Locating a Point with Respect to a Region

To determine whether the mouse pointer lies within a region:

• Retrieve the mouse-pointer coordinates and store them in a POINTL structure.

• Call GpiPtInRegion, passing it a handle that identifies the appropriate region and the address of the POINTL structure from Step 1.

• Examine the value that GpiPtInRegion returns to determine whether the point lies within the region.

The following figure shows how to locate the mouse pointer with respect to a region.

#define INCL_GPIREGIONS#include <os2.h>
void fncREGN04(void){
    POINTL ptlCurPos;      /* Mouse coordinates              */
    HPS hps;               /* Presentation-space handle      */
    HRGN hrgn;             /* Region handle                  */
    LONG lPosition;        /* Return value for GpiPtInRegion */

    /* Determine mouse coordinates and store in ptlCurPos.   */
    lPosition = GpiPtInRegion(hps, hrgn, &ptlCurPos);
    if (lPosition == PRGN_INSIDE) {
        .
        . /* Point lies within region.  */
        .
    } /* if */
    else if (lPosition == PRGN_OUTSIDE) {
        .
        . /* Point lies outside region. */
        .
    } /* else-if */