VCopyImageWindowArea - copies an area of the image window or its subwindows.
VCopyImageWindowArea(win, x_src, y_src, width, height, x_dst, y_dst)
int x_src, y_src;
int width, height;
int x_dst, y_dst;
VCopyImageWindowArea copies an area of the image window or one of its
subwindows to a new region in the same window. This can be used to scroll
parts of a window.
0 - work successfully.
6 - invalid window ID.
win - window ID.
x_src - x coordinate of top left point of the source region.
y_src - y coordinate of top left point of the source region.
width,height- width and height of region.
x_dst - x coordinate of top left point of the destination region.
y_dst - y coordinate of top left point of the destination region.
Copying region would destroy what is under the destination window.
The win should be the image window or one of its subwindows. Copying
region should be within the specified window. Destination region should be
at least partially within the window.