(bd != nullptr && "Context or backend not initialized? Did you call ImGui_ImplWin32_Init()?");
ImGuiIO& io = ImGui::GetIO();
// Setup display size (every frame to accommodate for window resizing)
RECT rect = { 0, 0, 0, 0 };
::GetClientRect(bd->hWnd, &rect);
io.DisplaySize = ImVec2((float)(rect.right - rect.left), (float)(rect.bottom -;
if (bd->WantUpdateMonitors)
// Setup time step
INT64 current_time = 0;
io.DeltaTime = (float)(current_time - bd->Time) / bd->TicksPerSecond;
bd->Time = current_time;
// Update OS mouse position
// Process workarounds for known Windows key handling issues
// Update OS mouse cursor with the cursor requested by imgui
ImGuiMouseCursor mouse_cursor = io.MouseDrawCursor ? ImGuiMouseCursor_None : ImGui::GetMouseCursor();
if (bd->LastMouseCursor != mouse_cursor)
bd->LastMouseCursor = mouse_cursor;
// Update game controllers (if enabled and available)
// There is no distinct VK_xxx for keypad enter, instead it is VK_RETURN + KF_EXTENDED, we assign it an arbitrary value to make code more readable (VK_ codes go up to 255)
// Map VK_xxx to ImGuiKey_xxx.
static ImGuiKey ImGui_ImplWin32_VirtualKeyToImGuiKey(WPARAM wParam)
switch (wParam)
case VK_TAB: return ImGuiKey_Tab;
case VK_LEFT: return ImGuiKey_LeftArrow;
case VK_RIGHT: return ImGuiKey_RightArrow;
case VK_UP: return ImGuiKey_UpArrow;
case VK_DOWN: return ImGuiKey_DownArrow;
case VK_PRIOR: return ImGuiKey_PageUp;
case VK_NEXT: return ImGuiKey_PageDown;
case VK_HOME: return ImGuiKey_Home;
case VK_END: return ImGuiKey_End;
case VK_INSERT: return ImGuiKey_Insert;
case VK_DELETE: return ImGuiKey_Delete;
case VK_BACK: return ImGuiKey_Backspace;
case VK_SPACE: return ImGuiKey_Space;
case VK_RETURN: return ImGuiKey_Enter;
case VK_ESCAPE: return ImGuiKey_Escape;
case VK_OEM_7: return ImGuiKey_Apostrophe;
case VK_OEM_COMMA: return ImGuiKey_Comma;
case VK_OEM_MINUS: return ImGuiKey_Minus;
case VK_OEM_PERIOD: return ImGuiKey_Period;
case VK_OEM_2: return ImGuiKey_Slash;
case VK_OEM_1: return ImGuiKey_Semicolon;
case VK_OEM_PLUS: return ImGuiKey_Equal;
case VK_OEM_4: return ImGuiKey_LeftBracket;
case VK_OEM_5: return ImGuiKey_Backslash;
case VK_OEM_6: return ImGuiKey_RightBracket;
case VK_OEM_3: return ImGuiKey_GraveAccent;
case VK_CAPITAL: return ImGuiKey_CapsLock;
case VK_SCROLL: return ImGuiKey_ScrollLock;
case VK_NUMLOCK: return ImGuiKey_NumLock;
case VK_SNAPSHOT: return ImGuiKey_PrintScreen;
case VK_PAUSE: return ImGuiKey_Pause;
case VK_NUMPAD0: return ImGuiKey_Keypad0;
case VK_NUMPAD1: return ImGuiKey_Keypad1;
case VK_NUMPAD2: return ImGuiKey_Keypad2;
case VK_NUMPAD3: return ImGuiKey_Keypad3;
case VK_NUMPAD4: return ImGuiKey_Keypad4;
case VK_NUMPAD5: return ImGuiKey_Keypad5;
case VK_NUMPAD6: return ImGuiKey_Keypad6;
case VK_NUMPAD7: return ImGuiKey_Keypad7;
case VK_NUMPAD8: return ImGuiKey_Keypad8;
case VK_NUMPAD9: return ImGuiKey_Keypad9;
case VK_DECIMAL: return ImGuiKey_KeypadDecimal;
case VK_DIVIDE: return ImGuiKey_KeypadDivide;
case VK_MULTIPLY: return ImGuiKey_KeypadMultiply;
case VK_SUBTRACT: return ImGuiKey_KeypadSubtract;
case VK_ADD: return ImGuiKey_KeypadAdd;
case IM_VK_KEYPAD_ENTER: return ImGuiKey_KeypadEnter;
case VK_LSHIFT: return ImGuiKey_LeftShift;
case VK_LCONTROL: return ImGuiKey_LeftCtrl;
case VK_LMENU: return ImGuiKey_LeftAlt;
case VK_LWIN: return ImGuiKey_LeftSuper;
case VK_RSHIFT: return ImGuiKey_RightShift;
case VK_RCONTROL: return ImGuiKey_RightCtrl;
case VK_RMENU: return ImGuiKey_RightAlt;
case VK_RWIN: return ImGuiKey_RightSuper;
case VK_APPS: return ImGuiKey_Menu;
case '0': return ImGuiKey_0;
case '1': return ImGuiKey_1;
case '2': return ImGuiKey_2;
case '3': return ImGuiKey_3;
case '4': return ImGuiKey_4;
case '5': return ImGuiKey_5;
