Backends: Win32/SDL2/SDL3/GLFW: Added support for io.AddMouseSourceEvent(). (#2334, #2702)

SDL doesn't distinguish Pen yet, but we don't need it as much as TouchScreen which will alter trickling.

backends/imgui_impl_glfw.cpp

@@ -5,6 +5,7 @@
 
 // Implemented features:
 //  [X] Platform: Clipboard support.
+//  [X] Platform: Mouse support. Can discriminate Mouse/TouchScreen/Pen (Windows only).
 //  [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 GLFW_KEY_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange' (note: the resizing cursors requires GLFW 3.4+).
@@ -16,6 +17,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-04-04: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_TouchScreen/ImGuiMouseSource_Pen on Windows ONLY, using a custom WndProc hook. (#2702)
 //  2023-03-16: Inputs: Fixed key modifiers handling on secondary viewports (docking branch). Broken on 2023/01/04. (#6248, #6034)
 //  2023-03-14: Emscripten: Avoid using glfwGetError() and glfwGetGamepadState() which are not correctly implemented in Emscripten emulation. (#6240)
 //  2023-02-03: Emscripten: Registering custom low-level mouse wheel handler to get more accurate scrolling impulses on Emscripten. (#4019, #6096)
@@ -127,6 +129,9 @@ struct ImGui_ImplGlfw_Data
     GLFWkeyfun              PrevUserCallbackKey;
     GLFWcharfun             PrevUserCallbackChar;
     GLFWmonitorfun          PrevUserCallbackMonitor;
+#ifdef _WIN32
+    WNDPROC                 GlfwWndProc;
+#endif
 
     ImGui_ImplGlfw_Data()   { memset((void*)this, 0, sizeof(*this)); }
 };
@@ -444,6 +449,35 @@ static EM_BOOL ImGui_ImplEmscripten_WheelCallback(int, const EmscriptenWheelEven
 }
 #endif
 
+#ifdef _WIN32
+// GLFW doesn't allow to distinguish Mouse vs TouchScreen vs Pen.
+// Add support for Win32 (based on imgui_impl_win32), because we rely on _TouchScreen info to trickle inputs differently.
+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;
+}
+static LRESULT CALLBACK ImGui_ImplGlfw_WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    switch (msg)
+    {
+    case WM_MOUSEMOVE: case WM_NCMOUSEMOVE:
+    case WM_LBUTTONDOWN: case WM_LBUTTONDBLCLK: case WM_LBUTTONUP:
+    case WM_RBUTTONDOWN: case WM_RBUTTONDBLCLK: case WM_RBUTTONUP:
+    case WM_MBUTTONDOWN: case WM_MBUTTONDBLCLK: case WM_MBUTTONUP:
+    case WM_XBUTTONDOWN: case WM_XBUTTONDBLCLK: case WM_XBUTTONUP:
+        ImGui::GetIO().AddMouseSourceEvent(GetMouseSourceFromMessageExtraInfo());
+        break;
+    }
+    return ::CallWindowProc(bd->GlfwWndProc, hWnd, msg, wParam, lParam);
+}
+#endif
+
 void ImGui_ImplGlfw_InstallCallbacks(GLFWwindow* window)
 {
     ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
@@ -562,6 +596,13 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
     IM_UNUSED(main_viewport);
 #endif
 
+    // Windows: register a WndProc hook so we can intercept some messages.
+#ifdef _WIN32
+    bd->GlfwWndProc = (WNDPROC)::GetWindowLongPtr((HWND)main_viewport->PlatformHandleRaw, GWLP_WNDPROC);
+    IM_ASSERT(bd->GlfwWndProc != NULL);
+    ::SetWindowLongPtr((HWND)main_viewport->PlatformHandleRaw, GWLP_WNDPROC, (LONG_PTR)ImGui_ImplGlfw_WndProc);
+#endif
+
     bd->ClientApi = client_api;
     return true;
 }
@@ -593,6 +634,13 @@ void ImGui_ImplGlfw_Shutdown()
     for (ImGuiMouseCursor cursor_n = 0; cursor_n < ImGuiMouseCursor_COUNT; cursor_n++)
         glfwDestroyCursor(bd->MouseCursors[cursor_n]);
 
