GreExcludeClipRectangle

GreExcludeClipRectangle excludes the specified rectangle from the clipping region, that is, the area covered by the rectangle will be outside the resulting clip region. If COM_TRANSFORM is not set, the function expects the rectangle points to be in device coordinates. GreExcludeClipRectangle creates a clip region when none exists. The application is responsible for deleting this clip region when it is finished. Otherwise, it is not deleted until the DC is closed.

This function can be hooked by the presentation driver.

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

Syntax

GreExcludeClipRectangle(hdc, prclRect, pInstance, lFunction)

Parameters

hdc (HDC) - input: Device context handle.
prclRect (PRECTL) - input: Pointer to rectangle in world or device coordinates.
pInstance (PVOID) - input: Pointer to instance data.
lFunction (ULONG) - input: High-order WORD=flags; low-order WORD=NGreExcludeClipRectangle.

Returns

rc (LONG) - returns

Return codes.

This function returns an integer (lComplexity) indicating the complexity of the DC region:

RGN_ERROR Error
RGN_NULL Null region
RGN_RECT Rectangular region
RGN_COMPLEX Complex region (more than 1 rectangle)

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_COORDINATE_OVERFLOW
PMERR_DEV_FUNC_NOT_INSTALLED
PMERR_HDC_BUSY
PMERR_INSUFFICIENT_MEMORY
PMERR_INV_COORD_SPACE
PMERR_INV_COORDINATE
PMERR_INV_HDC
PMERR_INV_HRGN
PMERR_INV_IN_AREA
PMERR_INV_IN_PATH
PMERR_INV_LENGTH_OR_COUNT
PMERR_INV_RECT
PMERR_INV_REGION_CONTROL

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

Sample

#define INCL_GRE_CLIP
#include <os2.h>

HDC       hdc;        /*  Device context handle. */
PRECTL    prclRect;   /*  Pointer to rectangle in world or device coordinates. */
PVOID     pInstance;  /*  Pointer to instance data. */
ULONG     lFunction;  /*  High-order WORD=flags; low-order  WORD=NGreExcludeClipRectangle. */
LONG      rc;         /*  Return codes. */

rc = GreExcludeClipRectangle(hdc, prclRect, pInstance, lFunction);