1 // dear imgui: Platform Backend for Windows (standard windows API for 32 and 64 bits applications)
2 // This needs to be used along with a Renderer (e.g. DirectX11, OpenGL3, Vulkan..)
3
4 // Implemented features:
5 // [X] Platform: Clipboard support (for Win32 this is actually part of core dear imgui)
6 // [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
7 // [X] Platform: Keyboard arrays indexed using VK_* Virtual Key Codes, e.g. ImGui::IsKeyPressed(VK_SPACE).
8 // [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
9
10 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
11 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
12 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
13 // Read online: https://github.com/ocornut/imgui/tree/master/docs
14
15 #include "imgui.h"
16 #include "imgui_impl_win32.h"
17 #ifndef WIN32_LEAN_AND_MEAN
18 #define WIN32_LEAN_AND_MEAN
19 #endif
20 #include <windows.h>
21 #include <tchar.h>
22 #include <dwmapi.h>
23
24 // Configuration flags to add in your imconfig.h file:
25 //#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.
26
27 // Using XInput for gamepad (will load DLL dynamically)
28 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
29 #include <xinput.h>
30 typedef DWORD (WINAPI *PFN_XInputGetCapabilities)(DWORD, DWORD, XINPUT_CAPABILITIES*);
31 typedef DWORD (WINAPI *PFN_XInputGetState)(DWORD, XINPUT_STATE*);
32 #endif
33
34 // CHANGELOG
35 // (minor and older changes stripped away, please see git history for details)
36 // 2021-08-17: Calling io.AddFocusEvent() on WM_SETFOCUS/WM_KILLFOCUS messages.
37 // 2021-08-02: Inputs: Fixed keyboard modifiers being reported when host windo doesn't have focus.
38 // 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).
39 // 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).
40 // 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).
41 // 2021-03-23: Inputs: Clearing keyboard down array when losing focus (WM_KILLFOCUS).
42 // 2021-02-18: Added ImGui_ImplWin32_EnableAlphaCompositing(). Non Visual Studio users will need to link with dwmapi.lib (MinGW/gcc: use -ldwmapi).
43 // 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.
44 // 2021-01-25: Inputs: Dynamically loading XInput DLL.
45 // 2020-12-04: Misc: Fixed setting of io.DisplaySize to invalid/uninitialized data when after hwnd has been closed.
46 // 2020-03-03: Inputs: Calling AddInputCharacterUTF16() to support surrogate pairs leading to codepoint >= 0x10000 (for more complete CJK inputs)
47 // 2020-02-17: Added ImGui_ImplWin32_EnableDpiAwareness(), ImGui_ImplWin32_GetDpiScaleForHwnd(), ImGui_ImplWin32_GetDpiScaleForMonitor() helper functions.
48 // 2020-01-14: Inputs: Added support for #define IMGUI_IMPL_WIN32_DISABLE_GAMEPAD/IMGUI_IMPL_WIN32_DISABLE_LINKING_XINPUT.
49 // 2019-12-05: Inputs: Added support for ImGuiMouseCursor_NotAllowed mouse cursor.
50 // 2019-05-11: Inputs: Don't filter value from WM_CHAR before calling AddInputCharacter().
51 // 2019-01-17: Misc: Using GetForegroundWindow()+IsChild() instead of GetActiveWindow() to be compatible with windows created in a different thread or parent.
52 // 2019-01-17: Inputs: Added support for mouse buttons 4 and 5 via WM_XBUTTON* messages.
53 // 2019-01-15: Inputs: Added support for XInput gamepads (if ImGuiConfigFlags_NavEnableGamepad is set by user application).
54 // 2018-11-30: Misc: Setting up io.BackendPlatformName so it can be displayed in the About Window.
55 // 2018-06-29: Inputs: Added support for the ImGuiMouseCursor_Hand cursor.
56 // 2018-06-10: Inputs: Fixed handling of mouse wheel messages to support fine position messages (typically sent by track-pads).
57 // 2018-06-08: Misc: Extracted imgui_impl_win32.cpp/.h away from the old combined DX9/DX10/DX11/DX12 examples.
58 // 2018-03-20: Misc: Setup io.BackendFlags ImGuiBackendFlags_HasMouseCursors and ImGuiBackendFlags_HasSetMousePos flags + honor ImGuiConfigFlags_NoMouseCursorChange flag.
59 // 2018-02-20: Inputs: Added support for mouse cursors (ImGui::GetMouseCursor() value and WM_SETCURSOR message handling).
60 // 2018-02-06: Inputs: Added mapping for ImGuiKey_Space.
61 // 2018-02-06: Inputs: Honoring the io.WantSetMousePos by repositioning the mouse (when using navigation and ImGuiConfigFlags_NavMoveMouse is set).