case '6': return ImGuiKey_6;
case '7': return ImGuiKey_7;
case '8': return ImGuiKey_8;
case '9': return ImGuiKey_9;
case 'A': return ImGuiKey_A;
case 'B': return ImGuiKey_B;
case 'C': return ImGuiKey_C;
case 'D': return ImGuiKey_D;
case 'E': return ImGuiKey_E;
case 'F': return ImGuiKey_F;
case 'G': return ImGuiKey_G;
case 'H': return ImGuiKey_H;
case 'I': return ImGuiKey_I;
case 'J': return ImGuiKey_J;
case 'K': return ImGuiKey_K;
case 'L': return ImGuiKey_L;
case 'M': return ImGuiKey_M;
case 'N': return ImGuiKey_N;
case 'O': return ImGuiKey_O;
case 'P': return ImGuiKey_P;
case 'Q': return ImGuiKey_Q;
case 'R': return ImGuiKey_R;
case 'S': return ImGuiKey_S;
case 'T': return ImGuiKey_T;
case 'U': return ImGuiKey_U;
case 'V': return ImGuiKey_V;
case 'W': return ImGuiKey_W;
case 'X': return ImGuiKey_X;
case 'Y': return ImGuiKey_Y;
case 'Z': return ImGuiKey_Z;
case VK_F1: return ImGuiKey_F1;
case VK_F2: return ImGuiKey_F2;
case VK_F3: return ImGuiKey_F3;
case VK_F4: return ImGuiKey_F4;
case VK_F5: return ImGuiKey_F5;
case VK_F6: return ImGuiKey_F6;
case VK_F7: return ImGuiKey_F7;
case VK_F8: return ImGuiKey_F8;
case VK_F9: return ImGuiKey_F9;
case VK_F10: return ImGuiKey_F10;
case VK_F11: return ImGuiKey_F11;
case VK_F12: return ImGuiKey_F12;
case VK_F13: return ImGuiKey_F13;
case VK_F14: return ImGuiKey_F14;
case VK_F15: return ImGuiKey_F15;
case VK_F16: return ImGuiKey_F16;
case VK_F17: return ImGuiKey_F17;
case VK_F18: return ImGuiKey_F18;
case VK_F19: return ImGuiKey_F19;
case VK_F20: return ImGuiKey_F20;
case VK_F21: return ImGuiKey_F21;
case VK_F22: return ImGuiKey_F22;
case VK_F23: return ImGuiKey_F23;
case VK_F24: return ImGuiKey_F24;
case VK_BROWSER_BACK: return ImGuiKey_AppBack;
case VK_BROWSER_FORWARD: return ImGuiKey_AppForward;
default: return ImGuiKey_None;
// Allow compilation with old Windows SDK. MinGW doesn't have default _WIN32_WINNT/WINVER versions.
#define WM_MOUSEHWHEEL 0x020E
// Win32 message handler (process Win32 mouse/keyboard inputs, etc.)
// Call from your application's message handler. Keep calling your message handler unless this function returns TRUE.
// When implementing your own backend, you can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if Dear ImGui wants to use your inputs.
// - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
// - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
// Generally you may always pass all inputs to Dear ImGui, and hide them from your application based on those two flags.
// PS: In this Win32 handler, we use the capture API (GetCapture/SetCapture/ReleaseCapture) to be able to read mouse coordinates when dragging mouse outside of our window bounds.
// PS: We treat DBLCLK messages as regular mouse down messages, so this code will work on windows classes that have the CS_DBLCLKS flag set. Our own example app code doesn't set this flag.
#if 0
// Copy this line into your .cpp file to forward declare the function.
extern IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
// See
// Prefer to call this at the top of the message handler to avoid the possibility of other Win32 calls interfering with this.
static ImGuiMouseSource GetMouseSourceFromMessageExtraInfo()
LPARAM extra_info = ::GetMessageExtraInfo();
if ((extra_info & 0xFFFFFF80) == 0xFF515700)
return ImGuiMouseSource_Pen;
if ((extra_info & 0xFFFFFF80) == 0xFF515780)
return ImGuiMouseSource_TouchScreen;
return ImGuiMouseSource_Mouse;
IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
// Most backends don't have silent checks like this one, but we need it because WndProc are called early in CreateWindow().
// We silently allow both context or just only backend data to be nullptr.
ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
if (bd == nullptr)
return 0;
ImGuiIO& io = ImGui::GetIO();
switch (msg)
// We need to call TrackMouseEvent in order to receive WM_MOUSELEAVE events
ImGuiMouseSource mouse_source = GetMouseSourceFromMessageExtraInfo();
const int area = (msg == WM_MOUSEMOVE) ? 1 : 2;
bd->MouseHwnd = hwnd;
if (bd->MouseTrackedArea != area)
TRACKMOUSEEVENT tme_cancel = { sizeof(tme_cancel), TME_CANCEL, hwnd, 0 };
TRACKMOUSEEVENT tme_track = { sizeof(tme_track), (DWORD)((area == 2) ? (TME_LEAVE | TME_NONCLIENT) : TME_LEAVE), hwnd, 0 };
if (bd->MouseTrackedArea != 0)
bd->MouseTrackedArea = area;
POINT mouse_pos = { (LONG)GET_X_LPARAM(lParam), (LONG)GET_Y_LPARAM(lParam) };
bool want_absolute_pos = (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable) != 0;
if (msg == WM_MOUSEMOVE && want_absolute_pos) // WM_MOUSEMOVE are client-relative coordinates.
::ClientToScreen(hwnd, &mouse_pos);
if (msg == WM_NCMOUSEMOVE && !want_absolute_pos) // WM_NCMOUSEMOVE are absolute coordinates.
::ScreenToClient(hwnd, &mouse_pos);
io.AddMousePosEvent((float)mouse_pos.x, (float)mouse_pos.y);
return 0;
const int area = (msg == WM_MOUSELEAVE) ? 1 : 2;
if (bd->MouseTrackedArea == area)
if (bd->MouseHwnd == hwnd)
bd->MouseHwnd = nullptr;
bd->MouseTrackedArea = 0;
io.AddMousePosEvent(-FLT_MAX, -FLT_MAX);
return 0;
ImGuiMouseSource mouse_source = GetMouseSourceFromMessageExtraInfo();
int button = 0;
if (msg == WM_LBUTTONDOWN || msg == WM_LBUTTONDBLCLK) { button = 0; }
if (msg == WM_RBUTTONDOWN || msg == WM_RBUTTONDBLCLK) { button = 1; }
if (msg == WM_MBUTTONDOWN || msg == WM_MBUTTONDBLCLK) { button = 2; }
if (msg == WM_XBUTTONDOWN || msg == WM_XBUTTONDBLCLK) { button = (GET_XBUTTON_WPARAM(wParam) == XBUTTON1) ? 3 : 4; }
if (bd->MouseButtonsDown == 0 && ::GetCapture() == nullptr)
bd->MouseButtonsDown |= 1 << button;
io.AddMouseButtonEvent(button, true);
return 0;
ImGuiMouseSource mouse_source = GetMouseSourceFromMessageExtraInfo();
int button = 0;
if (msg == WM_LBUTTONUP) { button = 0; }
if (msg == WM_RBUTTONUP) { button = 1; }
if (msg == WM_MBUTTONUP) { button = 2; }
if (msg == WM_XBUTTONUP) { button = (GET_XBUTTON_WPARAM(wParam) == XBUTTON1) ? 3 : 4; }
bd->MouseButtonsDown &= ~(1 << button);
if (bd->MouseButtonsDown == 0 && ::GetCapture() == hwnd)
io.AddMouseButtonEvent(button, false);
return 0;
io.AddMouseWheelEvent(0.0f, (float)GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA);
return 0;
io.AddMouseWheelEvent(-(float)GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA, 0.0f);
return 0;
case WM_KEYUP:
const bool is_key_down = (msg == WM_KEYDOWN || msg == WM_SYSKEYDOWN);
if (wParam < 256)
// Submit modifiers
// Obtain virtual key code
// (keypad enter doesn't have its own... VK_RETURN with KF_EXTENDED flag means keypad enter, see IM_VK_KEYPAD_ENTER definition for details, it is mapped to ImGuiKey_KeyPadEnter.)
int vk = (int)wParam;
if ((wParam == VK_RETURN) && (HIWORD(lParam) & KF_EXTENDED))
const ImGuiKey key = ImGui_ImplWin32_VirtualKeyToImGuiKey(vk);
const int scancode = (int)LOBYTE(HIWORD(lParam));
// Special behavior for VK_SNAPSHOT / ImGuiKey_PrintScreen as Windows doesn't emit the key down event.
