Win32 Game Loop

main.c

#include <Windows.h>
#include <tchar.h>

#define CURRENT_WND_CLASS _T("GameWndClass_Didiet")
#define DEF_CX 800
#define DEF_CY 600

LRESULT CALLBACK WndProc( HWND, UINT, WPARAM, LPARAM );

INT WINAPI _tWinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow )
{
	WNDCLASSEX wcex; /* Structure needed for creating Window */
	HWND hWnd;       /* Window Handle */
	MSG msg;
	BOOL bDone = FALSE;
	SIZE screenSize;
	LONG winX, winY;

	ZeroMemory(&wcex, sizeof(WNDCLASSEX));
	ZeroMemory(&msg, sizeof(MSG));

	wcex.cbSize = sizeof(WNDCLASSEX);
	wcex.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH);
	wcex.hCursor = LoadCursor(hInstance, IDC_ARROW);
	wcex.hIcon   = LoadIcon(hInstance, IDI_APPLICATION);
	wcex.hInstance = hInstance;
	wcex.lpfnWndProc = WndProc;
	wcex.lpszClassName = CURRENT_WND_CLASS;
	wcex.style = CS_HREDRAW | CS_VREDRAW;
	wcex.cbWndExtra = 0;
	wcex.cbClsExtra = 0;
	wcex.lpszMenuName = NULL;

	if (!RegisterClassEx(&wcex)) {
		return -1;
	}

	screenSize.cx = GetSystemMetrics(SM_CXSCREEN);
	screenSize.cy = GetSystemMetrics(SM_CYSCREEN);

	winX = ( screenSize.cx - (DEF_CX + GetSystemMetrics(SM_CXBORDER)*2) ) / 2;
	winY = ( screenSize.cy - (DEF_CY + GetSystemMetrics(SM_CYBORDER) + GetSystemMetrics(SM_CYCAPTION)) ) / 2;

	hWnd = CreateWindowEx(
		WS_EX_OVERLAPPEDWINDOW,
		CURRENT_WND_CLASS,
		_T("Game Window"),
		WS_OVERLAPPEDWINDOW,
		winX,winY,
		DEF_CX,DEF_CY,
		0,
		0,
		hInstance,
		0);

	ShowWindow(hWnd, SW_SHOW);
	UpdateWindow(hWnd);

	while (FALSE == bDone) {
		if (PeekMessage(&msg, hWnd, 0, 0, PM_REMOVE)) {
			TranslateMessage(&msg);
			DispatchMessage(&msg);

			if (msg.message == WM_QUIT) {
				bDone = TRUE;
			}
		}
		else {
			/* do rendering here */
		}
	}

	DestroyWindow( hWnd );
	UnregisterClass(CURRENT_WND_CLASS, hInstance);
	return 0;
}

LRESULT CALLBACK WndProc( HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam )
{
	switch( uMsg )
	{
	case WM_QUIT:
	case WM_DESTROY:
	case WM_CLOSE:
		PostQuitMessage(0);
		break;
	default:
		return DefWindowProc(hWnd, uMsg, wParam, lParam);
	}
	return 0;
}

Thanks 👍

Very useful for the non-blocking part, thank you!