OpenGL: Fix screenshot gray edge issue by correcting SetWindowPos usage

- OpenGLSwapChain::Initialize now uses AdjustWindowRect before SetWindowPos
- This ensures window client area matches expected size (1280x720)
- Previously SetWindowPos was given client area size instead of full window size
- Removed debug fprintf statements from OpenGLDevice
- Updated minimal integration test to use cleaner code

engine/src/RHI/OpenGL/OpenGLDevice.cpp

@@ -1,7 +1,6 @@
 #define WIN32_LEAN_AND_MEAN
 #define NOMINMAX
 
-#include <stdio.h>
 #include <glad/glad.h>
 #include <windows.h>
 
@@ -104,17 +103,14 @@ bool OpenGLDevice::InitializeWithExistingWindow(HWND hwnd) {
     }
 
     if (!hwnd) {
-        fprintf(stderr, "[OpenGLDevice] ERROR: hwnd is null\n");
         return false;
     }
 
     m_hwnd = hwnd;
     m_hdc = ::GetDC(m_hwnd);
     if (!m_hdc) {
-        fprintf(stderr, "[OpenGLDevice] ERROR: GetDC failed\n");
         return false;
     }
-    fprintf(stderr, "[OpenGLDevice] GetDC succeeded\n");
 
     PIXELFORMATDESCRIPTOR pfd = {};
     pfd.nSize = sizeof(PIXELFORMATDESCRIPTOR);
@@ -128,42 +124,33 @@ bool OpenGLDevice::InitializeWithExistingWindow(HWND hwnd) {
 
     int pixelFormat = ChoosePixelFormat(m_hdc, &pfd);
     if (!pixelFormat) {
-        fprintf(stderr, "[OpenGLDevice] ERROR: ChoosePixelFormat failed\n");
         ReleaseDC(m_hwnd, m_hdc);
         m_hdc = nullptr;
         return false;
     }
-    fprintf(stderr, "[OpenGLDevice] ChoosePixelFormat succeeded\n");
 
     if (!SetPixelFormat(m_hdc, pixelFormat, &pfd)) {
-        fprintf(stderr, "[OpenGLDevice] ERROR: SetPixelFormat failed\n");
         ReleaseDC(m_hwnd, m_hdc);
         m_hdc = nullptr;
         return false;
     }
-    fprintf(stderr, "[OpenGLDevice] SetPixelFormat succeeded\n");
 
     m_hglrc = wglCreateContext(m_hdc);
     if (!m_hglrc) {
-        fprintf(stderr, "[OpenGLDevice] ERROR: wglCreateContext failed\n");
         ReleaseDC(m_hwnd, m_hdc);
         m_hdc = nullptr;
         return false;
     }
-    fprintf(stderr, "[OpenGLDevice] wglCreateContext succeeded\n");
 
     if (!wglMakeCurrent(m_hdc, m_hglrc)) {
-        fprintf(stderr, "[OpenGLDevice] ERROR: wglMakeCurrent failed\n");
         wglDeleteContext(m_hglrc);
         ReleaseDC(m_hwnd, m_hdc);
         m_hglrc = nullptr;
         m_hdc = nullptr;
         return false;
     }
-    fprintf(stderr, "[OpenGLDevice] wglMakeCurrent succeeded\n");
 
     if (!gladLoadGL()) {
-        fprintf(stderr, "[OpenGLDevice] ERROR: gladLoadGL failed\n");
         wglMakeCurrent(nullptr, nullptr);
         wglDeleteContext(m_hglrc);
         ReleaseDC(m_hwnd, m_hdc);
@@ -171,7 +158,6 @@ bool OpenGLDevice::InitializeWithExistingWindow(HWND hwnd) {
         m_hdc = nullptr;
         return false;
     }
-    fprintf(stderr, "[OpenGLDevice] gladLoadGL succeeded\n");
 
     const char* vendor = reinterpret_cast<const char*>(glGetString(GL_VENDOR));
     const char* renderer = reinterpret_cast<const char*>(glGetString(GL_RENDERER));

engine/src/RHI/OpenGL/OpenGLSwapChain.cpp

@@ -68,7 +68,9 @@ bool OpenGLSwapChain::Initialize(HWND window, int width, int height, PresentMode
         wglSwapIntervalEXT(m_vsync ? 1 : 0);
     }
 
