// ImGui Platform Binding for: Windows (standard windows API for 32 and 64 bits applications) // This needs to be used along with a Renderer (e.g. DirectX11, OpenGL3, Vulkan..) #include "imgui.h" #include "imgui_impl_win32.h" #define WIN32_LEAN_AND_MEAN #include #include // CHANGELOG // 2018-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface. // 2018-03-20: Misc: Setup io.BackendFlags ImGuiBackendFlags_HasMouseCursors and ImGuiBackendFlags_HasSetMousePos flags + honor ImGuiConfigFlags_NoSetMouseCursor 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(NULL) when io.MouseDrawCursor is set. // Win32 Data static HWND g_hWnd = 0; static INT64 g_Time = 0; static INT64 g_TicksPerSecond = 0; static ImGuiMouseCursor g_LastMouseCursor = ImGuiMouseCursor_Count_; // Forward Declarations static void ImGui_ImplWin32_InitPlatformInterface(); static void ImGui_ImplWin32_ShutdownPlatformInterface(); // Functions bool ImGui_ImplWin32_Init(void* hwnd) { if (!::QueryPerformanceFrequency((LARGE_INTEGER *)&g_TicksPerSecond)) return false; if (!::QueryPerformanceCounter((LARGE_INTEGER *)&g_Time)) return false; // Setup back-end capabilities flags ImGuiIO& io = ImGui::GetIO(); 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 set io.MouseHoveredViewport correctly (optional, not easy) // Our mouse update function expect PlatformHandle to be filled for the main viewport g_hWnd = (HWND)hwnd; ImGuiViewport* main_viewport = ImGui::GetMainViewport(); main_viewport->PlatformHandle = (void*)g_hWnd; if (io.ConfigFlags & ImGuiConfigFlags_EnableViewports) ImGui_ImplWin32_InitPlatformInterface(); // Keyboard mapping. ImGui will use those indices to peek into the io.KeyDown[] array that we will update during the application lifetime. io.KeyMap[ImGuiKey_Tab] = VK_TAB; io.KeyMap[ImGuiKey_LeftArrow] = VK_LEFT; io.KeyMap[ImGuiKey_RightArrow] = VK_RIGHT; io.KeyMap[ImGuiKey_UpArrow] = VK_UP; io.KeyMap[ImGuiKey_DownArrow] = VK_DOWN; io.KeyMap[ImGuiKey_PageUp] = VK_PRIOR; io.KeyMap[ImGuiKey_PageDown] = VK_NEXT; io.KeyMap[ImGuiKey_Home] = VK_HOME; io.KeyMap[ImGuiKey_End] = VK_END; io.KeyMap[ImGuiKey_Insert] = VK_INSERT; io.KeyMap[ImGuiKey_Delete] = VK_DELETE; io.KeyMap[ImGuiKey_Backspace] = VK_BACK; io.KeyMap[ImGuiKey_Space] = VK_SPACE; io.KeyMap[ImGuiKey_Enter] = VK_RETURN; io.KeyMap[ImGuiKey_Escape] = VK_ESCAPE; io.KeyMap[ImGuiKey_A] = 'A'; io.KeyMap[ImGuiKey_C] = 'C'; io.KeyMap[ImGuiKey_V] = 'V'; io.KeyMap[ImGuiKey_X] = 'X'; io.KeyMap[ImGuiKey_Y] = 'Y'; io.KeyMap[ImGuiKey_Z] = 'Z'; io.ImeWindowHandle = g_hWnd; return true; } void ImGui_ImplWin32_Shutdown() { ImGui_ImplWin32_ShutdownPlatformInterface(); g_hWnd = (HWND)0; } static bool ImGui_ImplWin32_UpdateMouseCursor() { ImGuiIO& io = ImGui::GetIO(); if (io.ConfigFlags & ImGuiConfigFlags_NoSetMouseCursor) return false; ImGuiMouseCursor imgui_cursor = io.MouseDrawCursor ? ImGuiMouseCursor_None : ImGui::GetMouseCursor(); if (imgui_cursor == ImGuiMouseCursor_None) { // Hide OS mouse cursor if imgui is drawing it or if it wants no cursor ::SetCursor(NULL); } else { // Hardware cursor type 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; } ::SetCursor(::LoadCursor(NULL, win32_cursor)); } return true; } // This code supports multiple OS Windows mapped into different ImGui viewports, // So it is a little more complicated than your typical binding code (which only needs to set io.MousePos in your WM_MOUSEMOVE handler) // This is what imgui needs from the back-end to support multiple windows: // - io.MousePos = mouse position (e.g. io.MousePos == viewport->Pos when we are on the upper-left of our viewport) // - io.MousePosViewport = viewport which mouse position is based from (generally