IO: Added AddMousePosEvent(), AddMouseButtonEvent(), AddMouseWheelEvent() api + updated all Backends. (#4858) (input queue code will be next commit)

Details: note that SDL, OSX and GLFW backends removed recording of MouseJustPressed[] which will be unnecessary with input queue (which is the NEXT commit). (#2787, #1992, #3383, #2525, #1320)

backends/imgui_impl_allegro5.cpp

@@ -17,6 +17,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2022-01-17: Inputs: calling new io.AddMousePosEvent(), io.AddMouseButtonEvent(), io.AddMouseWheelEvent() API (1.87+).
 //  2022-01-17: Inputs: always calling io.AddKeyModsEvent() next and before key event (not in NewFrame) to fix input queue with very low framerates.
 //  2022-01-10: Inputs: calling new io.AddKeyEvent(), io.AddKeyModsEvent() + io.SetKeyEventNativeData() API (1.87+). Support for full ImGuiKey range.
 //  2021-12-08: Renderer: Fixed mishandling of the the ImDrawCmd::IdxOffset field! This is an old bug but it never had an effect until some internal rendering changes in 1.86.
@@ -469,29 +470,28 @@ bool ImGui_ImplAllegro5_ProcessEvent(ALLEGRO_EVENT* ev)
     case ALLEGRO_EVENT_MOUSE_AXES:
         if (ev->mouse.display == bd->Display)
         {
-            io.MouseWheel += ev->mouse.dz;
-            io.MouseWheelH -= ev->mouse.dw;
-            io.MousePos = ImVec2(ev->mouse.x, ev->mouse.y);
+            io.AddMousePosEvent(ev->mouse.x, ev->mouse.y);
+            io.AddMouseWheelEvent(-ev->mouse.dw, ev->mouse.dz);
         }
         return true;
     case ALLEGRO_EVENT_MOUSE_BUTTON_DOWN:
     case ALLEGRO_EVENT_MOUSE_BUTTON_UP:
-        if (ev->mouse.display == bd->Display && ev->mouse.button <= 5)
-            io.MouseDown[ev->mouse.button - 1] = (ev->type == ALLEGRO_EVENT_MOUSE_BUTTON_DOWN);
+        if (ev->mouse.display == bd->Display && ev->mouse.button > 0 && ev->mouse.button <= 5)
+            io.AddMouseButtonEvent(ev->mouse.button - 1, ev->type == ALLEGRO_EVENT_MOUSE_BUTTON_DOWN);
         return true;
     case ALLEGRO_EVENT_TOUCH_MOVE:
         if (ev->touch.display == bd->Display)
-            io.MousePos = ImVec2(ev->touch.x, ev->touch.y);
+            io.AddMousePosEvent(ev->touch.x, ev->touch.y);
         return true;
     case ALLEGRO_EVENT_TOUCH_BEGIN:
     case ALLEGRO_EVENT_TOUCH_END:
     case ALLEGRO_EVENT_TOUCH_CANCEL:
         if (ev->touch.display == bd->Display && ev->touch.primary)
-            io.MouseDown[0] = (ev->type == ALLEGRO_EVENT_TOUCH_BEGIN);
+            io.AddMouseButtonEvent(0, ev->type == ALLEGRO_EVENT_TOUCH_BEGIN);
         return true;
     case ALLEGRO_EVENT_MOUSE_LEAVE_DISPLAY:
         if (ev->mouse.display == bd->Display)
-            io.MousePos = ImVec2(-FLT_MAX, -FLT_MAX);
+            io.AddMousePosEvent(-FLT_MAX, -FLT_MAX);
         return true;
     case ALLEGRO_EVENT_KEY_CHAR:
         if (ev->keyboard.display == bd->Display)

backends/imgui_impl_android.cpp

@@ -19,6 +19,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2022-01-17: Inputs: calling new io.AddMousePosEvent(), io.AddMouseButtonEvent(), io.AddMouseWheelEvent() API (1.87+).
 //  2022-01-10: Inputs: calling new io.AddKeyEvent(), io.AddKeyModsEvent() + io.SetKeyEventNativeData() API (1.87+). Support for full ImGuiKey range.
 //  2021-03-04: Initial version.
 