+    // Windows: register a WndProc hook so we can intercept some messages.
+#ifdef _WIN32
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ::SetWindowLongPtr((HWND)main_viewport->PlatformHandleRaw, GWLP_WNDPROC, (LONG_PTR)bd->GlfwWndProc);
+    bd->GlfwWndProc = NULL;
+#endif
+
     io.BackendPlatformName = nullptr;
     io.BackendPlatformUserData = nullptr;
     IM_DELETE(bd);

backends/imgui_impl_glfw.h

@@ -4,6 +4,7 @@
 
 // Implemented features:
 //  [X] Platform: Clipboard support.
+//  [X] Platform: Mouse support. Can discriminate Mouse/TouchScreen/Pen (Windows only).
 //  [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 GLFW_KEY_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange' (note: the resizing cursors requires GLFW 3.4+).

backends/imgui_impl_sdl2.cpp

@@ -5,6 +5,7 @@
 
 // Implemented features:
 //  [X] Platform: Clipboard support.
+//  [X] Platform: Mouse support. Can discriminate Mouse/TouchScreen.
 //  [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 SDL_SCANCODE_* 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'.
@@ -17,6 +18,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-04-04: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_TouchScreen. (#2702)
 //  2023-02-23: Accept SDL_GetPerformanceCounter() not returning a monotonically increasing value. (#6189, #6114, #3644)
 //  2023-02-07: Implement IME handler (io.SetPlatformImeDataFn will call SDL_SetTextInputRect()/SDL_StartTextInput()).
 //  2023-02-07: *BREAKING CHANGE* Renamed this backend file from imgui_impl_sdl.cpp/.h to imgui_impl_sdl2.cpp/.h in prevision for the future release of SDL3.
@@ -289,6 +291,7 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
         case SDL_MOUSEMOTION:
         {
             ImVec2 mouse_pos((float)event->motion.x, (float)event->motion.y);
+            io.AddMouseSourceEvent(event->motion.which == SDL_TOUCH_MOUSEID ? ImGuiMouseSource_TouchScreen : ImGuiMouseSource_Mouse);
             io.AddMousePosEvent(mouse_pos.x, mouse_pos.y);
             return true;
         }
@@ -305,6 +308,7 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
 #ifdef __EMSCRIPTEN__
             wheel_x /= 100.0f;
 #endif
+            io.AddMouseSourceEvent(event->wheel.which == SDL_TOUCH_MOUSEID ? ImGuiMouseSource_TouchScreen : ImGuiMouseSource_Mouse);
             io.AddMouseWheelEvent(wheel_x, wheel_y);
             return true;
         }
@@ -319,6 +323,7 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
             if (event->button.button == SDL_BUTTON_X2) { mouse_button = 4; }
             if (mouse_button == -1)
                 break;
+            io.AddMouseSourceEvent(event->button.which == SDL_TOUCH_MOUSEID ? ImGuiMouseSource_TouchScreen : ImGuiMouseSource_Mouse);
             io.AddMouseButtonEvent(mouse_button, (event->type == SDL_MOUSEBUTTONDOWN));
             bd->MouseButtonsDown = (event->type == SDL_MOUSEBUTTONDOWN) ? (bd->MouseButtonsDown | (1 << mouse_button)) : (bd->MouseButtonsDown & ~(1 << mouse_button));
             return true;

backends/imgui_impl_sdl2.h

@@ -4,6 +4,7 @@
 
 // Implemented features:
 //  [X] Platform: Clipboard support.
+//  [X] Platform: Mouse support. Can discriminate Mouse/TouchScreen.
 //  [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 SDL_SCANCODE_* 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'.

backends/imgui_impl_sdl3.cpp

@@ -5,6 +5,7 @@
 
 // Implemented features:
 //  [X] Platform: Clipboard support.
+//  [X] Platform: Mouse support. Can discriminate Mouse/TouchScreen.
 //  [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 SDL_SCANCODE_* 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'.
@@ -18,6 +19,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-04-04: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_TouchScreen. (#2702)
 //  2023-02-23: Accept SDL_GetPerformanceCounter() not returning a monotonically increasing value. (#6189, #6114, #3644)
 //  2023-02-07: Forked "imgui_impl_sdl2" into "imgui_impl_sdl3". Removed version checks for old feature. Refer to imgui_impl_sdl2.cpp for older changelog.
 