the focused/active/capturing viewport) // - io.MouseHoveredWindow = viewport which mouse is hovering, **regardless of it being the active/focused window**, **regardless of another window holding mouse captured**. [Optional] // This function overwrite the value of io.MousePos normally updated by the WM_MOUSEMOVE handler. // We keep the WM_MOUSEMOVE handling code so that WndProc function can be copied as-in in applications which do not need multiple OS windows support. static void ImGui_ImplWin32_UpdateMousePos() { ImGuiIO& io = ImGui::GetIO(); io.MousePos = ImVec2(-FLT_MAX, -FLT_MAX); io.MousePosViewport = 0; io.MouseHoveredViewport = 0; POINT pos; if (!::GetCursorPos(&pos)) return; // Our back-end can tell which window is under the mouse cursor (not every back-end can), so pass that info to imgui HWND hovered_hwnd = ::WindowFromPoint(pos); if (hovered_hwnd) if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle((void*)hovered_hwnd)) io.MouseHoveredViewport = viewport->ID; // Convert mouse from screen position to window client position HWND focused_hwnd = ::GetActiveWindow(); if (focused_hwnd != 0 && ::ScreenToClient(focused_hwnd, &pos)) if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle((void*)focused_hwnd)) { io.MousePos = ImVec2(viewport->Pos.x + (float)pos.x, viewport->Pos.y + (float)pos.y); io.MousePosViewport = viewport->ID; } } void ImGui_ImplWin32_NewFrame() { ImGuiIO& io = ImGui::GetIO(); // Setup display size (every frame to accommodate for window resizing) RECT rect; ::GetClientRect(g_hWnd, &rect); io.DisplaySize = ImVec2((float)(rect.right - rect.left), (float)(rect.bottom - rect.top)); // Setup time step INT64 current_time; ::QueryPerformanceCounter((LARGE_INTEGER *)¤t_time); io.DeltaTime = (float)(current_time - g_Time) / g_TicksPerSecond; g_Time = current_time; // Read keyboard modifiers inputs io.KeyCtrl = (::GetKeyState(VK_CONTROL) & 0x8000) != 0; io.KeyShift = (::GetKeyState(VK_SHIFT) & 0x8000) != 0; io.KeyAlt = (::GetKeyState(VK_MENU) & 0x8000) != 0; io.KeySuper = false; // io.KeysDown : filled by WM_KEYDOWN/WM_KEYUP events // io.MousePos : filled by WM_MOUSEMOVE events // io.MouseDown : filled by WM_*BUTTON* events // io.MouseWheel : filled by WM_MOUSEWHEEL events // Set OS mouse position if requested (only used when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user) if (io.WantSetMousePos) { POINT pos = { (int)io.MousePos.x, (int)io.MousePos.y }; ::ClientToScreen(g_hWnd, &pos); ::SetCursorPos(pos.x, pos.y); } // Update OS mouse cursor with the cursor requested by imgui ImGuiMouseCursor mouse_cursor = io.MouseDrawCursor ? ImGuiMouseCursor_None : ImGui::GetMouseCursor(); if (g_LastMouseCursor != mouse_cursor) { g_LastMouseCursor = mouse_cursor; ImGui_ImplWin32_UpdateMouseCursor(); } ImGui_ImplWin32_UpdateMousePos(); // Start the frame. This call will update the io.WantCaptureMouse, io.WantCaptureKeyboard flag that you can use to dispatch inputs (or not) to your application. ImGui::NewFrame(); } // Allow compilation with old Windows SDK. MinGW doesn't have default _WIN32_WINNT/WINVER versions. #ifndef WM_MOUSEHWHEEL #define WM_MOUSEHWHEEL 0x020E #endif // Process Win32 mouse/keyboard inputs. // 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. // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application. // 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 coordinations 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. IMGUI_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) { if (ImGui::GetCurrentContext() == NULL) return 0; ImGuiIO& io = ImGui::GetIO(); switch (msg) { case WM_LBUTTONDOWN: case WM_LBUTTONDBLCLK: case WM_RBUTTONDOWN: case