@@ -227,26 +228,25 @@ int32_t ImGui_ImplAndroid_HandleInputEvent(AInputEvent* input_event)
             if((AMotionEvent_getToolType(input_event, event_pointer_index) == AMOTION_EVENT_TOOL_TYPE_FINGER)
             || (AMotionEvent_getToolType(input_event, event_pointer_index) == AMOTION_EVENT_TOOL_TYPE_UNKNOWN))
             {
-                io.MouseDown[0] = (event_action == AMOTION_EVENT_ACTION_DOWN);
-                io.MousePos = ImVec2(AMotionEvent_getX(input_event, event_pointer_index), AMotionEvent_getY(input_event, event_pointer_index));
+                io.AddMousePosEvent(AMotionEvent_getX(input_event, event_pointer_index), AMotionEvent_getY(input_event, event_pointer_index));
+                io.AddMouseButtonEvent(0, event_action == AMOTION_EVENT_ACTION_DOWN);
             }
             break;
         case AMOTION_EVENT_ACTION_BUTTON_PRESS:
         case AMOTION_EVENT_ACTION_BUTTON_RELEASE:
             {
                 int32_t button_state = AMotionEvent_getButtonState(input_event);
-                io.MouseDown[0] = ((button_state & AMOTION_EVENT_BUTTON_PRIMARY) != 0);
-                io.MouseDown[1] = ((button_state & AMOTION_EVENT_BUTTON_SECONDARY) != 0);
-                io.MouseDown[2] = ((button_state & AMOTION_EVENT_BUTTON_TERTIARY) != 0);
+                io.AddMouseButtonEvent(0, (button_state & AMOTION_EVENT_BUTTON_PRIMARY) != 0);
+                io.AddMouseButtonEvent(1, (button_state & AMOTION_EVENT_BUTTON_SECONDARY) != 0);
+                io.AddMouseButtonEvent(2, (button_state & AMOTION_EVENT_BUTTON_TERTIARY) != 0);
             }
             break;
         case AMOTION_EVENT_ACTION_HOVER_MOVE: // Hovering: Tool moves while NOT pressed (such as a physical mouse)
         case AMOTION_EVENT_ACTION_MOVE:       // Touch pointer moves while DOWN
-            io.MousePos = ImVec2(AMotionEvent_getX(input_event, event_pointer_index), AMotionEvent_getY(input_event, event_pointer_index));
+            io.AddMousePosEvent(AMotionEvent_getX(input_event, event_pointer_index), AMotionEvent_getY(input_event, event_pointer_index));
             break;
         case AMOTION_EVENT_ACTION_SCROLL:
-            io.MouseWheel = AMotionEvent_getAxisValue(input_event, AMOTION_EVENT_AXIS_VSCROLL, event_pointer_index);
-            io.MouseWheelH = AMotionEvent_getAxisValue(input_event, AMOTION_EVENT_AXIS_HSCROLL, event_pointer_index);
+            io.AddMouseWheelEvent(AMotionEvent_getAxisValue(input_event, AMOTION_EVENT_AXIS_HSCROLL, event_pointer_index), AMotionEvent_getAxisValue(input_event, AMOTION_EVENT_AXIS_VSCROLL, event_pointer_index));
             break;
         default:
             break;

backends/imgui_impl_glfw.cpp

@@ -16,6 +16,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2022-01-17: Inputs: calling new io.AddMousePosEvent(), io.AddMouseButtonEvent(), io.AddMouseWheelEvent() API (1.87+).
 //  2022-01-17: Inputs: always calling io.AddKeyModsEvent() next and before key event (not in NewFrame) to fix input queue with very low framerates.
 //  2022-01-12: *BREAKING CHANGE*: Now using glfwSetCursorPosCallback(). If you called ImGui_ImplGlfw_InitXXX() with install_callbacks = false, you MUST install glfwSetCursorPosCallback() and forward it to the backend via ImGui_ImplGlfw_CursorPosCallback().
 //  2022-01-10: Inputs: calling new io.AddKeyEvent(), io.AddKeyModsEvent() + io.SetKeyEventNativeData() API (1.87+). Support for full ImGuiKey range.
@@ -86,7 +87,6 @@ struct ImGui_ImplGlfw_Data
     GlfwClientApi           ClientApi;
     double                  Time;
     GLFWwindow*             MouseWindow;
-    bool                    MouseJustPressed[ImGuiMouseButton_COUNT];
     GLFWcursor*             MouseCursors[ImGuiMouseCursor_COUNT];
     bool                    InstalledCallbacks;
 
@@ -257,8 +257,10 @@ void ImGui_ImplGlfw_MouseButtonCallback(GLFWwindow* window, int button, int acti
         bd->PrevUserCallbackMousebutton(window, button, action, mods);
 