@@ -239,6 +241,7 @@ bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
         case SDL_EVENT_MOUSE_MOTION:
         {
             ImVec2 mouse_pos((float)event->motion.x, (float)event->motion.y);
+            io.AddMouseSourceEvent(event->motion.which == SDL_TOUCH_MOUSEID ? ImGuiMouseSource_TouchScreen : ImGuiMouseSource_Mouse);
             io.AddMousePosEvent(mouse_pos.x, mouse_pos.y);
             return true;
         }
@@ -250,6 +253,7 @@ bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
     #ifdef __EMSCRIPTEN__
             wheel_x /= 100.0f;
     #endif
+            io.AddMouseSourceEvent(event->wheel.which == SDL_TOUCH_MOUSEID ? ImGuiMouseSource_TouchScreen : ImGuiMouseSource_Mouse);
             io.AddMouseWheelEvent(wheel_x, wheel_y);
             return true;
         }
@@ -264,6 +268,7 @@ bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
             if (event->button.button == SDL_BUTTON_X2) { mouse_button = 4; }
             if (mouse_button == -1)
                 break;
+            io.AddMouseSourceEvent(event->button.which == SDL_TOUCH_MOUSEID ? ImGuiMouseSource_TouchScreen : ImGuiMouseSource_Mouse);
             io.AddMouseButtonEvent(mouse_button, (event->type == SDL_EVENT_MOUSE_BUTTON_DOWN));
             bd->MouseButtonsDown = (event->type == SDL_EVENT_MOUSE_BUTTON_DOWN) ? (bd->MouseButtonsDown | (1 << mouse_button)) : (bd->MouseButtonsDown & ~(1 << mouse_button));
             return true;
@@ -368,7 +373,7 @@ static bool ImGui_ImplSDL3_Init(SDL_Window* window, SDL_Renderer* renderer)
     // Without this, when clicking to gain focus, our widgets wouldn't activate even though they showed as hovered.
     // (This is unfortunately a global SDL setting, so enabling it might have a side-effect on your application.
     // It is unlikely to make a difference, but if your app absolutely needs to ignore the initial on-focus click:
-    // you can ignore SDL_MOUSEBUTTONDOWN events coming right after a SDL_WINDOWEVENT_FOCUS_GAINED)
+    // you can ignore SDL_EVENT_MOUSE_BUTTON_DOWN events coming right after a SDL_WINDOWEVENT_FOCUS_GAINED)
 #ifdef SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH
     SDL_SetHint(SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH, "1");
 #endif
@@ -432,7 +437,7 @@ static void ImGui_ImplSDL3_UpdateMouseData()
     ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
     ImGuiIO& io = ImGui::GetIO();
 
-    // We forward mouse input when hovered or captured (via SDL_MOUSEMOTION) or when focused (below)
+    // We forward mouse input when hovered or captured (via SDL_EVENT_MOUSE_MOTION) or when focused (below)
 #if SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE
     // SDL_CaptureMouse() let the OS know e.g. that our imgui drag outside the SDL window boundaries shouldn't e.g. trigger other operations outside
     SDL_CaptureMouse((bd->MouseButtonsDown != 0) ? SDL_TRUE : SDL_FALSE);
@@ -447,7 +452,7 @@ static void ImGui_ImplSDL3_UpdateMouseData()
         if (io.WantSetMousePos)
             SDL_WarpMouseInWindow(bd->Window, io.MousePos.x, io.MousePos.y);
 
-        // (Optional) Fallback to provide mouse position when focused (SDL_MOUSEMOTION already provides this when hovered or captured)
+        // (Optional) Fallback to provide mouse position when focused (SDL_EVENT_MOUSE_MOTION already provides this when hovered or captured)
         if (bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0)
         {
             // 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)

backends/imgui_impl_sdl3.h

@@ -5,6 +5,7 @@
 
 // Implemented features:
 //  [X] Platform: Clipboard support.
+//  [X] Platform: Mouse support. Can discriminate Mouse/TouchScreen.
 //  [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 SDL_SCANCODE_* 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'.

