perf stuff

ImguiBase/ImguiBase.cpp

@@ -448,6 +448,12 @@ int startImgui(ImGuiCallbacks& callbacks, const char* title, int windowWidth, in
         ImGui_ImplVulkan_DestroyFontUploadObjects();
     }
 
+    PerfTimer setupTimer{};
+    PerfTimer drawTimer{};
+    PerfTimer renderTimer{};
+    PerfTimer displayTimer{};
+    int drawCounter = IMGUI_REDRAW_COUNT;
+
     // Main loop
     while (!glfwWindowShouldClose(window))
     {
@@ -456,7 +462,18 @@ int startImgui(ImGuiCallbacks& callbacks, const char* title, int windowWidth, in
         // - 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.
-        glfwPollEvents();
+        if (false && drawCounter == 0)
+        {
+            glfwWaitEvents();
+            drawCounter = IMGUI_REDRAW_COUNT;
+        }
+        else
+        {
+            glfwPollEvents();
+            drawCounter--;
+        }
+
+        setupTimer.Start();
 
         // Resize swap chain?
         if (g_SwapChainRebuild)
@@ -480,6 +497,9 @@ int startImgui(ImGuiCallbacks& callbacks, const char* title, int windowWidth, in
         ImVec2 prevWindowSize = getWindowSize(window);
         drawData.window_size = prevWindowSize;
 
+        setupTimer.End();
+        drawTimer.Start();
+
         if (callbacks.drawFunc)
         {
             callbacks.drawFunc(drawData);
@@ -490,8 +510,12 @@ int startImgui(ImGuiCallbacks& callbacks, const char* title, int windowWidth, in
             glfwSetWindowSize(window, drawData.window_size.x, drawData.window_size.y);
         }
 
+        drawTimer.End();
+        renderTimer.Start();
+
         // Rendering
         ImGui::Render();
+
         ImDrawData* draw_data = ImGui::GetDrawData();
         const bool is_minimized = (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f);
         if (!is_minimized)
@@ -501,8 +525,21 @@ int startImgui(ImGuiCallbacks& callbacks, const char* title, int windowWidth, in
             wd->ClearValue.color.float32[2] = drawData.clear_color.z * drawData.clear_color.w;
             wd->ClearValue.color.float32[3] = drawData.clear_color.w;
             FrameRender(wd, draw_data);
+            renderTimer.End();
+
+            displayTimer.Start();
             FramePresent(wd);
+            displayTimer.End();
         }
+        else
+        {
+            renderTimer.End();
+        }
+
+        drawData.frameTimeSetup = setupTimer.resultSeconds;
+        drawData.frameTimeDraw = drawTimer.resultSeconds;
+        drawData.frameTimeRender = renderTimer.resultSeconds;
+        drawData.frameTimeDisplay = displayTimer.resultSeconds;
     }
 
     // Cleanup

ImguiBase/ImguiBase.h

@@ -11,12 +11,18 @@
 #include "imgui.h"
 #include "remixicon.h"
 
+#define IMGUI_REDRAW_COUNT 3
+
 class DrawData {
 public:
     GLFWwindow* window = nullptr;
     HWND window_handle = nullptr;
     ImVec4 clear_color = {};
     ImVec2 window_size = {};
+    float frameTimeSetup = 0.f;
+    float frameTimeDraw = 0.f;
+    float frameTimeRender = 0.f;
+    float frameTimeDisplay = 0.f;
 };
 
 class ImGuiCallbacks {
@@ -26,6 +32,28 @@ public:
     std::function<void(DrawData&)> cleanupFunc = nullptr;
 };
 
+class PerfTimer {
+private:
+    LARGE_INTEGER start;
+    LARGE_INTEGER end;
+    LARGE_INTEGER freq;
+
+public:
+    LONGLONG resultTicks;
+    float resultSeconds;
+
+public:
+    void Start() {
+        QueryPerformanceFrequency(&freq);
+        QueryPerformanceCounter(&start);
+    }
+    void End() {
+        QueryPerformanceCounter(&end);
+        resultTicks = end.QuadPart - start.QuadPart;
+        resultSeconds = static_cast<float>(resultTicks * 1000) / freq.QuadPart;
+    }
+};
+
 int startImgui(ImGuiCallbacks& callbacks, const char* title, int windowWidth, int windowHeight);
 
 ImVec2 getWindowSize(GLFWwindow* window);