     ImGui_ImplGlfw_UpdateKeyModifiers(mods);
-    if (action == GLFW_PRESS && button >= 0 && button < IM_ARRAYSIZE(bd->MouseJustPressed))
-        bd->MouseJustPressed[button] = true;
+
+    ImGuiIO& io = ImGui::GetIO();
+    if (button >= 0 && button < ImGuiMouseButton_COUNT)
+        io.AddMouseButtonEvent(button, action == GLFW_PRESS);
 }
 
 void ImGui_ImplGlfw_ScrollCallback(GLFWwindow* window, double xoffset, double yoffset)
@@ -268,8 +270,7 @@ void ImGui_ImplGlfw_ScrollCallback(GLFWwindow* window, double xoffset, double yo
         bd->PrevUserCallbackScroll(window, xoffset, yoffset);
 
     ImGuiIO& io = ImGui::GetIO();
-    io.MouseWheelH += (float)xoffset;
-    io.MouseWheel += (float)yoffset;
+    io.AddMouseWheelEvent((float)xoffset, (float)yoffset);
 }
 
 static int ImGui_ImplGlfw_TranslateUntranslatedKey(int key, int scancode)
@@ -333,7 +334,7 @@ void ImGui_ImplGlfw_CursorPosCallback(GLFWwindow* window, double x, double y)
         bd->PrevUserCallbackCursorPos(window, x, y);
 
     ImGuiIO& io = ImGui::GetIO();
-    io.MousePos = ImVec2((float)x, (float)y);
+    io.AddMousePosEvent((float)x, (float)y);
 }
 
 void ImGui_ImplGlfw_CursorEnterCallback(GLFWwindow* window, int entered)
@@ -348,7 +349,7 @@ void ImGui_ImplGlfw_CursorEnterCallback(GLFWwindow* window, int entered)
     if (!entered && bd->MouseWindow == window)
     {
         bd->MouseWindow = NULL;
-        io.MousePos = ImVec2(-FLT_MAX, -FLT_MAX);
+        io.AddMousePosEvent(-FLT_MAX, -FLT_MAX);
     }
 }
 
@@ -501,16 +502,9 @@ static void ImGui_ImplGlfw_UpdateMouseData()
         {
             double mouse_x, mouse_y;
             glfwGetCursorPos(bd->Window, &mouse_x, &mouse_y);
-            io.MousePos = ImVec2((float)mouse_x, (float)mouse_y);
+            io.AddMousePosEvent((float)mouse_x, (float)mouse_y);
         }
     }
-
-    // Update buttons
-    for (int i = 0; i < IM_ARRAYSIZE(io.MouseDown); i++)
-    {
-        io.MouseDown[i] = bd->MouseJustPressed[i] || glfwGetMouseButton(bd->Window, i) != 0;
-        bd->MouseJustPressed[i] = false;
-    }
 }
 
 static void ImGui_ImplGlfw_UpdateMouseCursor()

backends/imgui_impl_glut.cpp

@@ -20,6 +20,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2022-01-17: Inputs: calling new io.AddMousePosEvent(), io.AddMouseButtonEvent(), io.AddMouseWheelEvent() API (1.87+).
 //  2022-01-10: Inputs: calling new io.AddKeyEvent(), io.AddKeyModsEvent() + io.SetKeyEventNativeData() API (1.87+). Support for full ImGuiKey range.
 //  2019-04-03: Misc: Renamed imgui_impl_freeglut.cpp/.h to imgui_impl_glut.cpp/.h.
 //  2019-03-25: Misc: Made io.DeltaTime always above zero.
@@ -264,26 +265,22 @@ void ImGui_ImplGLUT_SpecialUpFunc(int key, int x, int y)
 void ImGui_ImplGLUT_MouseFunc(int glut_button, int state, int x, int y)
 {
     ImGuiIO& io = ImGui::GetIO();
-    io.MousePos = ImVec2((float)x, (float)y);
+    io.AddMousePosEvent((float)x, (float)y);
     int button = -1;
     if (glut_button == GLUT_LEFT_BUTTON) button = 0;
     if (glut_button == GLUT_RIGHT_BUTTON) button = 1;
     if (glut_button == GLUT_MIDDLE_BUTTON) button = 2;
-    if (button != -1 && state == GLUT_DOWN)
-        io.MouseDown[button] = true;
-    if (button != -1 && state == GLUT_UP)
-        io.MouseDown[button] = false;
+    if (button != -1 && state == GLUT_DOWN || state == GLUT_UP)
+        io.AddMouseButtonEvent(button, state == GLUT_DOWN);
 }
 