62 // 2018-02-06: Misc: Removed call to ImGui::Shutdown() which is not available from 1.60 WIP, user needs to call CreateContext/DestroyContext themselves.
63 // 2018-01-20: Inputs: Added Horizontal Mouse Wheel support.
64 // 2018-01-08: Inputs: Added mapping for ImGuiKey_Insert.
65 // 2018-01-05: Inputs: Added WM_LBUTTONDBLCLK double-click handlers for window classes with the CS_DBLCLKS flag.
66 // 2017-10-23: Inputs: Added WM_SYSKEYDOWN / WM_SYSKEYUP handlers so e.g. the VK_MENU key can be read.
67 // 2017-10-23: Inputs: Using Win32 ::SetCapture/::GetCapture() to retrieve mouse positions outside the client area when dragging.
68 // 2016-11-12: Inputs: Only call Win32 ::SetCursor(NULL) when io.MouseDrawCursor is set.
69
70 struct ImGui_ImplWin32_Data
71 {
72 HWND hWnd;
73 HWND MouseHwnd;
74 bool MouseTracked;
75 INT64 Time;
76 INT64 TicksPerSecond;
77 ImGuiMouseCursor LastMouseCursor;
78 bool HasGamepad;
79 bool WantUpdateHasGamepad;
80
81 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
82 HMODULE XInputDLL;
83 PFN_XInputGetCapabilities XInputGetCapabilities;
84 PFN_XInputGetState XInputGetState;
85 #endif
86
ImGui_ImplWin32_DataImGui_ImplWin32_Data87 ImGui_ImplWin32_Data() { memset(this, 0, sizeof(*this)); }
88 };
89
90 // Backend data stored in io.BackendPlatformUserData to allow support for multiple Dear ImGui contexts
91 // It is STRONGLY preferred that you use docking branch with multi-viewports (== single Dear ImGui context + multiple windows) instead of multiple Dear ImGui contexts.
92 // FIXME: multi-context support is not well tested and probably dysfunctional in this backend.
93 // FIXME: some shared resources (mouse cursor shape, gamepad) are mishandled when using multi-context.
ImGui_ImplWin32_GetBackendData()94 static ImGui_ImplWin32_Data* ImGui_ImplWin32_GetBackendData()
95 {
96 return ImGui::GetCurrentContext() ? (ImGui_ImplWin32_Data*)ImGui::GetIO().BackendPlatformUserData : NULL;
97 }
98
99 // Functions
ImGui_ImplWin32_Init(void * hwnd)100 bool ImGui_ImplWin32_Init(void* hwnd)
101 {
102 ImGuiIO& io = ImGui::GetIO();
103 IM_ASSERT(io.BackendPlatformUserData == NULL && "Already initialized a platform backend!");
104
105 INT64 perf_frequency, perf_counter;
106 if (!::QueryPerformanceFrequency((LARGE_INTEGER*)&perf_frequency))
107 return false;
108 if (!::QueryPerformanceCounter((LARGE_INTEGER*)&perf_counter))
109 return false;
110
111 // Setup backend capabilities flags
112 ImGui_ImplWin32_Data* bd = IM_NEW(ImGui_ImplWin32_Data)();
113 io.BackendPlatformUserData = (void*)bd;
114 io.BackendPlatformName = "imgui_impl_win32";
115 io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors; // We can honor GetMouseCursor() values (optional)
116 io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos; // We can honor io.WantSetMousePos requests (optional, rarely used)
117
118 bd->hWnd = (HWND)hwnd;
119 bd->WantUpdateHasGamepad = true;
120 bd->TicksPerSecond = perf_frequency;
121 bd->Time = perf_counter;
122 bd->LastMouseCursor = ImGuiMouseCursor_COUNT;
123
124 io.ImeWindowHandle = hwnd;
125
126 // Keyboard mapping. Dear ImGui will use those indices to peek into the io.KeysDown[] array that we will update during the application lifetime.
