/* vidfmt.c:  Check video display format */

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

int main(int argc, char* argv[])
{
    int dib_size;
    LPBITMAPINFOHEADER dib_hdr;
    HDC hdc;
    HBITMAP hbm;

    /* Allocate enough space for a DIB header plus palette (for
     * 8-bit modes) or bitfields (for 16- and 32-bit modes)
     */
    dib_size = sizeof(BITMAPINFOHEADER) + 256 * sizeof (RGBQUAD);
    dib_hdr = (LPBITMAPINFOHEADER) malloc(dib_size);
    memset(dib_hdr, 0, dib_size);
    dib_hdr->biSize = sizeof(BITMAPINFOHEADER);
    
    /* Get a device-dependent bitmap that's compatible with the
       screen.
     */
    hdc = GetDC(NULL);
    hbm = CreateCompatibleBitmap( hdc, 1, 1 );

    /* Convert the DDB to a DIB.  We need to call GetDIBits twice:  
     * the first call just fills in the BITMAPINFOHEADER; the 
     * second fills in the bitfields or palette.
     */
    GetDIBits(hdc, hbm, 0, 1, NULL, (LPBITMAPINFO) dib_hdr, 
        DIB_RGB_COLORS);
    GetDIBits(hdc, hbm, 0, 1, NULL, (LPBITMAPINFO) dib_hdr, 
        DIB_RGB_COLORS);
    DeleteObject(hbm);
    ReleaseDC(NULL, hdc);

    printf("Current video mode is %lu-bit.\n", 
        dib_hdr->biBitCount);

    if (BI_BITFIELDS == dib_hdr->biCompression)
    {
        DWORD * fields = (DWORD*) ((char*)dib_hdr + 
            dib_hdr->biSize);
        switch (fields[0])
        {
        case 0xf800:
            printf("    (565 BGR pixel alignment)\n");
            break;
        case 0x7c00:
            printf("    (555 BGR pixel alignment)\n");
            break;
        case 0xff0000:
            printf("    (888 BGR pixel alignment)\n");
            break;
        case 0x0000ff:
            printf("    (888 RGB pixel alignment)\n");
            break;
        default:
            printf("    (Unknown pixel alignment %x:%x:%x)\n", 
                fields[0], fields[1], fields[2] );
        }
    }

    free(dib_hdr);
    return 0;
}