 #ifdef __FREEGLUT_EXT_H__
 void ImGui_ImplGLUT_MouseWheelFunc(int button, int dir, int x, int y)
 {
     ImGuiIO& io = ImGui::GetIO();
-    io.MousePos = ImVec2((float)x, (float)y);
-    if (dir > 0)
-        io.MouseWheel += 1.0;
-    else if (dir < 0)
-        io.MouseWheel -= 1.0;
+    io.AddMousePosEvent((float)x, (float)y);
+    if (dir != 0)
+        io.AddMouseWheelEvent(0.0f, dir > 0 ? 1.0f : -1.0f);
     (void)button; // Unused
 }
 #endif
@@ -297,5 +294,5 @@ void ImGui_ImplGLUT_ReshapeFunc(int w, int h)
 void ImGui_ImplGLUT_MotionFunc(int x, int y)
 {
     ImGuiIO& io = ImGui::GetIO();
-    io.MousePos = ImVec2((float)x, (float)y);
+    io.AddMousePosEvent((float)x, (float)y);
 }

backends/imgui_impl_osx.mm

@@ -23,6 +23,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2022-01-17: Inputs: calling new io.AddMousePosEvent(), io.AddMouseButtonEvent(), io.AddMouseWheelEvent() API (1.87+).
 //  2022-01-12: Inputs: Added basic Platform IME support, hooking the io.SetPlatformImeDataFn() function.
 //  2022-01-10: Inputs: calling new io.AddKeyEvent(), io.AddKeyModsEvent() + io.SetKeyEventNativeData() API (1.87+). Support for full ImGuiKey range.
 //  2021-12-13: *BREAKING CHANGE* Add NSView parameter to ImGui_ImplOSX_Init(). Generally fix keyboard support. Using kVK_* codes for keyboard keys.
@@ -51,8 +52,6 @@ static double               g_HostClockPeriod = 0.0;
 static double               g_Time = 0.0;
 static NSCursor*            g_MouseCursors[ImGuiMouseCursor_COUNT] = {};
 static bool                 g_MouseCursorHidden = false;
-static bool                 g_MouseJustPressed[ImGuiMouseButton_COUNT] = {};
-static bool                 g_MouseDown[ImGuiMouseButton_COUNT] = {};
 static ImFocusObserver*     g_FocusObserver = nil;
 static KeyEventResponder*   g_KeyEventResponder = nil;
 static NSTextInputContext*  g_InputContext = nil;
@@ -450,17 +449,9 @@ void ImGui_ImplOSX_Shutdown()
     g_FocusObserver = NULL;
 }
 
-static void ImGui_ImplOSX_UpdateMouseCursorAndButtons()
+static void ImGui_ImplOSX_UpdateMouseCursor()
 {
-    // Update buttons
     ImGuiIO& io = ImGui::GetIO();
-    for (int i = 0; i < IM_ARRAYSIZE(io.MouseDown); i++)
-    {
-        // If a mouse press event came, always pass it as "mouse held this frame", so we don't miss click-release events that are shorter than 1 frame.
-        io.MouseDown[i] = g_MouseJustPressed[i] || g_MouseDown[i];
-        g_MouseJustPressed[i] = false;
-    }
-
     if (io.ConfigFlags & ImGuiConfigFlags_NoMouseCursorChange)
         return;
 
@@ -562,7 +553,7 @@ void ImGui_ImplOSX_NewFrame(NSView* view)
     io.DeltaTime = (float)(current_time - g_Time);
     g_Time = current_time;
 
-    ImGui_ImplOSX_UpdateMouseCursorAndButtons();
+    ImGui_ImplOSX_UpdateMouseCursor();
     ImGui_ImplOSX_UpdateGamepads();
     ImGui_ImplOSX_UpdateImePosWithView(view);
 }
@@ -574,16 +565,16 @@ bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view)
     if (event.type == NSEventTypeLeftMouseDown || event.type == NSEventTypeRightMouseDown || event.type == NSEventTypeOtherMouseDown)
     {
         int button = (int)[event buttonNumber];
-        if (button >= 0 && button < IM_ARRAYSIZE(g_MouseDown))
-            g_MouseDown[button] = g_MouseJustPressed[button] = true;
+        if (button >= 0 && button < ImGuiMouseButton_COUNT)
+            io.AddMouseButtonEvent(button, true);
         return io.WantCaptureMouse;
     }
 
     if (event.type == NSEventTypeLeftMouseUp || event.type == NSEventTypeRightMouseUp || event.type == NSEventTypeOtherMouseUp)
     {
         int button = (int)[event buttonNumber];
-        if (button >= 0 && button < IM_ARRAYSIZE(g_MouseDown))
-            g_MouseDown[button] = false;
+        if (button >= 0 && button < ImGuiMouseButton_COUNT)
+            io.AddMouseButtonEvent(button, false);
         return io.WantCaptureMouse;
     }
 
