GreSaveXform

GreSaveXform is called during SaveDC and OpenDC to allow simulations to save their local data structures. A Save with a count of one more than the current save level generates intervening levels. When a new DC is created, GreSaveXform is called with a count of 1 to initialize its local data.

This function can be hooked by the presentation driver.

Simulation support

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

Syntax

GreSaveXform(hdc, cSave, pInstance, lFunction)

Parameters

hdc (HDC) - input

Device context handle.

cSave (LONG) - input

DC save level. This must not be a negative value.

pInstance (PVOID) - input

Pointer to instance data.

lFunction (ULONG) - input

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

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_INSUFFICIENT_MEMORY
• PMERR_INV_HDC.

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

Remarks

When initializing a new DC, the default transform must be set.

Sample Code

#define INCL_GRE_XFORMS
#include <os2.h>

HDC      hdc;        /*  Device context handle. */
LONG     cSave;      /*  DC save level. This must not be a negative value. */
PVOID    pInstance;  /*  Pointer to instance data. */
ULONG    lFunction;  /*  High-order WORD=flags; low-order WORD=NGreSaveXform. */
BOOL     fSuccess;   /*  Return codes. */

fSuccess = GreSaveXform(hdc, cSave, pInstance, lFunction);