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

#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);