//
// gcc xwin-gl-probe.c -lgdi32 -lopengl32 -o xwin-gl-probe.exe -Wall
//

#include <stdio.h>
#include <windows.h>

int
main(void)
{
    HWND hwnd;
    HDC hdc;
    HGLRC hglrc;

    // create window class
#define WIN_GL_TEST_WINDOW_CLASS L"XWinGLTest"
    {
        static ATOM glTestWndClass = 0;

        if (glTestWndClass == 0) {
            WNDCLASSEXW wc;

            wc.cbSize = sizeof(WNDCLASSEX);
            wc.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
            wc.lpfnWndProc = DefWindowProc;
            wc.cbClsExtra = 0;
            wc.cbWndExtra = 0;
            wc.hInstance = GetModuleHandle(NULL);
            wc.hIcon = 0;
            wc.hCursor = 0;
            wc.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH);
            wc.lpszMenuName = NULL;
            wc.lpszClassName = WIN_GL_TEST_WINDOW_CLASS;
            wc.hIconSm = 0;
            RegisterClassExW(&wc);
        }
    }

   // create an invisible window for a scratch DC
   hwnd = CreateWindowExW(0,
                           WIN_GL_TEST_WINDOW_CLASS,
                           L"XWin GL Renderer Capabilities Test Window",
                           WS_OVERLAPPEDWINDOW|WS_VISIBLE, 0, 0, 0, 0, NULL, NULL, GetModuleHandle(NULL),
                           NULL);
    if (hwnd == NULL) {
        printf("Couldn't create a window for render capabilities testing\n");
        goto error;
    }

    hdc = GetDC(hwnd);
    if (!hdc) {
        printf("Couldn't create a DC for render capabilities testing\n");
        goto error;
    }

    // we must set a pixel format before we can create a context
    {
        PIXELFORMATDESCRIPTOR pfd = {
            sizeof(PIXELFORMATDESCRIPTOR),
            1,
            PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DEPTH_DONTCARE | PFD_DOUBLEBUFFER_DONTCARE | PFD_STEREO_DONTCARE,
            PFD_TYPE_RGBA,
            24,
            0, 0, 0, 0, 0, 0,
            0,
            0,
            0,
            0, 0, 0, 0,
            0,
            0,
            0,
            PFD_MAIN_PLANE,
            0,
            0, 0, 0
        };

        int iPixelFormat = ChoosePixelFormat(hdc, &pfd);
        if (iPixelFormat == 0) {
            printf("ChoosePixelFormat failed\n");
            goto error;
        }

        if (!SetPixelFormat(hdc, iPixelFormat, NULL)) {
            printf("SetPixelFormat %d failed\n", iPixelFormat);
            goto error;
        }
        printf("Testing pixelFormatIndex %d\n",iPixelFormat);
    }

    hglrc = wglCreateContext(hdc);
    if (!wglMakeCurrent(hdc, hglrc)) {
        printf("wglMakeCurrent error: %08x dc %p ctx %p\n", (unsigned)GetLastError(), hdc, hglrc);
    }

    printf("Done\n");
error:
    return 0;
}