Find the control surface hit by a given point
PtSurface_t *PtSurfaceHit( PtWidget_t *widget, PhPoint_t const *point, unsigned long event_mask, PtSurface_t const *surface );
PtSurfaceHit() finds the control surface, belonging to the given widget, at the coordinates pointed to by point.
The event_mask specifies the event types to which the control surface must be sensitive. A value of 0 means any event types.
The surface argument, if not NULL is the control surface to test first.
A pointer to the control surface hit by the given point, or NULL if there isn't one or an error occurred.
PhPoint_t, PtSurfaceCalcBoundingBox(), PtSurfaceRect(), PtSurfaceTestPoint()
Control Surfaces chapter of the Photon Programmer's Guide