@@ -592,7 +583,7 @@ bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view)
         NSPoint mousePoint = event.locationInWindow;
         mousePoint = [view convertPoint:mousePoint fromView:nil];
         mousePoint = NSMakePoint(mousePoint.x, view.bounds.size.height - mousePoint.y);
-        io.MousePos = ImVec2((float)mousePoint.x, (float)mousePoint.y);
+        io.AddMousePosEvent((float)mousePoint.x, (float)mousePoint.y);
     }
 
     if (event.type == NSEventTypeScrollWheel)
@@ -632,11 +623,9 @@ bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view)
             wheel_dx = [event deltaX];
             wheel_dy = [event deltaY];
         }
+        if (wheel_dx != 0.0 || wheel_dx != 0.0)
+            io.AddMouseWheelEvent((float)wheel_dx * 0.1f, (float)wheel_dy * 0.1f);
 
-        if (fabs(wheel_dx) > 0.0)
-            io.MouseWheelH += (float)wheel_dx * 0.1f;
-        if (fabs(wheel_dy) > 0.0)
-            io.MouseWheel += (float)wheel_dy * 0.1f;
         return io.WantCaptureMouse;
     }
 

backends/imgui_impl_sdl.cpp

@@ -18,6 +18,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2022-01-17: Inputs: calling new io.AddMousePosEvent(), io.AddMouseButtonEvent(), io.AddMouseWheelEvent() API (1.87+).
 //  2022-01-17: Inputs: always calling io.AddKeyModsEvent() next and before key event (not in NewFrame) to fix input queue with very low framerates.
 //  2022-01-12: Update mouse inputs using SDL_MOUSEMOTION/SDL_WINDOWEVENT_LEAVE + 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: Maintain our own copy of MouseButtonsDown mask instead of using ImGui::IsAnyMouseDown() which will be obsoleted.
@@ -78,7 +79,6 @@ struct ImGui_ImplSDL2_Data
     SDL_Window* Window;
     Uint64      Time;
     int         MouseButtonsDown;
-    bool        MousePressed[3];
     SDL_Cursor* MouseCursors[ImGuiMouseCursor_COUNT];
     char*       ClipboardTextData;
     bool        MouseCanUseGlobalState;
@@ -248,15 +248,14 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
     {
         case SDL_MOUSEMOTION:
         {
-            io.MousePos = ImVec2((float)event->motion.x, (float)event->motion.y);
+            io.AddMousePosEvent((float)event->motion.x, (float)event->motion.y);
             return true;
         }
         case SDL_MOUSEWHEEL:
         {
-            if (event->wheel.x > 0) io.MouseWheelH += 1;
-            if (event->wheel.x < 0) io.MouseWheelH -= 1;
-            if (event->wheel.y > 0) io.MouseWheel += 1;
-            if (event->wheel.y < 0) io.MouseWheel -= 1;
+            float wheel_x = (event->wheel.x > 0) ? 1.0f : (event->wheel.x < 0) ? -1.0f : 0.0f;
+            float wheel_y = (event->wheel.y > 0) ? 1.0f : (event->wheel.y < 0) ? -1.0f : 0.0f;
+            io.AddMouseWheelEvent(wheel_x, wheel_y);
             return true;
         }
         case SDL_MOUSEBUTTONDOWN:
@@ -268,8 +267,7 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
             if (event->button.button == SDL_BUTTON_MIDDLE) { mouse_button = 2; }
             if (mouse_button == -1)
                 break;
-            if (event->type == SDL_MOUSEBUTTONDOWN)
-                bd->MousePressed[mouse_button] = true;
+            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;
         }
@@ -290,7 +288,7 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
         case SDL_WINDOWEVENT:
         {
             if (event->window.event == SDL_WINDOWEVENT_LEAVE)
-                io.MousePos = ImVec2(-FLT_MAX, -FLT_MAX);
+                io.AddMousePosEvent(-FLT_MAX, -FLT_MAX);
             if (event->window.event == SDL_WINDOWEVENT_FOCUS_GAINED)
                 io.AddFocusEvent(true);
             else if (event->window.event == SDL_WINDOWEVENT_FOCUS_LOST)
@@ -438,16 +436,9 @@ static void ImGui_ImplSDL2_UpdateMouseData()
             int window_x, window_y, mouse_x_global, mouse_y_global;
             SDL_GetGlobalMouseState(&mouse_x_global, &mouse_y_global);
             SDL_GetWindowPosition(bd->Window, &window_x, &window_y);
-            io.MousePos = ImVec2((float)(mouse_x_global - window_x), (float)(mouse_y_global - window_y));
+            io.AddMousePosEvent((float)(mouse_x_global - window_x), (float)(mouse_y_global - window_y));
         }
     }
-
-    // Update buttons
-    Uint32 mouse_buttons = SDL_GetMouseState(NULL, NULL);
-    io.MouseDown[0] = bd->MousePressed[0] || (mouse_buttons & SDL_BUTTON(SDL_BUTTON_LEFT)) != 0;  // If a mouse press event came, always pass it as "mouse held this frame", so we don't miss click-release events that are shorter than 1 frame.
-    io.MouseDown[1] = bd->MousePressed[1] || (mouse_buttons & SDL_BUTTON(SDL_BUTTON_RIGHT)) != 0;
-    io.MouseDown[2] = bd->MousePressed[2] || (mouse_buttons & SDL_BUTTON(SDL_BUTTON_MIDDLE)) != 0;
-    bd->MousePressed[0] = bd->MousePressed[1] = bd->MousePressed[2] = false;
 }
 
