hpux man page for xpointinregion

XPointInRegion()														  XPointInRegion()

Name
  XPointInRegion - determine if a point is inside a region.

Synopsis
  Bool XPointInRegion(r, x, y)
	Region r;
	int x, y;

Arguments
  r	    Specifies the region.

  x	    Specify the x and y coordinates of the point relative to the region's origin.
  y

Returns
  True if the point is inside the region, else False.

Description
  XPointInRegion() returns True if the point x, y  is contained in the region r.  A point exactly on the boundary of the region is considered
  inside the region.

  Regions are located using an offset from a point (the region origin) which is common to all regions.	It is up to the application to inter-
  pret the location of the region relative to a drawable.

  For more information on regions, see Volume One, Chapter 6, Drawing Graphics and Text.

Structures
  Region is a pointer to an opaque structure type.

See Also
  XClipBox(),  XCreateRegion(),  XDestroyRegion(),  XEmptyRegion(),  XEqualRegion(),  XIntersectRegion(),  XOffsetRegion(), XPolygonRegion(),
  XRectInRegion(), XSetRegion(), XShrinkRegion(), XSubtractRegion(), XUnionRectWithRegion(), XUnionRegion(), XXorRegion().

Xlib - Regions															  XPointInRegion()