Fixed SDL(3)_SetRenderScale handling

Fixed ocornut#6065

backends/imgui_impl_sdl3.cpp

@@ -264,6 +264,11 @@ bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
         {
             ImVec2 mouse_pos((float)event->motion.x, (float)event->motion.y);
             io.AddMouseSourceEvent(event->motion.which == SDL_TOUCH_MOUSEID ? ImGuiMouseSource_TouchScreen : ImGuiMouseSource_Mouse);
+            float rsx = 1.0f;
+            float rsy = 1.0f;
+            SDL_GetRenderScale(bd->Renderer, &rsx, &rsy);
+            mouse_pos.x /= rsx;
+            mouse_pos.y /= rsy;
             io.AddMousePosEvent(mouse_pos.x, mouse_pos.y);
             return true;
         }
@@ -276,6 +281,11 @@ bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
             wheel_x /= 100.0f;
     #endif
             io.AddMouseSourceEvent(event->wheel.which == SDL_TOUCH_MOUSEID ? ImGuiMouseSource_TouchScreen : ImGuiMouseSource_Mouse);
+            float rsx = 1.0f;
+            float rsy = 1.0f;
+            SDL_GetRenderScale(bd->Renderer, &rsx, &rsy);
+            wheel_x /= rsx;
+            wheel_y /= rsy;
             io.AddMouseWheelEvent(wheel_x, wheel_y);
             return true;
         }
@@ -492,7 +502,14 @@ static void ImGui_ImplSDL3_UpdateMouseData()
             int window_x, window_y;
             SDL_GetGlobalMouseState(&mouse_x_global, &mouse_y_global);
             SDL_GetWindowPosition(focused_window, &window_x, &window_y);
-            io.AddMousePosEvent(mouse_x_global - window_x, mouse_y_global - window_y);
+            mouse_x_global -= window_x;
+            mouse_y_global -= window_y;
+            float rsx = 1.0f;
+            float rsy = 1.0f;
+            SDL_GetRenderScale(bd->Renderer, &rsx, &rsy);
+            mouse_x_global /= rsx;
+            mouse_y_global /= rsy;
+            io.AddMousePosEvent(mouse_x_global, mouse_y_global);
         }
     }
 }