linux.py 文件源码

def get_pixels_slow(self, ximage):
        ''' Retrieve all pixels from a monitor. Pixels have to be RGB.
            (!) Insanely slow version, see doc/linux-slow-version. (!)
        '''

        # @TODO: this part takes most of the time. Need a better solution.
        def pix(pixel, _resultats={}, p__=pack):
            ''' Apply shifts to a pixel to get the RGB values.
                This method uses of memoization.
            '''

            # pylint: disable=dangerous-default-value

            if pixel not in _resultats:
                _resultats[pixel] = p__('<B', (pixel & rmask) >> 16) + \
                    p__('<B', (pixel & gmask) >> 8) + \
                    p__('<B', pixel & bmask)
            return _resultats[pixel]

        self.width = ximage.contents.width
        self.height = ximage.contents.height
        rmask = ximage.contents.red_mask
        bmask = ximage.contents.blue_mask
        gmask = ximage.contents.green_mask
        get_pix = self.xlib.XGetPixel
        pixels = [pix(get_pix(ximage, x, y))
                  for y in range(self.height) for x in range(self.width)]
        self.image = b''.join(pixels)
        return self.image