GreSetProcessControl

GreSetProcessControl provides a mechanism to control drawing, boundary computation, and correlation.

This function is supported by the graphics engine.

Syntax

GreSetProcessControl(hdc, flMask, flProcess, pInstance, lFunction)

Parameters

hdc (HDC) - input

Device context handle.

flMask (ULONG) - input

Only those flags with the corresponding bit in this parameter set are modified.

flProcess (ULONG) - input

Indicates which process-control flags to set.

Process-control flags:

PCTL_DRAW

Has no effect on GreErasePS. If set, drawing primitives should appear on screen. Otherwise, output operations such as GreBitblt, GrePaintRegion, GreSetPel and other drawing primitives are not displayed.

PCTL_BOUND

Set to indicate that GPI_BOUNDS must be accumulated.

PCTL_CORRELATE

Set to indicate that correlation is to be done.

PCTL_USERBOUNDS

When set, indicates that USER_BOUNDS are to be collected for the window manager.

pInstance (PVOID) - input

Pointer to instance data.

lFunction (ULONG) - input

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

Return Code

fSuccess (BOOL) - returns

Return codes.

On completion, the handling routine must return BOOLEAN (fSuccess).

• TRUE Successful
• FALSE Error

Possible Errors Detected: When an error is detected, the graphics engine calls WinSetErrorInfo to post the condition. Reasons for failure of this function include:

• PMERR_HDC_BUSY
• PMERR_INV_HDC

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

Remarks

Bounds are returned in graphics model-space coordinates. If a composite transform is applied to the drawing primitives, the bounds values must be transformed back to their original values before merging with the previous bounds values.

Correlation is performed in page-coordinate space on the output of primitives that have been clipped only to the viewing limits and graphics field. Note that correlation is performed for all functions except alphanumeric functions and GreErasePS. Boundary computation is performed for all functions except GreErasePS.

Sample Code

#define INCL_GRE_DCS
#include <os2.h>

HDC      hdc;        /*  Device context handle. */
ULONG    flMask;
ULONG    flProcess;  /*  Indicates which process-control flags to set. */
PVOID    pInstance;  /*  Pointer to instance data. */
ULONG    lFunction;  /*  High-order WORD=flags; low-order WORD=NGreSetProcessControl. */
BOOL     fSuccess;   /*  Return codes. */

fSuccess = GreSetProcessControl(hdc, flMask,
             flProcess, pInstance, lFunction);