if (key == ImGuiKey_PrintScreen && !is_key_down)
ImGui_ImplWin32_AddKeyEvent(key, true, vk, scancode);
// Submit key event
if (key != ImGuiKey_None)
ImGui_ImplWin32_AddKeyEvent(key, is_key_down, vk, scancode);
// Submit individual left/right modifier events
if (vk == VK_SHIFT)
// Important: Shift keys tend to get stuck when pressed together, missing key-up events are corrected in ImGui_ImplWin32_ProcessKeyEventsWorkarounds()
if (IsVkDown(VK_LSHIFT) == is_key_down) { ImGui_ImplWin32_AddKeyEvent(ImGuiKey_LeftShift, is_key_down, VK_LSHIFT, scancode); }
if (IsVkDown(VK_RSHIFT) == is_key_down) { ImGui_ImplWin32_AddKeyEvent(ImGuiKey_RightShift, is_key_down, VK_RSHIFT, scancode); }
else if (vk == VK_CONTROL)
if (IsVkDown(VK_LCONTROL) == is_key_down) { ImGui_ImplWin32_AddKeyEvent(ImGuiKey_LeftCtrl, is_key_down, VK_LCONTROL, scancode); }
if (IsVkDown(VK_RCONTROL) == is_key_down) { ImGui_ImplWin32_AddKeyEvent(ImGuiKey_RightCtrl, is_key_down, VK_RCONTROL, scancode); }
else if (vk == VK_MENU)
if (IsVkDown(VK_LMENU) == is_key_down) { ImGui_ImplWin32_AddKeyEvent(ImGuiKey_LeftAlt, is_key_down, VK_LMENU, scancode); }
if (IsVkDown(VK_RMENU) == is_key_down) { ImGui_ImplWin32_AddKeyEvent(ImGuiKey_RightAlt, is_key_down, VK_RMENU, scancode); }
return 0;
io.AddFocusEvent(msg == WM_SETFOCUS);
return 0;
return 0;
case WM_CHAR:
if (::IsWindowUnicode(hwnd))
// You can also use ToAscii()+GetKeyboardState() to retrieve characters.
if (wParam > 0 && wParam < 0x10000)
io.AddInputCharacterUTF16((unsigned short)wParam);
wchar_t wch = 0;
::MultiByteToWideChar(bd->KeyboardCodePage, MB_PRECOMPOSED, (char*)&wParam, 1, &wch, 1);
return 0;
// This is required to restore cursor when transitioning from e.g resize borders to client area.
if (LOWORD(lParam) == HTCLIENT && ImGui_ImplWin32_UpdateMouseCursor())
return 1;
return 0;
bd->WantUpdateHasGamepad = true;
return 0;
bd->WantUpdateMonitors = true;
return 0;
return 0;
// DPI-related helpers (optional)
// - Use to enable DPI awareness without having to create an application manifest.
// - Your own app may already do this via a manifest or explicit calls. This is mostly useful for our examples/ apps.
// - In theory we could call simple functions from Windows SDK such as SetProcessDPIAware(), SetProcessDpiAwareness(), etc.
// but most of the functions provided by Microsoft require Windows 8.1/10+ SDK at compile time and Windows 8/10+ at runtime,
// neither we want to require the user to have. So we dynamically select and load those functions to avoid dependencies.
// This is the scheme successfully used by GLFW (from which we borrowed some of the code) and other apps aiming to be highly portable.
// ImGui_ImplWin32_EnableDpiAwareness() is just a helper called by main.cpp, we don't call it automatically.
// If you are trying to implement your own backend for your own engine, you may ignore that noise.
// Perform our own check with RtlVerifyVersionInfo() instead of using functions from <VersionHelpers.h> as they
// require a manifest to be functional for checks above 8.1. See
static BOOL _IsWindowsVersionOrGreater(WORD major, WORD minor, WORD)
static PFN_RtlVerifyVersionInfo RtlVerifyVersionInfoFn = nullptr;
if (RtlVerifyVersionInfoFn == nullptr)
if (HMODULE ntdllModule = ::GetModuleHandleA("ntdll.dll"))
RtlVerifyVersionInfoFn = (PFN_RtlVerifyVersionInfo)GetProcAddress(ntdllModule, "RtlVerifyVersionInfo");
if (RtlVerifyVersionInfoFn == nullptr)
return FALSE;
ULONGLONG conditionMask = 0;
versionInfo.dwOSVersionInfoSize = sizeof(RTL_OSVERSIONINFOEXW);
versionInfo.dwMajorVersion = major;
versionInfo.dwMinorVersion = minor;
return (RtlVerifyVersionInfoFn(&versionInfo, VER_MAJORVERSION | VER_MINORVERSION, conditionMask) == 0) ? TRUE : FALSE;
#define _IsWindowsVistaOrGreater() _IsWindowsVersionOrGreater(HIBYTE(0x0600), LOBYTE(0x0600), 0) // _WIN32_WINNT_VISTA
#define _IsWindows8OrGreater() _IsWindowsVersionOrGreater(HIBYTE(0x0602), LOBYTE(0x0602), 0) // _WIN32_WINNT_WIN8
