Innovation for
performance

#include <windows.h>

LRESULT CALLBACK WindowProc(HWND window,
    UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message) {
    case WM_CREATE:
        return 0;
    case WM_PAINT: {
        PAINTSTRUCT paint;
        HDC dc = BeginPaint(window, &paint);
        const char text[] = "Ready";
        TextOutA(dc, 16, 16, text, sizeof(text)-1);
        EndPaint(window, &paint);
        return 0;
    }
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(window, message,
                         wParam, lParam);
}

int WINAPI WinMain(HINSTANCE instance,
    HINSTANCE previous, LPSTR command, int show)
{
    WNDCLASSA cls = {0};
    cls.lpfnWndProc = WindowProc;
    cls.hInstance = instance;
    cls.lpszClassName = "MainWindow";
    RegisterClassA(&cls);
    HWND window = CreateWindowA("MainWindow",
        "Desktop", WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT, 640, 480,
        NULL, NULL, instance, NULL);
    ShowWindow(window, show);
    MSG message;
    while (GetMessage(&message, NULL, 0, 0) > 0) {
        TranslateMessage(&message);
        DispatchMessage(&message);
    }
    return (int)message.wParam;
}