127 io.KeyMap[ImGuiKey_Tab] = VK_TAB;
128 io.KeyMap[ImGuiKey_LeftArrow] = VK_LEFT;
129 io.KeyMap[ImGuiKey_RightArrow] = VK_RIGHT;
130 io.KeyMap[ImGuiKey_UpArrow] = VK_UP;
131 io.KeyMap[ImGuiKey_DownArrow] = VK_DOWN;
132 io.KeyMap[ImGuiKey_PageUp] = VK_PRIOR;
133 io.KeyMap[ImGuiKey_PageDown] = VK_NEXT;
134 io.KeyMap[ImGuiKey_Home] = VK_HOME;
135 io.KeyMap[ImGuiKey_End] = VK_END;
136 io.KeyMap[ImGuiKey_Insert] = VK_INSERT;
137 io.KeyMap[ImGuiKey_Delete] = VK_DELETE;
138 io.KeyMap[ImGuiKey_Backspace] = VK_BACK;
139 io.KeyMap[ImGuiKey_Space] = VK_SPACE;
140 io.KeyMap[ImGuiKey_Enter] = VK_RETURN;
141 io.KeyMap[ImGuiKey_Escape] = VK_ESCAPE;
142 io.KeyMap[ImGuiKey_KeyPadEnter] = VK_RETURN;
143 io.KeyMap[ImGuiKey_A] = 'A';
144 io.KeyMap[ImGuiKey_C] = 'C';
145 io.KeyMap[ImGuiKey_V] = 'V';
146 io.KeyMap[ImGuiKey_X] = 'X';
147 io.KeyMap[ImGuiKey_Y] = 'Y';
148 io.KeyMap[ImGuiKey_Z] = 'Z';
149
150 // Dynamically load XInput library
151 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
152 const char* xinput_dll_names[] =
153 {
154 "xinput1_4.dll", // Windows 8+
155 "xinput1_3.dll", // DirectX SDK
156 "xinput9_1_0.dll", // Windows Vista, Windows 7
157 "xinput1_2.dll", // DirectX SDK
158 "xinput1_1.dll" // DirectX SDK
159 };
160 for (int n = 0; n < IM_ARRAYSIZE(xinput_dll_names); n++)
161 if (HMODULE dll = ::LoadLibraryA(xinput_dll_names[n]))
162 {
163 bd->XInputDLL = dll;
164 bd->XInputGetCapabilities = (PFN_XInputGetCapabilities)::GetProcAddress(dll, "XInputGetCapabilities");
165 bd->XInputGetState = (PFN_XInputGetState)::GetProcAddress(dll, "XInputGetState");
166 break;
167 }
168 #endif // IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
169
170 return true;
171 }
172
ImGui_ImplWin32_Shutdown()173 void ImGui_ImplWin32_Shutdown()
174 {
175 ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
176 IM_ASSERT(bd != NULL && "No platform backend to shutdown, or already shutdown?");
177 ImGuiIO& io = ImGui::GetIO();
178
179 // Unload XInput library
180 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
181 if (bd->XInputDLL)
182 ::FreeLibrary(bd->XInputDLL);
183 #endif // IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
184
185 io.BackendPlatformName = NULL;
186 io.BackendPlatformUserData = NULL;
187 IM_DELETE(bd);
188 }
189
ImGui_ImplWin32_UpdateMouseCursor()190 static bool ImGui_ImplWin32_UpdateMouseCursor()
191 {
192 ImGuiIO& io = ImGui::GetIO();
193 if (io.ConfigFlags & ImGuiConfigFlags_NoMouseCursorChange)
194 return false;
195
196 ImGuiMouseCursor imgui_cursor = ImGui::GetMouseCursor();
197 if (imgui_cursor == ImGuiMouseCursor_None || io.MouseDrawCursor)
198 {
199 // Hide OS mouse cursor if imgui is drawing it or if it wants no cursor
200 ::SetCursor(NULL);
201 }
202 else
203 {
204 // Show OS mouse cursor
205 LPTSTR win32_cursor = IDC_ARROW;
206 switch (imgui_cursor)
207 {
208 case ImGuiMouseCursor_Arrow: win32_cursor = IDC_ARROW; break;
209 case ImGuiMouseCursor_TextInput: win32_cursor = IDC_IBEAM; break;
210 case ImGuiMouseCursor_ResizeAll: win32_cursor = IDC_SIZEALL; break;
211 case ImGuiMouseCursor_ResizeEW: win32_cursor = IDC_SIZEWE; break;
212 case ImGuiMouseCursor_ResizeNS: win32_cursor = IDC_SIZENS; break;
213 case ImGuiMouseCursor_ResizeNESW: win32_cursor = IDC_SIZENESW; break;
214 case ImGuiMouseCursor_ResizeNWSE: win32_cursor = IDC_SIZENWSE; break;
215 case ImGuiMouseCursor_Hand: win32_cursor = IDC_HAND; break;