#define _IsWindows8Point1OrGreater() _IsWindowsVersionOrGreater(HIBYTE(0x0603), LOBYTE(0x0603), 0) // _WIN32_WINNT_WINBLUE
#define _IsWindows10OrGreater() _IsWindowsVersionOrGreater(HIBYTE(0x0A00), LOBYTE(0x0A00), 0) // _WIN32_WINNT_WINTHRESHOLD / _WIN32_WINNT_WIN10
typedef HRESULT(WINAPI* PFN_SetProcessDpiAwareness)(PROCESS_DPI_AWARENESS); // Shcore.lib + dll, Windows 8.1+
typedef HRESULT(WINAPI* PFN_GetDpiForMonitor)(HMONITOR, MONITOR_DPI_TYPE, UINT*, UINT*); // Shcore.lib + dll, Windows 8.1+
typedef DPI_AWARENESS_CONTEXT(WINAPI* PFN_SetThreadDpiAwarenessContext)(DPI_AWARENESS_CONTEXT); // User32.lib + dll, Windows 10 v1607+ (Creators Update)
// Helper function to enable DPI awareness without setting up a manifest
void ImGui_ImplWin32_EnableDpiAwareness()
// Make sure monitors will be updated with latest correct scaling
if (ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData())
bd->WantUpdateMonitors = true;
if (_IsWindows10OrGreater())
static HINSTANCE user32_dll = ::LoadLibraryA("user32.dll"); // Reference counted per-process
if (PFN_SetThreadDpiAwarenessContext SetThreadDpiAwarenessContextFn = (PFN_SetThreadDpiAwarenessContext)::GetProcAddress(user32_dll, "SetThreadDpiAwarenessContext"))
if (_IsWindows8Point1OrGreater())
static HINSTANCE shcore_dll = ::LoadLibraryA("shcore.dll"); // Reference counted per-process
if (PFN_SetProcessDpiAwareness SetProcessDpiAwarenessFn = (PFN_SetProcessDpiAwareness)::GetProcAddress(shcore_dll, "SetProcessDpiAwareness"))
#if _WIN32_WINNT >= 0x0600
#if defined(_MSC_VER) && !defined(NOGDI)
#pragma comment(lib, "gdi32") // Link with gdi32.lib for GetDeviceCaps(). MinGW will require linking with '-lgdi32'
float ImGui_ImplWin32_GetDpiScaleForMonitor(void* monitor)
UINT xdpi = 96, ydpi = 96;
if (_IsWindows8Point1OrGreater())
static HINSTANCE shcore_dll = ::LoadLibraryA("shcore.dll"); // Reference counted per-process
static PFN_GetDpiForMonitor GetDpiForMonitorFn = nullptr;
if (GetDpiForMonitorFn == nullptr && shcore_dll != nullptr)
GetDpiForMonitorFn = (PFN_GetDpiForMonitor)::GetProcAddress(shcore_dll, "GetDpiForMonitor");
if (GetDpiForMonitorFn != nullptr)
GetDpiForMonitorFn((HMONITOR)monitor, MDT_EFFECTIVE_DPI, &xdpi, &ydpi);
IM_ASSERT(xdpi == ydpi); // Please contact me if you hit this assert!
return xdpi / 96.0f;
#ifndef NOGDI
const HDC dc = ::GetDC(nullptr);
xdpi = ::GetDeviceCaps(dc, LOGPIXELSX);
ydpi = ::GetDeviceCaps(dc, LOGPIXELSY);
IM_ASSERT(xdpi == ydpi); // Please contact me if you hit this assert!
::ReleaseDC(nullptr, dc);
return xdpi / 96.0f;
float ImGui_ImplWin32_GetDpiScaleForHwnd(void* hwnd)
HMONITOR monitor = ::MonitorFromWindow((HWND)hwnd, MONITOR_DEFAULTTONEAREST);
return ImGui_ImplWin32_GetDpiScaleForMonitor(monitor);
// Transparency related helpers (optional)
#if defined(_MSC_VER)
#pragma comment(lib, "dwmapi") // Link with dwmapi.lib. MinGW will require linking with '-ldwmapi'
// [experimental]
// Borrowed from GLFW's function updateFramebufferTransparency() in src/win32_window.c
// (the Dwm* functions are Vista era functions but we are borrowing logic from GLFW)
void ImGui_ImplWin32_EnableAlphaCompositing(void* hwnd)
if (!_IsWindowsVistaOrGreater())
BOOL composition;
if (FAILED(::DwmIsCompositionEnabled(&composition)) || !composition)
BOOL opaque;
DWORD color;
if (_IsWindows8OrGreater() || (SUCCEEDED(::DwmGetColorizationColor(&color, &opaque)) && !opaque))
HRGN region = ::CreateRectRgn(0, 0, -1, -1);
bb.hRgnBlur = region;
bb.fEnable = TRUE;
::DwmEnableBlurBehindWindow((HWND)hwnd, &bb);
bb.dwFlags = DWM_BB_ENABLE;
::DwmEnableBlurBehindWindow((HWND)hwnd, &bb);
// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
struct ImGui_ImplWin32_ViewportData
HWND Hwnd;
HWND HwndParent;
bool HwndOwned;
DWORD DwStyle;
DWORD DwExStyle;
ImGui_ImplWin32_ViewportData() { Hwnd = HwndParent = nullptr; HwndOwned = false; DwStyle = DwExStyle = 0; }
~ImGui_ImplWin32_ViewportData() { IM_ASSERT(Hwnd == nullptr); }
static void ImGui_ImplWin32_GetWin32StyleFromViewportFlags(ImGuiViewportFlags flags, DWORD* out_style, DWORD* out_ex_style)
