View source for GreSetWindowViewportXform

GreSetWindowViewportXform sets the window or viewport transform matrix elements as specified. 

This function can be hooked by the presentation driver. 

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

== Syntax == 
 GreSetWindowViewportXform(hdc, paXformData, flOptions, pInstance, lFunction);

== Parameters ==
; hdc (HDC) - input : Device context handle. 

; paXformData (PXFORM) - input : Pointer to an array. 
: Pointer to an array of six matrix elements for two-dimensional formation. These are M11, M12, M21, M22, M41, and M42. 

; flOptions (LONG) - input : Specifies how the supplied array should be used to set the matrix. 

: Valid values are: 
:*SX_UNITY Set unity transform. Ignore array values. 
:*SX_CAT_AFTER Concatenate after. 
:*SX_CAT_BEFORE Concatenate before. 
:*SX_OVERWRITE Overwrite. 

; pInstance (PVOID) - input : Pointer to instance data. 

; lFunction (ULONG) - input : High-order WORD=flags; low-order WORD=NGreSetWindowViewportXform. 

== Returns ==
; fSuccess (BOOL) - returns : Return codes. 

This function returns BOOLEAN (fSuccess). 

* TRUE Successful 
* FALSE 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_BASE_ERROR 
*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_MATRIX_ELEMENT 
*PMERR_INV_PATTERN_REF_PT_ATTR 
*PMERR_INV_PICK_APERTURE_POSN 
*PMERR_INV_RECT 
*PMERR_INV_REGION_CONTROL 
*PMERR_INV_TRANSFORM_TYPE 
*PMERR_PATH_LIMIT_EXCEEDED 

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


== Sample ==
<pre>
#define INCL_GRE_XFORMS
#include <os2.h>

HDC       hdc;          /*  Device context handle. */
PXFORM    paXformData;  /*  Pointer to an array. */
LONG      flOptions;    /*  Specifies how the supplied array should be used to set the matrix. */
PVOID     pInstance;    /*  Pointer to instance data. */
ULONG     lFunction;    /*  High-order WORD=flags; low-order WORD=NGreSetWindowViewportXform. */
BOOL      fSuccess;     /*  Return codes. */

fSuccess = GreSetWindowViewportXform(hdc,
             paXformData, flOptions, pInstance,
             lFunction);
</pre>

[[Category:Gre]]