GreIntersectClipRectangle

GreIntersectClipRectangle sets the new clipping region to the intersection of the current clip region and the specified rectangle.

This function is supported by the graphics engine and can be hooked by the presentation driver.


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

Syntax
GreIntersectClipRectangle(hdc, prclRect, pInstance, lFunction)

Parameters

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

Return Code

 * 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.

Remarks
When no clip region exists, GreIntersectClipRectangle must create one. The application must then free the handle when it subsequently selects another clip region. The return value of this function is the complexity of the resultant DC region, which is defined as the intersection of all clipping.

Sample Code

 * 1) define INCL_GRE_CLIP
 * 2) include 

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

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