if (flags & ImGuiViewportFlags_NoDecoration)
*out_style = WS_POPUP;
if (flags & ImGuiViewportFlags_NoTaskBarIcon)
*out_ex_style = WS_EX_TOOLWINDOW;
*out_ex_style = WS_EX_APPWINDOW;
if (flags & ImGuiViewportFlags_TopMost)
*out_ex_style |= WS_EX_TOPMOST;
static HWND ImGui_ImplWin32_GetHwndFromViewportID(ImGuiID viewport_id)
if (viewport_id != 0)
if (ImGuiViewport* viewport = ImGui::FindViewportByID(viewport_id))
return (HWND)viewport->PlatformHandle;
return nullptr;
static void ImGui_ImplWin32_CreateWindow(ImGuiViewport* viewport)
ImGui_ImplWin32_ViewportData* vd = IM_NEW(ImGui_ImplWin32_ViewportData)();
viewport->PlatformUserData = vd;
// Select style and parent window
ImGui_ImplWin32_GetWin32StyleFromViewportFlags(viewport->Flags, &vd->DwStyle, &vd->DwExStyle);
vd->HwndParent = ImGui_ImplWin32_GetHwndFromViewportID(viewport->ParentViewportId);
// Create window
RECT rect = { (LONG)viewport->Pos.x, (LONG)viewport->Pos.y, (LONG)(viewport->Pos.x + viewport->Size.x), (LONG)(viewport->Pos.y + viewport->Size.y) };
::AdjustWindowRectEx(&rect, vd->DwStyle, FALSE, vd->DwExStyle);
vd->Hwnd = ::CreateWindowEx(
vd->DwExStyle, _T("ImGui Platform"), _T("Untitled"), vd->DwStyle, // Style, class name, window name
rect.left,, rect.right - rect.left, rect.bottom -, // Window area
vd->HwndParent, nullptr, ::GetModuleHandle(nullptr), nullptr); // Owner window, Menu, Instance, Param
vd->HwndOwned = true;
viewport->PlatformRequestResize = false;
viewport->PlatformHandle = viewport->PlatformHandleRaw = vd->Hwnd;
static void ImGui_ImplWin32_DestroyWindow(ImGuiViewport* viewport)
ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
if (ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData)
if (::GetCapture() == vd->Hwnd)
// Transfer capture so if we started dragging from a window that later disappears, we'll still receive the MOUSEUP event.
if (vd->Hwnd && vd->HwndOwned)
vd->Hwnd = nullptr;
viewport->PlatformUserData = viewport->PlatformHandle = nullptr;
static void ImGui_ImplWin32_ShowWindow(ImGuiViewport* viewport)
ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
IM_ASSERT(vd->Hwnd != 0);
// ShowParent() also brings parent to front, which is not always desirable,
// so we temporarily disable parenting. (#7354)
if (vd->HwndParent != NULL)
::SetWindowLongPtr(vd->Hwnd, GWLP_HWNDPARENT, (LONG_PTR)nullptr);
if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing)
::ShowWindow(vd->Hwnd, SW_SHOWNA);
::ShowWindow(vd->Hwnd, SW_SHOW);
// Restore
if (vd->HwndParent != NULL)
::SetWindowLongPtr(vd->Hwnd, GWLP_HWNDPARENT, (LONG_PTR)vd->HwndParent);
static void ImGui_ImplWin32_UpdateWindow(ImGuiViewport* viewport)
ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
IM_ASSERT(vd->Hwnd != 0);
// Update Win32 parent if it changed _after_ creation
// Unlike style settings derived from configuration flags, this is more likely to change for advanced apps that are manipulating ParentViewportID manually.
HWND new_parent = ImGui_ImplWin32_GetHwndFromViewportID(viewport->ParentViewportId);
if (new_parent != vd->HwndParent)
// Win32 windows can either have a "Parent" (for WS_CHILD window) or an "Owner" (which among other thing keeps window above its owner).
// Our Dear Imgui-side concept of parenting only mostly care about what Win32 call "Owner".
// The parent parameter of CreateWindowEx() sets up Parent OR Owner depending on WS_CHILD flag. In our case an Owner as we never use WS_CHILD.
// Calling ::SetParent() here would be incorrect: it will create a full child relation, alter coordinate system and clipping.
// Calling ::SetWindowLongPtr() with GWLP_HWNDPARENT seems correct although poorly documented.
vd->HwndParent = new_parent;
::SetWindowLongPtr(vd->Hwnd, GWLP_HWNDPARENT, (LONG_PTR)vd->HwndParent);
// (Optional) Update Win32 style if it changed _after_ creation.
// Generally they won't change unless configuration flags are changed, but advanced uses (such as manually rewriting viewport flags) make this useful.