-    ::SetWindowPos(m_hwnd, nullptr, 0, 0, width, height, SWP_NOMOVE | SWP_NOZORDER);
+    RECT rect = { 0, 0, width, height };
+    ::AdjustWindowRect(&rect, WS_OVERLAPPEDWINDOW, FALSE);
+    ::SetWindowPos(m_hwnd, nullptr, 0, 0, rect.right - rect.left, rect.bottom - rect.top, SWP_NOMOVE | SWP_NOZORDER);
 
     m_framebufferWidth = width;
     m_framebufferHeight = height;
@@ -135,7 +137,9 @@ void OpenGLSwapChain::Resize(uint32_t width, uint32_t height) {
     m_width = width;
     m_height = height;
     if (m_hwnd) {
-        ::SetWindowPos(m_hwnd, nullptr, 0, 0, width, height, SWP_NOMOVE | SWP_NOZORDER);
+    RECT rect = { 0, 0, width, height };
+    ::AdjustWindowRect(&rect, WS_OVERLAPPEDWINDOW, FALSE);
+    ::SetWindowPos(m_hwnd, nullptr, 0, 0, rect.right - rect.left, rect.bottom - rect.top, SWP_NOMOVE | SWP_NOZORDER);
     }
     m_framebufferWidth = width;
     m_framebufferHeight = height;

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

@@ -1,5 +1,7 @@
 #include <stdio.h>
 #include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
 
 #include <glad/glad.h>
 #include <windows.h>
@@ -35,7 +37,12 @@ void SaveScreenshotPPM(const char* filename, int width, int height) {
         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");
@@ -101,23 +108,16 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine
         NULL, NULL, hInstance, NULL
     );
 
-    RECT clientRect;
-    GetClientRect(hwnd, &clientRect);
-    fprintf(stderr, "[minimal] Window client area: %ldx%ld\n", clientRect.right, clientRect.bottom);
-
     if (!hwnd) {
         Log("[ERROR] Failed to create window");
         return -1;
     }
 
     OpenGLDevice device;
-    fprintf(stderr, "[minimal] About to call InitializeWithExistingWindow\n");
     if (!device.InitializeWithExistingWindow(hwnd)) {
-        fprintf(stderr, "[minimal] InitializeWithExistingWindow returned false\n");
         Log("[ERROR] Failed to initialize OpenGL device");
         return -1;
     }
-    fprintf(stderr, "[minimal] InitializeWithExistingWindow succeeded\n");
 
     ShowWindow(hwnd, nShowCmd);
     UpdateWindow(hwnd);
@@ -132,7 +132,7 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine
     int frameCount = 0;
     const int targetFrameCount = 30;
 
-    while (true) {
+    while (frameCount < targetFrameCount) {
         if (PeekMessageW(&msg, NULL, 0, 0, PM_REMOVE)) {
             if (msg.message == WM_QUIT) {
                 break;
@@ -145,15 +145,12 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine
             glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
             swapChain.Present(0, 0);
             frameCount++;
-
-            if (frameCount >= targetFrameCount) {
-                Log("[INFO] Reached target frame count %d - taking screenshot!", targetFrameCount);
-                SaveScreenshotPPM("minimal.ppm", gWidth, gHeight);
-                break;
-            }
         }
     }
 
+    Log("[INFO] Reached target frame count %d - taking screenshot!", targetFrameCount);
+    SaveScreenshotPPM("minimal.ppm", gWidth, gHeight);
+
     swapChain.Shutdown();
     device.Shutdown();
     Logger::Get().Shutdown();