c/c++ assign RGBQUAD array to a bitmap

问题

i am doing a program where you take a screenshot of a window and then scan every pixel of that picture. But I have a problem assigning RGBQUAD array to the taken screen. Every pixel has the same RGB which is 205. Here is a piece of my code:

RGBQUAD *pixel = malloc((ssWidth * ssHeight)* sizeof(RGBQUAD));
hdcScreen = GetDC(gameHandle);
hdc = CreateCompatibleDC(hdcScreen);
hBmp = CreateCompatibleBitmap(hdcScreen, ssWidth, ssHeight);
SelectObject(hdc, hBmp);

BitBlt(hdc, 0, 0, ssWidth, ssHeight, hdcScreen, xCenter, yCenter, SRCCOPY);

GetDIBits(hdc, hBmp, 0, ssHeight, pixel, &bmpInfo, DIB_RGB_COLORS);

int p = -1;

for(y_var = 0; y_var < ssWidth; y_var++)
{
    for(x_var = 0; x_var < ssHeight; x_var++)
    {
        if(ComparePixel(&pixel[++p]))
        {
            SetCursorPos(xCenter + x_var + 3, yCenter + y_var + 3);
        }
    }
}

bool ComparePixel(RGBQUAD *pixel)
{
    printf("%d, %d, %d\n"; pixel -> rgbRed, pixel -> rgbGreen, pixel -> rgbBlue);
    return false;
}

ComparePixel(RGBQUAD *pixel) function just checks the RGB values. How do i assign the RGBQUAD to the bitmap of the screenshot?

回答1:

Multiple issues.

The RGBQUAD **pixel = malloc(... and free(*pixel) appear to be the problem. I think you want RGBQUAD *pixel = malloc((ssWidth * ssHeight)* sizeof(RGBQUAD)); (only 1 *)
Suspect the pixels in GetDIBits() s/b pixel.
I think you want y_var = 0; (x_var = 0; also)
ComparePixel() is not defined, but I think you want something closer to if(ComparePixel(pixel[x_var+(y_var*ssWidth)], the_pixel_to_compare_against))
The free(*pixel); s/b _after the 2 for loops and should be free(pixel);

来源：https://stackoverflow.com/questions/17271944/c-c-assign-rgbquad-array-to-a-bitmap

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