gdk_draw_pixmap() copies a
region from a pixmap to another drawable (pixmap or
window). The source and destination drawables must have
the same depth and visual. If you pass -1 for the width or height, the full
size of the source pixmap is substituted. The source can
actually be any drawable, including a window, but gdk_window_copy_area() will make
your code clearer if the source is a window. Figure 23 shows gdk_draw_pixmap().
