GreGetWindowViewportXform

GreGetWindowViewportXform queries the current window or viewport transform matrix. On completion, paXformData is an array of two-dimensional values defining the current window or viewport transform matrix.

This function can be hooked by the presentation driver.

Simulation support

This function is simulated by a handling routine in the graphics engine.

Syntax

GreGetWindowViewportXform(hdc,paXformData, pInstance, lFunction);

Parameters

hdc (HDC) - input

Device context handle.

paXformData (PXFORM) - input

Pointer to return data.

Pointer to return data in which the array of six matrix elements (M11, M12, M21, M22, M41, and M42) are to be stored.

pInstance (PVOID) - input

Pointer to instance data.

lFunction (ULONG) - input

High-order WORD=flags; low-order WORD=NGreGetWindowViewportXform.

Return Code

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_HDC_BUSY
• PMERR_INV_HDC

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

Declaration

#define INCL_GRE_XFORMS
#include <os2.h>

HDC       hdc;          /*  Device context handle. */
PXFORM    paXformData;  /*  Pointer to return data. */
PVOID     pInstance;    /*  Pointer to instance data. */
ULONG     lFunction;    /*  High-order WORD=flags; low-order WORD=NGreGetWindowViewportXform. */
BOOL      fSuccess;     /*  Return codes. */

fSuccess = GreGetWindowViewportXform(hdc,
             paXformData, pInstance, lFunction);