public void read_pixels (int x, int y, int width, int height, ReadPixelsFlags source, PixelFormat format, uint8 pixels)
This reads a rectangle of pixels from the current framebuffer where position (0, 0) is the top left.
The pixel at (x, y) is the first read, and the data is returned with a rowstride of (width * 4).
Currently Cogl assumes that the framebuffer is in a premultiplied format so if
format is non-premultiplied it will convert it. To
read the pixel values without any conversion you should either specify a format that doesn't use an alpha channel or use one of the formats
ending in PRE.
The window x position to start reading from
The window y position to start reading from
The width of the rectangle you want to read
The height of the rectangle you want to read
Identifies which auxillary buffer you want to read (only COGL_READ_PIXELS_COLOR_BUFFER supported currently)
The pixel format you want the result in (only COGL_PIXEL_FORMAT_RGBA_8888 supported currently)
The location to write the pixel data.