Remove kissfft third party library and update OpenGL screenshot

tests/RHI/OpenGL/integration/minimal/main.cpp

@@ -3,12 +3,12 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include <glad/glad.h>
 #include <windows.h>
 
 #include "XCEngine/RHI/OpenGL/OpenGLDevice.h"
 #include "XCEngine/RHI/OpenGL/OpenGLSwapChain.h"
 #include "XCEngine/RHI/OpenGL/OpenGLCommandList.h"
+#include "XCEngine/RHI/OpenGL/OpenGLScreenshot.h"
 #include "XCEngine/Debug/Logger.h"
 #include "XCEngine/Debug/ConsoleLogSink.h"
 #include "XCEngine/Containers/String.h"
@@ -31,43 +31,6 @@ void Log(const char* format, ...) {
     Logger::Get().Debug(LogCategory::Rendering, String(buffer));
 }
 
-void SaveScreenshotPPM(const char* filename, int width, int height) {
-    unsigned char* pixels = (unsigned char*)malloc(width * height * 3);
-    if (!pixels) {
-        Log("[ERROR] Failed to allocate pixel buffer");
-        return;
-    }
-
-    glFinish();
-    glReadBuffer(GL_BACK);
-    glPixelStorei(GL_PACK_ALIGNMENT, 1);
-    glPixelStorei(GL_PACK_ROW_LENGTH, 0);
-    glPixelStorei(GL_PACK_SKIP_PIXELS, 0);
-    glPixelStorei(GL_PACK_SKIP_ROWS, 0);
-    glReadPixels(0, 0, width, height, GL_RGB, GL_UNSIGNED_BYTE, pixels);
-
-    FILE* f = fopen(filename, "wb");
-    if (!f) {
-        Log("[ERROR] Failed to open file for screenshot: %s", filename);
-        free(pixels);
-        return;
-    }
-
-    fprintf(f, "P6\n%d %d\n255\n", width, height);
-
-    unsigned char* row = (unsigned char*)malloc(width * 3);
-    for (int y = height - 1; y >= 0; y--) {
-        memcpy(row, pixels + y * width * 3, width * 3);
-        fwrite(row, 1, width * 3, f);
-    }
-
-    free(row);
-    free(pixels);
-    fclose(f);
-
-    Log("[INFO] Screenshot saved to %s", filename);
-}
-
 LRESULT CALLBACK WindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) {
     switch (msg) {
     case WM_CLOSE:
@@ -163,9 +126,8 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine
     }
 
     // Take screenshot after target frame count is reached
-    // glFinish ensures all OpenGL commands are completed before reading pixels
     Log("[INFO] Reached target frame count %d - taking screenshot!", targetFrameCount);
-    SaveScreenshotPPM("minimal.ppm", gWidth, gHeight);
+    OpenGLScreenshot::Capture(device, swapChain, "minimal.ppm");
 
     // Shutdown in reverse order of initialization
     swapChain.Shutdown();