GreQueryClipRegion

GreQueryClipRegion returns the handle of the currently selected clip region, or NULL (if none exists).

This function can be hooked by the presentation driver.


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

Syntax
GreQueryClipRegion(hdc, pInstance, lFunction);

Parameters

 * hdc (HDC) - input
 * Device context handle.


 * pInstance (PVOID) - input
 * Pointer to instance data.


 * lFunction (ULONG) - input
 * High-order WORD=flags; low-order WORD=NGreQueryClipRegion.

Return Code

 * rc (HRGN) - returns
 * This function returns the handle of the clip region:


 * hrgn Region handle
 * NULL Null handle (no region selected)
 * HRGN_ERROR Error


 * 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_HDC_BUSY
 * PMERR_INV_HDC


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

Sample Code



 * 1) define INCL_GRE_CLIP
 * 2) include 

HDC     hdc;        /*  Device context handle. */ PVOID   pInstance;  /*  Pointer to instance data. */ ULONG   lFunction;  /*  High-order WORD=flags; low-order WORD=NGreQueryClipRegion. */ HRGN    rc;         /*  This function returns the handle of the clip region: */

rc = GreQueryClipRegion(hdc, pInstance, lFunction); 