Copies the width x height region of src at coordinates (xsrc, ysrc) to coordinates (xdest, ydest) in drawable. width and/or height may be given as -1, in which case the entire src drawable will be copied. Most fields in gc are not used for this operation, but notably the clip mask or clip region will be honored.The source and destination drawables must have the same visual and colormap, or errors will result. (On X11, failure to match visual/colormap results in a BadMatch error from the X server.) A common cause of this problem is an attempt to draw a bitmap to a color drawable. The way to draw a bitmap is to set the bitmap as a clip mask on your #GdkGC, then use Drawable.DrawRectangle to draw a rectangle clipped to the bitmap.