216 case ImGuiMouseCursor_NotAllowed: win32_cursor = IDC_NO; break;
217 }
218 ::SetCursor(::LoadCursor(NULL, win32_cursor));
219 }
220 return true;
221 }
222
ImGui_ImplWin32_UpdateMousePos()223 static void ImGui_ImplWin32_UpdateMousePos()
224 {
225 ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
226 ImGuiIO& io = ImGui::GetIO();
227 IM_ASSERT(bd->hWnd != 0);
228
229 const ImVec2 mouse_pos_prev = io.MousePos;
230 io.MousePos = ImVec2(-FLT_MAX, -FLT_MAX);
231
232 // Obtain focused and hovered window. We forward mouse input when focused or when hovered (and no other window is capturing)
233 HWND focused_window = ::GetForegroundWindow();
234 HWND hovered_window = bd->MouseHwnd;
235 HWND mouse_window = NULL;
236 if (hovered_window && (hovered_window == bd->hWnd || ::IsChild(hovered_window, bd->hWnd)))
237 mouse_window = hovered_window;
238 else if (focused_window && (focused_window == bd->hWnd || ::IsChild(focused_window, bd->hWnd)))
239 mouse_window = focused_window;
240 if (mouse_window == NULL)
241 return;
242
243 // Set OS mouse position from Dear ImGui if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user)
244 if (io.WantSetMousePos)
245 {
246 POINT pos = { (int)mouse_pos_prev.x, (int)mouse_pos_prev.y };
247 if (::ClientToScreen(bd->hWnd, &pos))
248 ::SetCursorPos(pos.x, pos.y);
249 }
250
251 // Set Dear ImGui mouse position from OS position
252 POINT pos;
253 if (::GetCursorPos(&pos) && ::ScreenToClient(mouse_window, &pos))
254 io.MousePos = ImVec2((float)pos.x, (float)pos.y);
255 }
256
257 // Gamepad navigation mapping
ImGui_ImplWin32_UpdateGamepads()258 static void ImGui_ImplWin32_UpdateGamepads()
259 {
260 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
261 ImGuiIO& io = ImGui::GetIO();
262 ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
263 memset(io.NavInputs, 0, sizeof(io.NavInputs));
264 if ((io.ConfigFlags & ImGuiConfigFlags_NavEnableGamepad) == 0)
265 return;
266
267 // Calling XInputGetState() every frame on disconnected gamepads is unfortunately too slow.
268 // Instead we refresh gamepad availability by calling XInputGetCapabilities() _only_ after receiving WM_DEVICECHANGE.
269 if (bd->WantUpdateHasGamepad)
270 {
271 XINPUT_CAPABILITIES caps;
272 bd->HasGamepad = bd->XInputGetCapabilities ? (bd->XInputGetCapabilities(0, XINPUT_FLAG_GAMEPAD, &caps) == ERROR_SUCCESS) : false;
273 bd->WantUpdateHasGamepad = false;
274 }
275
276 io.BackendFlags &= ~ImGuiBackendFlags_HasGamepad;
277 XINPUT_STATE xinput_state;
278 if (bd->HasGamepad && bd->XInputGetState && bd->XInputGetState(0, &xinput_state) == ERROR_SUCCESS)
279 {
280 const XINPUT_GAMEPAD& gamepad = xinput_state.Gamepad;
281 io.BackendFlags |= ImGuiBackendFlags_HasGamepad;
282
283 #define MAP_BUTTON(NAV_NO, BUTTON_ENUM) { io.NavInputs[NAV_NO] = (gamepad.wButtons & BUTTON_ENUM) ? 1.0f : 0.0f; }
284 #define MAP_ANALOG(NAV_NO, VALUE, V0, V1) { float vn = (float)(VALUE - V0) / (float)(V1 - V0); if (vn > 1.0f) vn = 1.0f; if (vn > 0.0f && io.NavInputs[NAV_NO] < vn) io.NavInputs[NAV_NO] = vn; }
285 MAP_BUTTON(ImGuiNavInput_Activate, XINPUT_GAMEPAD_A); // Cross / A
286 MAP_BUTTON(ImGuiNavInput_Cancel, XINPUT_GAMEPAD_B); // Circle / B
287 MAP_BUTTON(ImGuiNavInput_Menu, XINPUT_GAMEPAD_X); // Square / X
288 MAP_BUTTON(ImGuiNavInput_Input, XINPUT_GAMEPAD_Y); // Triangle / Y
289 MAP_BUTTON(ImGuiNavInput_DpadLeft, XINPUT_GAMEPAD_DPAD_LEFT); // D-Pad Left