DWORD new_style;
DWORD new_ex_style;
ImGui_ImplWin32_GetWin32StyleFromViewportFlags(viewport->Flags, &new_style, &new_ex_style);
// Only reapply the flags that have been changed from our point of view (as other flags are being modified by Windows)
if (vd->DwStyle != new_style || vd->DwExStyle != new_ex_style)
// (Optional) Update TopMost state if it changed _after_ creation
bool top_most_changed = (vd->DwExStyle & WS_EX_TOPMOST) != (new_ex_style & WS_EX_TOPMOST);
HWND insert_after = top_most_changed ? ((viewport->Flags & ImGuiViewportFlags_TopMost) ? HWND_TOPMOST : HWND_NOTOPMOST) : 0;
UINT swp_flag = top_most_changed ? 0 : SWP_NOZORDER;
// Apply flags and position (since it is affected by flags)
vd->DwStyle = new_style;
vd->DwExStyle = new_ex_style;
::SetWindowLong(vd->Hwnd, GWL_STYLE, vd->DwStyle);
::SetWindowLong(vd->Hwnd, GWL_EXSTYLE, vd->DwExStyle);
RECT rect = { (LONG)viewport->Pos.x, (LONG)viewport->Pos.y, (LONG)(viewport->Pos.x + viewport->Size.x), (LONG)(viewport->Pos.y + viewport->Size.y) };
::AdjustWindowRectEx(&rect, vd->DwStyle, FALSE, vd->DwExStyle); // Client to Screen
::SetWindowPos(vd->Hwnd, insert_after, rect.left,, rect.right - rect.left, rect.bottom -, swp_flag | SWP_NOACTIVATE | SWP_FRAMECHANGED);
::ShowWindow(vd->Hwnd, SW_SHOWNA); // This is necessary when we alter the style
viewport->PlatformRequestMove = viewport->PlatformRequestResize = true;
static ImVec2 ImGui_ImplWin32_GetWindowPos(ImGuiViewport* viewport)
ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
IM_ASSERT(vd->Hwnd != 0);
POINT pos = { 0, 0 };
::ClientToScreen(vd->Hwnd, &pos);
return ImVec2((float)pos.x, (float)pos.y);
static void ImGui_ImplWin32_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
IM_ASSERT(vd->Hwnd != 0);
RECT rect = { (LONG)pos.x, (LONG)pos.y, (LONG)pos.x, (LONG)pos.y };
::AdjustWindowRectEx(&rect, vd->DwStyle, FALSE, vd->DwExStyle);
::SetWindowPos(vd->Hwnd, nullptr, rect.left,, 0, 0, SWP_NOZORDER | SWP_NOSIZE | SWP_NOACTIVATE);
static ImVec2 ImGui_ImplWin32_GetWindowSize(ImGuiViewport* viewport)
ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
IM_ASSERT(vd->Hwnd != 0);
RECT rect;
::GetClientRect(vd->Hwnd, &rect);
return ImVec2(float(rect.right - rect.left), float(rect.bottom -;
static void ImGui_ImplWin32_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
IM_ASSERT(vd->Hwnd != 0);
RECT rect = { 0, 0, (LONG)size.x, (LONG)size.y };
::AdjustWindowRectEx(&rect, vd->DwStyle, FALSE, vd->DwExStyle); // Client to Screen
::SetWindowPos(vd->Hwnd, nullptr, 0, 0, rect.right - rect.left, rect.bottom -, SWP_NOZORDER | SWP_NOMOVE | SWP_NOACTIVATE);
static void ImGui_ImplWin32_SetWindowFocus(ImGuiViewport* viewport)
ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
IM_ASSERT(vd->Hwnd != 0);
static bool ImGui_ImplWin32_GetWindowFocus(ImGuiViewport* viewport)
ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
IM_ASSERT(vd->Hwnd != 0);
return ::GetForegroundWindow() == vd->Hwnd;
static bool ImGui_ImplWin32_GetWindowMinimized(ImGuiViewport* viewport)
ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
IM_ASSERT(vd->Hwnd != 0);
return ::IsIconic(vd->Hwnd) != 0;
static void ImGui_ImplWin32_SetWindowTitle(ImGuiViewport* viewport, const char* title)
// ::SetWindowTextA() doesn't properly handle UTF-8 so we explicitely convert our string.
ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
IM_ASSERT(vd->Hwnd != 0);
int n = ::MultiByteToWideChar(CP_UTF8, 0, title, -1, nullptr, 0);
ImVector<wchar_t> title_w;
::MultiByteToWideChar(CP_UTF8, 0, title, -1, title_w.Data, n);
::SetWindowTextW(vd->Hwnd, title_w.Data);
static void ImGui_ImplWin32_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
IM_ASSERT(vd->Hwnd != 0);
IM_ASSERT(alpha >= 0.0f && alpha <= 1.0f);
if (alpha < 1.0f)
DWORD style = ::GetWindowLongW(vd->Hwnd, GWL_EXSTYLE) | WS_EX_LAYERED;
::SetWindowLongW(vd->Hwnd, GWL_EXSTYLE, style);
::SetLayeredWindowAttributes(vd->Hwnd, 0, (BYTE)(255 * alpha), LWA_ALPHA);
DWORD style = ::GetWindowLongW(vd->Hwnd, GWL_EXSTYLE) & ~WS_EX_LAYERED;
::SetWindowLongW(vd->Hwnd, GWL_EXSTYLE, style);
static float ImGui_ImplWin32_GetWindowDpiScale(ImGuiViewport* viewport)
ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
IM_ASSERT(vd->Hwnd != 0);
return ImGui_ImplWin32_GetDpiScaleForHwnd(vd->Hwnd);
// FIXME-DPI: Testing DPI related ideas
static void ImGui_ImplWin32_OnChangedViewport(ImGuiViewport* viewport)
#if 0
ImGuiStyle default_style;
//default_style.WindowPadding = ImVec2(0, 0);
//default_style.WindowBorderSize = 0.0f;
//default_style.ItemSpacing.y = 3.0f;
//default_style.FramePadding = ImVec2(0, 0);
ImGuiStyle& style = ImGui::GetStyle();
style = default_style;
static LRESULT CALLBACK ImGui_ImplWin32_WndProcHandler_PlatformWindow(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
if (ImGui_ImplWin32_WndProcHandler(hWnd, msg, wParam, lParam))
return true;
if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle((void*)hWnd))
switch (msg)
case WM_CLOSE:
viewport->PlatformRequestClose = true;
return 0;
case WM_MOVE:
viewport->PlatformRequestMove = true;
case WM_SIZE:
viewport->PlatformRequestResize = true;
if (viewport->Flags & ImGuiViewportFlags_NoFocusOnClick)
// Let mouse pass-through the window. This will allow the backend to call io.AddMouseViewportEvent() correctly. (which is optional).
// The ImGuiViewportFlags_NoInputs flag is set while dragging a viewport, as want to detect the window behind the one we are dragging.
// If you cannot easily access those viewport flags from your windowing/event code: you may manually synchronize its state e.g. in
// your main loop after calling UpdatePlatformWindows(). Iterate all viewports/platform windows and pass the flag to your windowing system.
if (viewport->Flags & ImGuiViewportFlags_NoInputs)
return DefWindowProc(hWnd, msg, wParam, lParam);
static void ImGui_ImplWin32_InitPlatformInterface(bool platform_has_own_dc)
wcex.cbSize = sizeof(WNDCLASSEX); = CS_HREDRAW | CS_VREDRAW | (platform_has_own_dc ? CS_OWNDC : 0);
wcex.lpfnWndProc = ImGui_ImplWin32_WndProcHandler_PlatformWindow;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = ::GetModuleHandle(nullptr);
wcex.hIcon = nullptr;
wcex.hCursor = nullptr;
wcex.hbrBackground = (HBRUSH)(COLOR_BACKGROUND + 1);
wcex.lpszMenuName = nullptr;
wcex.lpszClassName = _T("ImGui Platform");
wcex.hIconSm = nullptr;
// Register platform interface (will be coupled with a renderer interface)
ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
platform_io.Platform_CreateWindow = ImGui_ImplWin32_CreateWindow;
platform_io.Platform_DestroyWindow = ImGui_ImplWin32_DestroyWindow;
platform_io.Platform_ShowWindow = ImGui_ImplWin32_ShowWindow;
platform_io.Platform_SetWindowPos = ImGui_ImplWin32_SetWindowPos;
platform_io.Platform_GetWindowPos = ImGui_ImplWin32_GetWindowPos;
platform_io.Platform_SetWindowSize = ImGui_ImplWin32_SetWindowSize;
platform_io.Platform_GetWindowSize = ImGui_ImplWin32_GetWindowSize;
platform_io.Platform_SetWindowFocus = ImGui_ImplWin32_SetWindowFocus;
platform_io.Platform_GetWindowFocus = ImGui_ImplWin32_GetWindowFocus;
platform_io.Platform_GetWindowMinimized = ImGui_ImplWin32_GetWindowMinimized;
platform_io.Platform_SetWindowTitle = ImGui_ImplWin32_SetWindowTitle;
platform_io.Platform_SetWindowAlpha = ImGui_ImplWin32_SetWindowAlpha;
platform_io.Platform_UpdateWindow = ImGui_ImplWin32_UpdateWindow;
platform_io.Platform_GetWindowDpiScale = ImGui_ImplWin32_GetWindowDpiScale; // FIXME-DPI
platform_io.Platform_OnChangedViewport = ImGui_ImplWin32_OnChangedViewport; // FIXME-DPI
// Register main window handle (which is owned by the main application, not by us)
// This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.
ImGuiViewport* main_viewport = ImGui::GetMainViewport();
ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
ImGui_ImplWin32_ViewportData* vd = IM_NEW(ImGui_ImplWin32_ViewportData)();
vd->Hwnd = bd->hWnd;
vd->HwndOwned = false;
main_viewport->PlatformUserData = vd;
main_viewport->PlatformHandle = (void*)bd->hWnd;
static void ImGui_ImplWin32_ShutdownPlatformInterface()
::UnregisterClass(_T("ImGui Platform"), ::GetModuleHandle(nullptr));
#if defined(__GNUC__)
#pragma GCC diagnostic pop
#if defined(__clang__)
#pragma clang diagnostic pop
#endif // #ifndef IMGUI_DISABLE