backends/imgui_impl_win32.cpp

@@ -3,6 +3,7 @@
 
 // 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'.
@@ -34,6 +35,7 @@ typedef DWORD (WINAPI *PFN_XInputGetState)(DWORD, XINPUT_STATE*);
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  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.
@@ -506,6 +508,19 @@ static ImGuiKey ImGui_ImplWin32_VirtualKeyToImGuiKey(WPARAM wParam)
 // 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);
 #endif
+
+// See https://learn.microsoft.com/en-us/windows/win32/tablet/system-events-and-mouse-messages
+// 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)
 {
     if (ImGui::GetCurrentContext() == nullptr)
@@ -520,6 +535,7 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
     case WM_NCMOUSEMOVE:
     {
         // 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)
@@ -534,6 +550,7 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
         POINT mouse_pos = { (LONG)GET_X_LPARAM(lParam), (LONG)GET_Y_LPARAM(lParam) };
         if (msg == WM_NCMOUSEMOVE && ::ScreenToClient(hwnd, &mouse_pos) == FALSE) // WM_NCMOUSEMOVE are provided in absolute coordinates.
             break;
+        io.AddMouseSourceEvent(mouse_source);
         io.AddMousePosEvent((float)mouse_pos.x, (float)mouse_pos.y);
         break;
     }
@@ -555,6 +572,7 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
     case WM_MBUTTONDOWN: case WM_MBUTTONDBLCLK:
     case WM_XBUTTONDOWN: case WM_XBUTTONDBLCLK:
     {
+        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; }
@@ -563,6 +581,7 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
         if (bd->MouseButtonsDown == 0 && ::GetCapture() == nullptr)
             ::SetCapture(hwnd);
         bd->MouseButtonsDown |= 1 << button;
+        io.AddMouseSourceEvent(mouse_source);
         io.AddMouseButtonEvent(button, true);
         return 0;
     }
@@ -571,6 +590,7 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
     case WM_MBUTTONUP:
     case WM_XBUTTONUP:
     {
+        ImGuiMouseSource mouse_source = GetMouseSourceFromMessageExtraInfo();
         int button = 0;
         if (msg == WM_LBUTTONUP) { button = 0; }
         if (msg == WM_RBUTTONUP) { button = 1; }
@@ -579,6 +599,7 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
         bd->MouseButtonsDown &= ~(1 << button);
         if (bd->MouseButtonsDown == 0 && ::GetCapture() == hwnd)
             ::ReleaseCapture();
+        io.AddMouseSourceEvent(mouse_source);
         io.AddMouseButtonEvent(button, false);
         return 0;
     }

backends/imgui_impl_win32.h

@@ -3,6 +3,7 @@
 
 // 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'.

docs/CHANGELOG.txt

@@ -65,6 +65,11 @@ Other changes:
 - Backends: OpenGL3: Fixed GL loader crash when GL_VERSION returns NULL. (#6154, #4445, #3530)
 - Backends: OpenGL3: Properly restoring "no shader program bound" if it was the case prior to
   running the rendering function. (#6267, #6220, #6224) [@BrunoLevy]
+- Backends: Win32: Added support for io.AddMouseSourceEvent() to discriminate Mouse/TouchScreen/Pen. (#2334, #2702)
+- Backends: SDL2/SDL3: Added support for io.AddMouseSourceEvent() to discriminate Mouse/TouchScreen.
+  This is relying on SDL passing SDL_TOUCH_MOUSEID in the event's 'which' field. (#2334, #2702)
+- Backends: GLFW: Added support on Win32 only for io.AddMouseSourceEvent() to discriminate
+  Mouse/TouchScreen/Pen. (#2334, #2702)
 - Backends: GLFW: Fixed key modifiers handling on secondary viewports. (#6248, #6034) [@aiekick]
 - Examples: Windows: Added 'misc/debuggers/imgui.natstepfilter' file to all Visual Studio projects,
   now that VS 2022 17.6 Preview 2 support adding Debug Step Filter spec files into projects.