290 MAP_BUTTON(ImGuiNavInput_DpadRight, XINPUT_GAMEPAD_DPAD_RIGHT); // D-Pad Right
291 MAP_BUTTON(ImGuiNavInput_DpadUp, XINPUT_GAMEPAD_DPAD_UP); // D-Pad Up
292 MAP_BUTTON(ImGuiNavInput_DpadDown, XINPUT_GAMEPAD_DPAD_DOWN); // D-Pad Down
293 MAP_BUTTON(ImGuiNavInput_FocusPrev, XINPUT_GAMEPAD_LEFT_SHOULDER); // L1 / LB
294 MAP_BUTTON(ImGuiNavInput_FocusNext, XINPUT_GAMEPAD_RIGHT_SHOULDER); // R1 / RB
295 MAP_BUTTON(ImGuiNavInput_TweakSlow, XINPUT_GAMEPAD_LEFT_SHOULDER); // L1 / LB
296 MAP_BUTTON(ImGuiNavInput_TweakFast, XINPUT_GAMEPAD_RIGHT_SHOULDER); // R1 / RB
297 MAP_ANALOG(ImGuiNavInput_LStickLeft, gamepad.sThumbLX, -XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, -32768);
298 MAP_ANALOG(ImGuiNavInput_LStickRight, gamepad.sThumbLX, +XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, +32767);
299 MAP_ANALOG(ImGuiNavInput_LStickUp, gamepad.sThumbLY, +XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, +32767);
300 MAP_ANALOG(ImGuiNavInput_LStickDown, gamepad.sThumbLY, -XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, -32767);
301 #undef MAP_BUTTON
302 #undef MAP_ANALOG
303 }
304 #endif // #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
305 }
306
ImGui_ImplWin32_NewFrame()307 void ImGui_ImplWin32_NewFrame()
308 {
309 ImGuiIO& io = ImGui::GetIO();
310 ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
311 IM_ASSERT(bd != NULL && "Did you call ImGui_ImplWin32_Init()?");
312
313 // Setup display size (every frame to accommodate for window resizing)
314 RECT rect = { 0, 0, 0, 0 };
315 ::GetClientRect(bd->hWnd, &rect);
316 io.DisplaySize = ImVec2((float)(rect.right - rect.left), (float)(rect.bottom - rect.top));
317
318 // Setup time step
319 INT64 current_time = 0;
320 ::QueryPerformanceCounter((LARGE_INTEGER*)¤t_time);
321 io.DeltaTime = (float)(current_time - bd->Time) / bd->TicksPerSecond;
322 bd->Time = current_time;
323
324 // Update OS mouse position
325 ImGui_ImplWin32_UpdateMousePos();
326
327 // Update OS mouse cursor with the cursor requested by imgui
328 ImGuiMouseCursor mouse_cursor = io.MouseDrawCursor ? ImGuiMouseCursor_None : ImGui::GetMouseCursor();
329 if (bd->LastMouseCursor != mouse_cursor)
330 {
331 bd->LastMouseCursor = mouse_cursor;
332 ImGui_ImplWin32_UpdateMouseCursor();
333 }
334
335 // Update game controllers (if enabled and available)
336 ImGui_ImplWin32_UpdateGamepads();
337 }
338
339 // Allow compilation with old Windows SDK. MinGW doesn't have default _WIN32_WINNT/WINVER versions.
340 #ifndef WM_MOUSEHWHEEL
341 #define WM_MOUSEHWHEEL 0x020E
342 #endif
343 #ifndef DBT_DEVNODES_CHANGED
344 #define DBT_DEVNODES_CHANGED 0x0007
345 #endif
346
347 // Win32 message handler (process Win32 mouse/keyboard inputs, etc.)
348 // Call from your application's message handler.
349 // When implementing your own backend, you can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if Dear ImGui wants to use your inputs.
350 // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application.
351 // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application.
352 // Generally you may always pass all inputs to Dear ImGui, and hide them from your application based on those two flags.
353 // 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.
354 // 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.
355 #if 0
356 // Copy this line into your .cpp file to forward declare the function.