 static void ImGui_ImplSDL2_UpdateMouseCursor()

backends/imgui_impl_win32.cpp

@@ -34,6 +34,7 @@ typedef DWORD (WINAPI *PFN_XInputGetState)(DWORD, XINPUT_STATE*);
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2022-01-17: Inputs: calling new io.AddMousePosEvent(), io.AddMouseButtonEvent(), io.AddMouseWheelEvent() API (1.87+).
 //  2022-01-17: Inputs: always calling io.AddKeyModsEvent() 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.
@@ -265,7 +266,7 @@ static void ImGui_ImplWin32_UpdateMouseData()
         {
             POINT pos;
             if (::GetCursorPos(&pos) && ::ScreenToClient(bd->hWnd, &pos))
-                io.MousePos = ImVec2((float)pos.x, (float)pos.y);
+                io.AddMousePosEvent((float)pos.x, (float)pos.y);
         }
     }
 }
@@ -510,13 +511,13 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
             ::TrackMouseEvent(&tme);
             bd->MouseTracked = true;
         }
-        io.MousePos = ImVec2((float)GET_X_LPARAM(lParam), (float)GET_Y_LPARAM(lParam));
+        io.AddMousePosEvent((float)GET_X_LPARAM(lParam), (float)GET_Y_LPARAM(lParam));
         break;
     case WM_MOUSELEAVE:
         if (bd->MouseHwnd == hwnd)
             bd->MouseHwnd = NULL;
         bd->MouseTracked = false;
-        io.MousePos = ImVec2(-FLT_MAX, -FLT_MAX);
+        io.AddMousePosEvent(-FLT_MAX, -FLT_MAX);
         break;
     case WM_LBUTTONDOWN: case WM_LBUTTONDBLCLK:
     case WM_RBUTTONDOWN: case WM_RBUTTONDBLCLK:
@@ -531,7 +532,7 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
         if (bd->MouseButtonsDown == 0 && ::GetCapture() == NULL)
             ::SetCapture(hwnd);
         bd->MouseButtonsDown |= 1 << button;
-        io.MouseDown[button] = true;
+        io.AddMouseButtonEvent(button, true);
         return 0;
     }
     case WM_LBUTTONUP:
@@ -547,14 +548,14 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
         bd->MouseButtonsDown &= ~(1 << button);
         if (bd->MouseButtonsDown == 0 && ::GetCapture() == hwnd)
             ::ReleaseCapture();
-        io.MouseDown[button] = false;
+        io.AddMouseButtonEvent(button, false);
         return 0;
     }
     case WM_MOUSEWHEEL:
-        io.MouseWheel += (float)GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA;
+        io.AddMouseWheelEvent(0.0f, (float)GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA);
         return 0;
     case WM_MOUSEHWHEEL:
-        io.MouseWheelH += (float)GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA;
+        io.AddMouseWheelEvent((float)GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA, 0.0f);
         return 0;
     case WM_KEYDOWN:
     case WM_KEYUP:

docs/CHANGELOG.txt

@@ -38,7 +38,10 @@ HOW TO UPDATE?
 Breaking Changes:
 