WM_RBUTTONDBLCLK: case WM_MBUTTONDOWN: case WM_MBUTTONDBLCLK: { 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 (!ImGui::IsAnyMouseDown() && ::GetCapture() == NULL) ::SetCapture(hwnd); io.MouseDown[button] = true; return 0; } case WM_LBUTTONUP: case WM_RBUTTONUP: case WM_MBUTTONUP: { int button = 0; if (msg == WM_LBUTTONUP) button = 0; if (msg == WM_RBUTTONUP) button = 1; if (msg == WM_MBUTTONUP) button = 2; io.MouseDown[button] = false; if (!ImGui::IsAnyMouseDown() && ::GetCapture() == hwnd) ::ReleaseCapture(); return 0; } case WM_MOUSEWHEEL: io.MouseWheel += GET_WHEEL_DELTA_WPARAM(wParam) > 0 ? +1.0f : -1.0f; return 0; case WM_MOUSEHWHEEL: io.MouseWheelH += GET_WHEEL_DELTA_WPARAM(wParam) > 0 ? +1.0f : -1.0f; return 0; case WM_MOUSEMOVE: io.MousePos.x = (signed short)(lParam); io.MousePos.y = (signed short)(lParam >> 16); return 0; case WM_KEYDOWN: case WM_SYSKEYDOWN: if (wParam < 256) io.KeysDown[wParam] = 1; return 0; case WM_KEYUP: case WM_SYSKEYUP: if (wParam < 256) io.KeysDown[wParam] = 0; return 0; case WM_CHAR: // You can also use ToAscii()+GetKeyboardState() to retrieve characters. if (wParam > 0 && wParam < 0x10000) io.AddInputCharacter((unsigned short)wParam); return 0; case WM_SETCURSOR: if (LOWORD(lParam) == HTCLIENT && ImGui_ImplWin32_UpdateMouseCursor()) return 1; return 0; } return 0; } // -------------------------------------------------------------------------------------------------------- // DPI handling // Those in theory should be simple calls but Windows has multiple ways to handle DPI, and most of them // require recent Windows versions at runtime or recent Windows SDK at compile-time. Neither we want to depend on. // 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 here) and other applications aiming to be portable. //--------------------------------------------------------------------------------------------------------- // FIXME-DPI: For now we just call SetProcessDpiAwareness(PROCESS_PER_MONITOR_AWARE) without requiring SDK 8.1 or 10. // We may allow/aim calling the most-recent-available version, e.g. Windows 10 Creators Update has SetThreadDpiAwarenessContext(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2); // At this point ImGui_ImplWin32_EnableDpiAwareness() is just a helper called by main.cpp, we don't call it ourselves. //--------------------------------------------------------------------------------------------------------- static BOOL IsWindowsVersionOrGreater(WORD major, WORD minor, WORD sp) { OSVERSIONINFOEXW osvi = { sizeof(osvi), major, minor, 0, 0,{ 0 }, sp }; DWORD mask = VER_MAJORVERSION | VER_MINORVERSION | VER_SERVICEPACKMAJOR; ULONGLONG cond = VerSetConditionMask(0, VER_MAJORVERSION, VER_GREATER_EQUAL); cond = VerSetConditionMask(cond, VER_MINORVERSION, VER_GREATER_EQUAL); cond = VerSetConditionMask(cond, VER_SERVICEPACKMAJOR, VER_GREATER_EQUAL); return VerifyVersionInfoW(&osvi, mask, cond); } #define IsWindows8Point1OrGreater() IsWindowsVersionOrGreater(HIBYTE(0x0602), LOBYTE(0x0602), 0) // _WIN32_WINNT_WINBLUE #define IsWindows10OrGreater() IsWindowsVersionOrGreater(HIBYTE(0x0A00), LOBYTE(0x0A00), 0) // _WIN32_WINNT_WIN10 #ifndef DPI_ENUMS_DECLARED typedef enum { PROCESS_DPI_UNAWARE = 0, PROCESS_SYSTEM_DPI_AWARE = 1, PROCESS_PER_MONITOR_DPI_AWARE = 2 } PROCESS_DPI_AWARENESS; typedef enum { MDT_EFFECTIVE_DPI = 0, MDT_ANGULAR_DPI = 1, MDT_RAW_DPI = 2, MDT_DEFAULT = MDT_EFFECTIVE_DPI } MONITOR_DPI_TYPE; #endif 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 void ImGui_ImplWin32_EnableDpiAwareness() { if (IsWindows8Point1OrGreater()) { static HINSTANCE shcore_dll = ::LoadLibraryA("shcore.dll"); // Reference counted per-process if (PFN_SetProcessDpiAwareness SetProcessDpiAwarenessFn = (PFN_SetProcessDpiAwareness)::GetProcAddress(shcore_dll, "SetProcessDpiAwareness")) SetProcessDpiAwarenessFn(PROCESS_PER_MONITOR_DPI_AWARE); } else { SetProcessDPIAware(); } } float ImGui_ImplWin32_GetDpiScaleForMonitor(void* monitor) { UINT xdpi = 96, ydpi = 96; if (IsWindows8Point1OrGreater()) { static HINSTANCE shcore_dll = ::LoadLibraryA("shcore.dll"); // Reference counted per-process if (PFN_GetDpiForMonitor GetDpiForMonitorFn = (PFN_GetDpiForMonitor)::GetProcAddress(shcore_dll, "GetDpiForMonitor")) GetDpiForMonitorFn((HMONITOR)monitor, MDT_EFFECTIVE_DPI, &xdpi, &ydpi); } else { const HDC dc = ::GetDC(NULL); xdpi = ::GetDeviceCaps(dc, LOGPIXELSX); ydpi = ::GetDeviceCaps(dc, LOGPIXELSY); ::ReleaseDC(NULL, dc); } IM_ASSERT(xdpi == ydpi); // Please contact me if you hit this assert! return xdpi / 96.0f; } float ImGui_ImplWin32_GetDpiScaleForHwnd(void* hwnd) { HMONITOR monitor = ::MonitorFromWindow((HWND)hwnd, MONITOR_DEFAULTTONEAREST); return ImGui_ImplWin32_GetDpiScaleForMonitor(monitor); } float ImGui_ImplWin32_GetDpiScaleForRect(int x1, int y1, int x2, int y2) { RECT viewport_rect = { (LONG)x1, (LONG)y1, (LONG)x2, (LONG)y2 }; HMONITOR monitor = ::MonitorFromRect(&viewport_rect, MONITOR_DEFAULTTONEAREST); return ImGui_ImplWin32_GetDpiScaleForMonitor(monitor); } // -------------------------------------------------------------------------------------------------------- // Platform Windows // -------------------------------------------------------------------------------------------------------- struct ImGuiViewportDataWin32 { HWND Hwnd; DWORD DwStyle; DWORD DwExStyle; ImGuiViewportDataWin32() { Hwnd = NULL; DwStyle = DwExStyle = 0; } ~ImGuiViewportDataWin32() { IM_ASSERT(Hwnd == NULL); } }; static void ImGui_ImplWin32_CreateWindow(ImGuiViewport* viewport) { ImGuiViewportDataWin32* data = IM_NEW(ImGuiViewportDataWin32)(); viewport->PlatformUserData = data; ImGuiIO& io = ImGui::GetIO(); bool no_decoration = (viewport->Flags & ImGuiViewportFlags_NoDecoration) != 0; bool no_task_bar = (io.ConfigFlags & ImGuiConfigFlags_NoTaskBarForViewports) != 0; if (no_decoration) { data->DwStyle = WS_POPUP; data->DwExStyle = no_task_bar ? WS_EX_TOOLWINDOW : WS_EX_APPWINDOW; } else { data->DwStyle = WS_OVERLAPPEDWINDOW; data->DwExStyle = no_task_bar ? WS_EX_TOOLWINDOW : WS_EX_APPWINDOW; } // Create window RECT rect = { (LONG)viewport->PlatformPos.x, (LONG)viewport->PlatformPos.y, (LONG)(viewport->PlatformPos.x + viewport->Size.x), (LONG)(viewport->PlatformPos.y + viewport->Size.y) }; ::AdjustWindowRectEx(&rect, data->DwStyle, FALSE, data->DwExStyle); data->Hwnd = ::CreateWindowExA( data->DwExStyle, "ImGui Platform", "No Title Yet", data->DwStyle, // Style, class name, window name rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top, // Window area g_hWnd, NULL, ::GetModuleHandle(NULL), NULL); // Parent window, Menu, Instance, Param viewport->PlatformRequestResize = false; viewport->PlatformHandle = data->Hwnd; } static void ImGui_ImplWin32_DestroyWindow(ImGuiViewport* viewport) { if (ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData) { if (::GetCapture() == data->Hwnd) { // Transfer capture so if we started dragging from a window that later disappears, we'll still release the MOUSEUP event. ::ReleaseCapture(); ::SetCapture(g_hWnd); } if (data->Hwnd) ::DestroyWindow(data->Hwnd); data->Hwnd = NULL; IM_DELETE(data); } viewport->PlatformUserData = viewport->PlatformHandle = NULL; } static void ImGui_ImplWin32_ShowWindow(ImGuiViewport* viewport) { ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData; IM_ASSERT(data->Hwnd != 