357 extern IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
358 #endif
ImGui_ImplWin32_WndProcHandler(HWND hwnd,UINT msg,WPARAM wParam,LPARAM lParam)359 IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
360 {
361 if (ImGui::GetCurrentContext() == NULL)
362 return 0;
363
364 ImGuiIO& io = ImGui::GetIO();
365 ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
366
367 switch (msg)
368 {
369 case WM_MOUSEMOVE:
370 // We need to call TrackMouseEvent in order to receive WM_MOUSELEAVE events
371 bd->MouseHwnd = hwnd;
372 if (!bd->MouseTracked)
373 {
374 TRACKMOUSEEVENT tme = { sizeof(tme), TME_LEAVE, hwnd, 0 };
375 ::TrackMouseEvent(&tme);
376 bd->MouseTracked = true;
377 }
378 break;
379 case WM_MOUSELEAVE:
380 if (bd->MouseHwnd == hwnd)
381 bd->MouseHwnd = NULL;
382 bd->MouseTracked = false;
383 break;
384 case WM_LBUTTONDOWN: case WM_LBUTTONDBLCLK:
385 case WM_RBUTTONDOWN: case WM_RBUTTONDBLCLK:
386 case WM_MBUTTONDOWN: case WM_MBUTTONDBLCLK:
387 case WM_XBUTTONDOWN: case WM_XBUTTONDBLCLK:
388 {
389 int button = 0;
390 if (msg == WM_LBUTTONDOWN || msg == WM_LBUTTONDBLCLK) { button = 0; }
391 if (msg == WM_RBUTTONDOWN || msg == WM_RBUTTONDBLCLK) { button = 1; }
392 if (msg == WM_MBUTTONDOWN || msg == WM_MBUTTONDBLCLK) { button = 2; }
393 if (msg == WM_XBUTTONDOWN || msg == WM_XBUTTONDBLCLK) { button = (GET_XBUTTON_WPARAM(wParam) == XBUTTON1) ? 3 : 4; }
394 if (!ImGui::IsAnyMouseDown() && ::GetCapture() == NULL)
395 ::SetCapture(hwnd);
396 io.MouseDown[button] = true;
397 return 0;
398 }
399 case WM_LBUTTONUP:
400 case WM_RBUTTONUP:
401 case WM_MBUTTONUP:
402 case WM_XBUTTONUP:
403 {
404 int button = 0;
405 if (msg == WM_LBUTTONUP) { button = 0; }
406 if (msg == WM_RBUTTONUP) { button = 1; }
407 if (msg == WM_MBUTTONUP) { button = 2; }
408 if (msg == WM_XBUTTONUP) { button = (GET_XBUTTON_WPARAM(wParam) == XBUTTON1) ? 3 : 4; }
409 io.MouseDown[button] = false;
410 if (!ImGui::IsAnyMouseDown() && ::GetCapture() == hwnd)
411 ::ReleaseCapture();
412 return 0;
413 }
414 case WM_MOUSEWHEEL:
415 io.MouseWheel += (float)GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA;
416 return 0;
417 case WM_MOUSEHWHEEL:
418 io.MouseWheelH += (float)GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA;
419 return 0;
420 case WM_KEYDOWN:
421 case WM_KEYUP:
422 case WM_SYSKEYDOWN:
423 case WM_SYSKEYUP:
424 {
425 bool down = (msg == WM_KEYDOWN || msg == WM_SYSKEYDOWN);
426 if (wParam < 256)
427 io.KeysDown[wParam] = down;
428 if (wParam == VK_CONTROL)
429 io.KeyCtrl = down;
430 if (wParam == VK_SHIFT)
431 io.KeyShift = down;
432 if (wParam == VK_MENU)
433 io.KeyAlt = down;
434 return 0;
435 }
436 case WM_SETFOCUS:
437 case WM_KILLFOCUS:
438 io.AddFocusEvent(msg == WM_SETFOCUS);
439 return 0;
440 case WM_CHAR:
441 // You can also use ToAscii()+GetKeyboardState() to retrieve characters.
442 if (wParam > 0 && wParam < 0x10000)
443 io.AddInputCharacterUTF16((unsigned short)wParam);
444 return 0;
445 case WM_SETCURSOR:
446 if (LOWORD(lParam) == HTCLIENT && ImGui_ImplWin32_UpdateMouseCursor())
447 return 1;
448 return 0;
449 case WM_DEVICECHANGE:
450 if ((UINT)wParam == DBT_DEVNODES_CHANGED)
451 bd->WantUpdateHasGamepad = true;
452 return 0;
453 }
454 return 0;
455 }
456
457
458 //--------------------------------------------------------------------------------------------------------
459 // DPI-related helpers (optional)
460 //--------------------------------------------------------------------------------------------------------
461 // - Use to enable DPI awareness without having to create an application manifest.
462 // - Your own app may already do this via a manifest or explicit calls. This is mostly useful for our examples/ apps.
463 // - In theory we could call simple functions from Windows SDK such as SetProcessDPIAware(), SetProcessDpiAwareness(), etc.
464 // but most of the functions provided by Microsoft require Windows 8.1/10+ SDK at compile time and Windows 8/10+ at runtime,
465 // neither we want to require the user to have. So we dynamically select and load those functions to avoid dependencies.
466 //---------------------------------------------------------------------------------------------------------
467 // This is the scheme successfully used by GLFW (from which we borrowed some of the code) and other apps aiming to be highly portable.
468 // ImGui_ImplWin32_EnableDpiAwareness() is just a helper called by main.cpp, we don't call it automatically.
469 // If you are trying to implement your own backend for your own engine, you may ignore that noise.
