XEmptyRegion 3X11 __xorgversion__ XLIB FUNCTIONS XEmptyRegion XEqualRegion XPointInRegion XRectInRegion determine if regions are empty or equal Bool XEmptyRegion ( Region r ); Bool XEqualRegion ( Region r1 , Region r2 ); Bool XPointInRegion ( Region r , int x , int y ); int XRectInRegion ( Region r , int x , int y , unsigned int width , unsigned int height ); r Specifies the region. r1 r2 Specify the two regions. width height Specify the width and height, which define the rectangle. or the coordinates of the upper-left corner of the rectangle x y Specify the x and y coordinates, which define the point. The  XEmptyRegion  function returns  True  if the region is empty. The  XEqualRegion  function returns  True  if the two regions have the same offset, size, and shape. The  XPointInRegion  function returns  True  if the point (x, y) is contained in the region r. The  XRectInRegion  function returns  RectangleIn  if the rectangle is entirely in the specified region,  RectangleOut  if the rectangle is entirely out of the specified region, and  RectanglePart  if the rectangle is partially in the specified region. XCreateRegion(3X11), XIntersectRegion(3X11) Xlib - C Language X Interface