0); if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing) ::ShowWindow(data->Hwnd, SW_SHOWNA); else ::ShowWindow(data->Hwnd, SW_SHOW); } static ImVec2 ImGui_ImplWin32_GetWindowPos(ImGuiViewport* viewport) { ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData; IM_ASSERT(data->Hwnd != 0); POINT pos = { 0, 0 }; ::ClientToScreen(data->Hwnd, &pos); return ImVec2((float)pos.x, (float)pos.y); } static void ImGui_ImplWin32_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos) { ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData; IM_ASSERT(data->Hwnd != 0); RECT rect = { (LONG)pos.x, (LONG)pos.y, (LONG)pos.x, (LONG)pos.y }; ::AdjustWindowRectEx(&rect, data->DwStyle, FALSE, data->DwExStyle); ::SetWindowPos(data->Hwnd, NULL, rect.left, rect.top, 0, 0, SWP_NOZORDER | SWP_NOSIZE | SWP_NOACTIVATE); } static ImVec2 ImGui_ImplWin32_GetWindowSize(ImGuiViewport* viewport) { ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData; IM_ASSERT(data->Hwnd != 0); RECT rect; ::GetClientRect(data->Hwnd, &rect); return ImVec2(float(rect.right - rect.left), float(rect.bottom - rect.top)); } static void ImGui_ImplWin32_SetWindowSize(ImGuiViewport* viewport, ImVec2 size) { ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData; IM_ASSERT(data->Hwnd != 0); RECT rect = { 0, 0, (LONG)size.x, (LONG)size.y }; ::AdjustWindowRectEx(&rect, data->DwStyle, FALSE, data->DwExStyle); // Client to Screen ::SetWindowPos(data->Hwnd, NULL, 0, 0, rect.right - rect.left, rect.bottom - rect.top, SWP_NOZORDER | SWP_NOMOVE | SWP_NOACTIVATE); } static void ImGui_ImplWin32_SetWindowTitle(ImGuiViewport* viewport, const char* title) { ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData; IM_ASSERT(data->Hwnd != 0); ::SetWindowTextA(data->Hwnd, title); } static float ImGui_ImplWin32_GetWindowDpiScale(ImGuiViewport* viewport) { ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData; if (data && data->Hwnd) return ImGui_ImplWin32_GetDpiScaleForHwnd(data->Hwnd); // The first frame a viewport is created we don't have a window yet return ImGui_ImplWin32_GetDpiScaleForRect( (int)(viewport->PlatformPos.x), (int)(viewport->PlatformPos.y), (int)(viewport->PlatformPos.x + viewport->Size.x), (int)(viewport->PlatformPos.y + viewport->Size.y)); } 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; break; case WM_SIZE: viewport->PlatformRequestResize = true; break; case WM_NCHITTEST: // Let mouse pass-through the window. This will allow the back-end to set io.MouseHoveredViewport properly (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 HTTRANSPARENT; break; } } return DefWindowProc(hWnd, msg, wParam, lParam); } static void ImGui_ImplWin32_InitPlatformInterface() { WNDCLASSEX wcex; wcex.cbSize = sizeof(WNDCLASSEX); wcex.style = CS_HREDRAW | CS_VREDRAW; wcex.lpfnWndProc = ImGui_ImplWin32_WndProcHandler_PlatformWindow; wcex.cbClsExtra = 0; wcex.cbWndExtra = 0; wcex.hInstance = ::GetModuleHandle(NULL); wcex.hIcon = NULL; wcex.hCursor = NULL; wcex.hbrBackground = (HBRUSH)(COLOR_BACKGROUND + 1); wcex.lpszMenuName = NULL; wcex.lpszClassName = _T("ImGui Platform"); wcex.hIconSm = NULL; ::RegisterClassEx(&wcex); // 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_SetWindowTitle = ImGui_ImplWin32_SetWindowTitle; platform_io.Platform_GetWindowDpiScale = ImGui_ImplWin32_GetWindowDpiScale; // Register main window handle ImGuiViewport* main_viewport = ImGui::GetMainViewport(); ImGuiViewportDataWin32* data = IM_NEW(ImGuiViewportDataWin32)(); data->Hwnd = g_hWnd; main_viewport->PlatformUserData = data; main_viewport->PlatformHandle = (void*)data->Hwnd; } static void ImGui_ImplWin32_ShutdownPlatformInterface() { ::UnregisterClass(_T("ImGui Platform"), ::GetModuleHandle(NULL)); }