GrePtInRegion

GrePtInRegion checks whether a point lies within a region. GrePtInRegion raises an error when hrgn is the handle of the currently selected clip region. The point is always expected in device coordinates.

This function can be hooked by the presentation driver.

Simulation support

This function is simulated by a handling routine in the graphics engine.

Syntax

GrePtInRegion(hdc, hrgn, pptlPoint, pInstance, lFunction)

Parameters

hdc (HDC) - input

Device context handle.

hrgn (HRGN) - input

Region handle.

pptlPoint (PPOINTL) - input

Pointer to (x, y) point specified in device coordinates.

pInstance (PVOID) - input

Pointer to instance data.

lFunction (ULONG) - input

High-order WORD=flags; low-order WORD=NGrePtInRegion.

Return Code

rc (LONG) - returns

Return codes.

This function returns an integer (lInside) indicating whether the point is inside the region:

• RGN_ERROR Error
• PRGN_INSIDE In region
• PRGN_OUTSIDE Not in region.

Possible Errors Detected: When an error is detected, the handling routine must call WinSetErrorInfo to post the condition. Error codes for conditions that the handling routine is expected to check include:

• PMERR_HRGN_BUSY
• PMERR_INV_COORDINATE
• PMERR_INV_HRGN
• PMERR_INV_RECT
• PMERR_REGION_IS_CLIP_REGION

Refer to the "Error Explanations" section in the Presentation Manager Programming Reference for further explanation.

Declaration

#define INCL_GRE_REGIONS
#include <os2.h>

HDC        hdc;        /*  Device context handle. */
HRGN       hrgn;       /*  Region handle. */
PPOINTL    pptlPoint;  /*  Pointer to (x, y) point specified in device coordinates. */
PVOID      pInstance;  /*  Pointer to instance data. */
ULONG      lFunction;  /*  High-order WORD=flags; low-order WORD=NGrePtInRegion. */
LONG       rc;         /*  Return codes. */

rc = GrePtInRegion(hdc, hrgn, pptlPoint, pInstance, lFunction);