 - Removed support for pre-C++11 compilers. We'll stop supporting VS2010. (#4537)
-- Reworked IO keyboard input system. (#2625, #3724) [@thedmd, @ocornut]
+- Reworked IO mouse input API: (#4858) [@thedmd, @ocornut]
+  - Added io.AddMousePosEvent(), AddMouseButtonEvent(), AddMouseWheelEvent() functions,
+    obsoleting writing directly to io.MousePos, io.MouseDown[], io.MouseWheel, etc.
+- Reworked IO keyboard input API: (#2625, #3724) [@thedmd, @ocornut]
   - Added io.AddKeyEvent() function, obsoleting writing directly to io.KeyMap[], io.KeysDown[] arrays.
   - Added io.AddKeyModsEvent() function, obsoleting writing directly to io.KeyCtrl, io.KeyShift etc.
   - Added io.SetKeyEventNativeData() function (optional) to pass native and old legacy indices.
@@ -47,9 +50,10 @@ Breaking Changes:
   - Obsoleted GetKeyIndex(): it is now unnecessary and will now return the same value.
   - All keyboard related functions taking 'int user_key_index' now take 'ImGuiKey key':
     - IsKeyDown(), IsKeyPressed(), IsKeyReleased(), GetKeyPressedAmount().
-  - All backends were updated to use io.AddKeyEvent().
+  - Added io.ConfigInputEventQueue (defaulting to true) to disable input queue trickling.
   - Backward compatibility:
-    - Old backends populating those arrays should still work! (for a while)
+    - All backends updated to use new functions.
+    - Old backends populating those arrays should still work!
     - Calling e.g. IsKeyPressed(MY_NATIVE_KEY_XXX) will still work! (for a while)
     - Those legacy arrays will only be disabled if '#define IMGUI_DISABLE_OBSOLETE_KEYIO' is set in your imconfig.
       In a few versions, IMGUI_DISABLE_OBSOLETE_FUNCTIONS will automatically enable IMGUI_DISABLE_OBSOLETE_KEYIO,
@@ -104,16 +108,21 @@ Other Changes:
   We are now converting GLFW untranslated keycodes back to translated keycodes in order to match the behavior of every
   other backend, and facilitate the use of GLFW with lettered-shortcuts API. (#456, #2625)
 - Backends: GLFW: Submit keys using io.AddKeyEvent(). Submit keymods using io.AddKeyModsEvent() at the same time. (#2625)
+- Backends: GLFW: Submit mouse data using io.AddMousePosEvent(), AddMouseButtonEvent(), AddMouseWheelEvent() functions. (#4858)
 - Backends: GLFW: Update mouse position using glfwSetCursorPosCallback() + fallback when focused but not hovered/captured.
 - Backends: Win32: Submit keys using io.AddKeyEvent(). Submit keymods using io.AddKeyModsEvent() at the same time. (#2625)
 - Backends: Win32: Update mouse position using WM_MOUSEMOVE/WM_MOUSELEAVE + fallback when focused but not hovered/captured.
+- Backends: Win32: Submit mouse data using io.AddMousePosEvent(), AddMouseButtonEvent(), AddMouseWheelEvent() functions. (#4858)
 - Backends: Win32: Maintain a MouseButtonsDown mask instead of using ImGui::IsAnyMouseDown() which will be obsoleted.
 - Backends: SDL: Pass localized keys (matching keyboard layout). Fix e.g. CTRL+A, CTRL+Z, CTRL+Y shortcuts.
 - Backends: SDL: Submit keys using io.AddKeyEvent(). Submit keymods using io.AddKeyModsEvent() at the same time. (#2625)
 - Backends: SDL: Update mouse position using SDL_MOUSEMOTION/SDL_WINDOWEVENT_LEAVE + fallback when focused but not hovered/captured.
+- Backends: SDL: Submit mouse data using io.AddMousePosEvent(), AddMouseButtonEvent(), AddMouseWheelEvent() functions. (#4858)
 - Backends: SDL: Maintain a MouseButtonsDown mask instead of using ImGui::IsAnyMouseDown() which will be obsoleted.
 - Backends: Allegro5: Submit keys using io.AddKeyEvent(). Submit keymods using io.AddKeyModsEvent() at the same time. (#2625)
+- Backends: Allegro5: Submit mouse data using io.AddMousePosEvent(), AddMouseButtonEvent(), AddMouseWheelEvent() functions. (#4858)
 - Backends: Android, GLUT, OSX: Submit keys using io.AddKeyEvent(). Submit keymods using io.AddKeyModsEvent() at the same time. (#2625)
+- Backends: Android, GLUT, OSX: Submit mouse data using io.AddMousePosEvent(), AddMouseButtonEvent(), AddMouseWheelEvent() functions. (#4858)
 - Backends: OpenGL3: Fixed a buffer overflow in imgui_impl_opengl3_loader.h init (added in 1.86). (#4468, #4830) [@dymk]
   It would generally not have noticeable side-effect at runtime but would be detected by runtime checkers.
 - Backends: Metal: Added Apple Metal C++ API support. (#4824, #4746) [@luigifcruz]

imgui.cpp

@@ -1262,7 +1262,7 @@ void ImGuiIO::AddKeyEvent(ImGuiKey key, bool down)
     KeysData[keydata_index].Down = down;
 }
 
