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GreIntersectClipRectangle sets the new clipping region to the intersection of the current clip region and the specified rectangle.  
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.  
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.  
;Simulation support: This function is simulated by a handling routine in the graphics engine.


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


==Parameters==
==Parameters==
;hdc (HDC) - input  
;hdc (HDC) - input:Device context handle.
:Device context handle.  
;prclRect (PRECTL) - input:Pointer to rectangle ([[RECTL]] structure) in world or device coordinates.
 
;pInstance (PVOID) - input:Pointer to instance data.
;prclRect (PRECTL) - input  
;lFunction (ULONG) - input:High-order WORD=flags; low-order WORD=NGreIntersectClipRectangle.
:Pointer to rectangle (RECTL structure) in world or device coordinates:
 
:*xLeft Minimum x-coordinate of rectangle
:*yBottom Minimum y-coordinate
:*xRight Maximum x-coordinate of rectangle
:*yTop Maximum y-coordinate All the boundaries of the rectangle are inclusive (part of the interior) and are not clipped. If COM_TRANSFORM is not set, the function expects the rectangle to be in device coordinates.  
 
;pInstance (PVOID) - input  
:Pointer to instance data.  
 
;lFunction (ULONG) - input  
:High-order WORD=flags; low-order WORD=NGreIntersectClipRectangle.  


==Return Code==
==Return Code==
;rc (LONG) - returns  
;rc (LONG) - returns:Return codes.
:Return codes.  
:This function returns an integer (lComplexity) indicating the complexity of the DC region:
 
:*RGN_ERROR Error
:This function returns an integer (lComplexity) indicating the complexity of the DC region:  
:*RGN_NULL Null region
 
:*RGN_RECT Rectangular region
:*RGN_ERROR Error  
:*RGN_COMPLEX Complex region (more than 1 rectangle)
:*RGN_NULL Null 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:
:*RGN_RECT Rectangular region  
:*PMERR_COORDINATE_OVERFLOW
:*RGN_COMPLEX Complex region (more than 1 rectangle)  
:*PMERR_DEV_FUNC_NOT_INSTALLED
 
:*PMERR_HDC_BUSY
: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_INSUFFICIENT_MEMORY
 
:*PMERR_INV_COORD_SPACE
:*PMERR_COORDINATE_OVERFLOW  
:*PMERR_INV_COORDINATE
:*PMERR_DEV_FUNC_NOT_INSTALLED  
:*PMERR_INV_HDC
:*PMERR_HDC_BUSY  
:*PMERR_INV_HRGN
:*PMERR_INSUFFICIENT_MEMORY  
:*PMERR_INV_IN_AREA
:*PMERR_INV_COORD_SPACE  
:*PMERR_INV_IN_PATH
:*PMERR_INV_COORDINATE  
:*PMERR_INV_LENGTH_OR_COUNT
:*PMERR_INV_HDC  
:*PMERR_INV_RECT
:*PMERR_INV_HRGN  
:*PMERR_INV_REGION_CONTROL
:*PMERR_INV_IN_AREA  
:Refer to the "Error Explanations" section in the ''Presentation Manager Programming Reference'' for further explanation.
:*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==
==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.  
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==
==Sample Code==
Line 63: Line 45:
#include <os2.h>
#include <os2.h>


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


rc = GreIntersectClipRectangle(hdc, prclRect,
rc = GreIntersectClipRectangle(hdc, prclRect, pInstance, lFunction);
      pInstance, lFunction);
</PRE>
</PRE>


[[Category:Gre]]
[[Category:Gre]]

Latest revision as of 17:35, 7 February 2020

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

#define INCL_GRE_CLIP
#include <os2.h>

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);
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