470 //---------------------------------------------------------------------------------------------------------
471
472 // Perform our own check with RtlVerifyVersionInfo() instead of using functions from <VersionHelpers.h> as they
473 // require a manifest to be functional for checks above 8.1. See https://github.com/ocornut/imgui/issues/4200
_IsWindowsVersionOrGreater(WORD major,WORD minor,WORD)474 static BOOL _IsWindowsVersionOrGreater(WORD major, WORD minor, WORD)
475 {
476 typedef LONG(WINAPI* PFN_RtlVerifyVersionInfo)(OSVERSIONINFOEXW*, ULONG, ULONGLONG);
477 static PFN_RtlVerifyVersionInfo RtlVerifyVersionInfoFn = NULL;
478 if (RtlVerifyVersionInfoFn == NULL)
479 if (HMODULE ntdllModule = ::GetModuleHandleA("ntdll.dll"))
480 RtlVerifyVersionInfoFn = (PFN_RtlVerifyVersionInfo)GetProcAddress(ntdllModule, "RtlVerifyVersionInfo");
481 if (RtlVerifyVersionInfoFn == NULL)
482 return FALSE;
483
484 RTL_OSVERSIONINFOEXW versionInfo = { };
485 ULONGLONG conditionMask = 0;
486 versionInfo.dwOSVersionInfoSize = sizeof(RTL_OSVERSIONINFOEXW);
487 versionInfo.dwMajorVersion = major;
488 versionInfo.dwMinorVersion = minor;
489 VER_SET_CONDITION(conditionMask, VER_MAJORVERSION, VER_GREATER_EQUAL);
490 VER_SET_CONDITION(conditionMask, VER_MINORVERSION, VER_GREATER_EQUAL);
491 return (RtlVerifyVersionInfoFn(&versionInfo, VER_MAJORVERSION | VER_MINORVERSION, conditionMask) == 0) ? TRUE : FALSE;
492 }
493
494 #define _IsWindowsVistaOrGreater() _IsWindowsVersionOrGreater(HIBYTE(0x0600), LOBYTE(0x0600), 0) // _WIN32_WINNT_VISTA
495 #define _IsWindows8OrGreater() _IsWindowsVersionOrGreater(HIBYTE(0x0602), LOBYTE(0x0602), 0) // _WIN32_WINNT_WIN8
496 #define _IsWindows8Point1OrGreater() _IsWindowsVersionOrGreater(HIBYTE(0x0603), LOBYTE(0x0603), 0) // _WIN32_WINNT_WINBLUE
497 #define _IsWindows10OrGreater() _IsWindowsVersionOrGreater(HIBYTE(0x0A00), LOBYTE(0x0A00), 0) // _WIN32_WINNT_WINTHRESHOLD / _WIN32_WINNT_WIN10
498
499 #ifndef DPI_ENUMS_DECLARED
500 typedef enum { PROCESS_DPI_UNAWARE = 0, PROCESS_SYSTEM_DPI_AWARE = 1, PROCESS_PER_MONITOR_DPI_AWARE = 2 } PROCESS_DPI_AWARENESS;
501 typedef enum { MDT_EFFECTIVE_DPI = 0, MDT_ANGULAR_DPI = 1, MDT_RAW_DPI = 2, MDT_DEFAULT = MDT_EFFECTIVE_DPI } MONITOR_DPI_TYPE;
502 #endif
503 #ifndef _DPI_AWARENESS_CONTEXTS_
504 DECLARE_HANDLE(DPI_AWARENESS_CONTEXT);
505 #define DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE (DPI_AWARENESS_CONTEXT)-3
506 #endif
507 #ifndef DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2
508 #define DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2 (DPI_AWARENESS_CONTEXT)-4
509 #endif
510 typedef HRESULT(WINAPI* PFN_SetProcessDpiAwareness)(PROCESS_DPI_AWARENESS); // Shcore.lib + dll, Windows 8.1+
511 typedef HRESULT(WINAPI* PFN_GetDpiForMonitor)(HMONITOR, MONITOR_DPI_TYPE, UINT*, UINT*); // Shcore.lib + dll, Windows 8.1+
512 typedef DPI_AWARENESS_CONTEXT(WINAPI* PFN_SetThreadDpiAwarenessContext)(DPI_AWARENESS_CONTEXT); // User32.lib + dll, Windows 10 v1607+ (Creators Update)
513
514 // Helper function to enable DPI awareness without setting up a manifest
ImGui_ImplWin32_EnableDpiAwareness()515 void ImGui_ImplWin32_EnableDpiAwareness()
516 {
517 if (_IsWindows10OrGreater())
518 {
519 static HINSTANCE user32_dll = ::LoadLibraryA("user32.dll"); // Reference counted per-process
520 if (PFN_SetThreadDpiAwarenessContext SetThreadDpiAwarenessContextFn = (PFN_SetThreadDpiAwarenessContext)::GetProcAddress(user32_dll, "SetThreadDpiAwarenessContext"))
521 {
522 SetThreadDpiAwarenessContextFn(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