-// [Optional] Call add AddKeyEvent().
+// [Optional] Call after AddKeyEvent().
 // Specify native keycode, scancode + Specify index for legacy <1.87 IsKeyXXX() functions with native indices.
 // If you are writing a backend in 2022 or don't use IsKeyXXX() with native values that are not ImGuiKey values, you can avoid calling this.
 void ImGuiIO::SetKeyEventNativeData(ImGuiKey key, int native_keycode, int native_scancode, int native_legacy_index)
@@ -1294,6 +1294,32 @@ void ImGuiIO::AddKeyModsEvent(ImGuiKeyModFlags modifiers)
     KeySuper = (modifiers & ImGuiKeyModFlags_Super) != 0;
 }
 
+// Queue a mouse move event
+void ImGuiIO::AddMousePosEvent(float x, float y)
+{
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(&g.IO == this && "Can only add events to current context.");
+    g.IO.MousePos = ImVec2(x, y);
+}
+
+void ImGuiIO::AddMouseWheelEvent(float wheel_x, float wheel_y)
+{
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(&g.IO == this && "Can only add events to current context.");
+    if (wheel_x == 0.0f && wheel_y == 0.0f)
+        return;
+    g.IO.MouseWheelH += wheel_x;
+    g.IO.MouseWheel += wheel_y;
+}
+
+void ImGuiIO::AddMouseButtonEvent(int mouse_button, bool down)
+{
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(&g.IO == this && "Can only add events to current context.");
+    IM_ASSERT(mouse_button >= 0 && mouse_button < ImGuiMouseButton_COUNT);
+    g.IO.MouseDown[mouse_button] = down;
+}
+
 void ImGuiIO::AddFocusEvent(bool focused)
 {
     // We intentionally overwrite this and process in NewFrame(), in order to give a chance

imgui.h

@@ -65,7 +65,7 @@ Index of this file:
 // Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals. Work in progress versions typically starts at XYY99 then bounce up to XYY00, XYY01 etc. when release tagging happens)
 #define IMGUI_VERSION               "1.87 WIP"
-#define IMGUI_VERSION_NUM           18606
+#define IMGUI_VERSION_NUM           18607
 #define IMGUI_CHECKVERSION()        ImGui::DebugCheckVersionAndDataLayout(IMGUI_VERSION, sizeof(ImGuiIO), sizeof(ImGuiStyle), sizeof(ImVec2), sizeof(ImVec4), sizeof(ImDrawVert), sizeof(ImDrawIdx))
 #define IMGUI_HAS_TABLE
 
@@ -1994,10 +1994,14 @@ struct ImGuiIO
     // Input Functions
     IMGUI_API void  AddKeyEvent(ImGuiKey key, bool down);       // Queue a new key down/up event. Key should be "translated" (as in, generally ImGuiKey_A matches the key end-user would use to emit an 'A' character)
     IMGUI_API void  AddKeyModsEvent(ImGuiKeyModFlags modifiers);// Queue a change of Ctrl/Shift/Alt/Super modifiers
+    IMGUI_API void  AddMousePosEvent(float x, float y);         // Queue a mouse position update. Use -FLT_MAX,-FLT_MAX to signify no mouse (e.g. app not focused and not hovered)
+    IMGUI_API void  AddMouseButtonEvent(int button, bool down); // Queue a mouse button change
+    IMGUI_API void  AddMouseWheelEvent(float wh_x, float wh_y); // Queue a mouse wheel update
     IMGUI_API void  AddFocusEvent(bool focused);                // Queue an hosting application/platform windows gain or loss of focus
     IMGUI_API void  AddInputCharacter(unsigned int c);          // Queue new character input
     IMGUI_API void  AddInputCharacterUTF16(ImWchar16 c);        // Queue new character input from an UTF-16 character, it can be a surrogate
     IMGUI_API void  AddInputCharactersUTF8(const char* str);    // Queue new characters input from an UTF-8 string
+
     IMGUI_API void  ClearInputCharacters();                     // [Internal] Clear the text input buffer manually
     IMGUI_API void  ClearInputKeys();                           // [Internal] Release all keys
     IMGUI_API void  SetKeyEventNativeData(ImGuiKey key, int native_keycode, int native_scancode, int native_legacy_index = -1); // [Optional] Specify index for legacy <1.87 IsKeyXXX() functions with native indices + specify native keycode, scancode.