523 return;
524 }
525 }
526 if (_IsWindows8Point1OrGreater())
527 {
528 static HINSTANCE shcore_dll = ::LoadLibraryA("shcore.dll"); // Reference counted per-process
529 if (PFN_SetProcessDpiAwareness SetProcessDpiAwarenessFn = (PFN_SetProcessDpiAwareness)::GetProcAddress(shcore_dll, "SetProcessDpiAwareness"))
530 {
531 SetProcessDpiAwarenessFn(PROCESS_PER_MONITOR_DPI_AWARE);
532 return;
533 }
534 }
535 #if _WIN32_WINNT >= 0x0600
536 ::SetProcessDPIAware();
537 #endif
538 }
539
540 #if defined(_MSC_VER) && !defined(NOGDI)
541 #pragma comment(lib, "gdi32") // Link with gdi32.lib for GetDeviceCaps(). MinGW will require linking with '-lgdi32'
542 #endif
543
ImGui_ImplWin32_GetDpiScaleForMonitor(void * monitor)544 float ImGui_ImplWin32_GetDpiScaleForMonitor(void* monitor)
545 {
546 UINT xdpi = 96, ydpi = 96;
547 if (_IsWindows8Point1OrGreater())
548 {
549 static HINSTANCE shcore_dll = ::LoadLibraryA("shcore.dll"); // Reference counted per-process
550 static PFN_GetDpiForMonitor GetDpiForMonitorFn = NULL;
551 if (GetDpiForMonitorFn == NULL && shcore_dll != NULL)
552 GetDpiForMonitorFn = (PFN_GetDpiForMonitor)::GetProcAddress(shcore_dll, "GetDpiForMonitor");
553 if (GetDpiForMonitorFn != NULL)
554 {
555 GetDpiForMonitorFn((HMONITOR)monitor, MDT_EFFECTIVE_DPI, &xdpi, &ydpi);
556 IM_ASSERT(xdpi == ydpi); // Please contact me if you hit this assert!
557 return xdpi / 96.0f;
558 }
559 }
560 #ifndef NOGDI
561 const HDC dc = ::GetDC(NULL);
562 xdpi = ::GetDeviceCaps(dc, LOGPIXELSX);
563 ydpi = ::GetDeviceCaps(dc, LOGPIXELSY);
564 IM_ASSERT(xdpi == ydpi); // Please contact me if you hit this assert!
565 ::ReleaseDC(NULL, dc);
566 #endif
567 return xdpi / 96.0f;
568 }
569
ImGui_ImplWin32_GetDpiScaleForHwnd(void * hwnd)570 float ImGui_ImplWin32_GetDpiScaleForHwnd(void* hwnd)
571 {
572 HMONITOR monitor = ::MonitorFromWindow((HWND)hwnd, MONITOR_DEFAULTTONEAREST);
573 return ImGui_ImplWin32_GetDpiScaleForMonitor(monitor);
574 }
575
576 //---------------------------------------------------------------------------------------------------------
577 // Transparency related helpers (optional)
578 //--------------------------------------------------------------------------------------------------------
579
580 #if defined(_MSC_VER)
581 #pragma comment(lib, "dwmapi") // Link with dwmapi.lib. MinGW will require linking with '-ldwmapi'
582 #endif
583
584 // [experimental]
585 // Borrowed from GLFW's function updateFramebufferTransparency() in src/win32_window.c
586 // (the Dwm* functions are Vista era functions but we are borrowing logic from GLFW)
ImGui_ImplWin32_EnableAlphaCompositing(void * hwnd)587 void ImGui_ImplWin32_EnableAlphaCompositing(void* hwnd)
588 {
589 if (!_IsWindowsVistaOrGreater())
590 return;
591
592 BOOL composition;
593 if (FAILED(::DwmIsCompositionEnabled(&composition)) || !composition)
594 return;
595
596 BOOL opaque;
597 DWORD color;
598 if (_IsWindows8OrGreater() || (SUCCEEDED(::DwmGetColorizationColor(&color, &opaque)) && !opaque))
599 {
600 HRGN region = ::CreateRectRgn(0, 0, -1, -1);
601 DWM_BLURBEHIND bb = {};
602 bb.dwFlags = DWM_BB_ENABLE | DWM_BB_BLURREGION;
603 bb.hRgnBlur = region;
604 bb.fEnable = TRUE;
605 ::DwmEnableBlurBehindWindow((HWND)hwnd, &bb);
606 ::DeleteObject(region);
607 }
608 else
609 {
610 DWM_BLURBEHIND bb = {};
611 bb.dwFlags = DWM_BB_ENABLE;
612 ::DwmEnableBlurBehindWindow((HWND)hwnd, &bb);
613 }
614 }
615
616 //---------------------------------------------------------------------------------------------------------
617