GpiErase

This function clears the output display of the device context associated with the specified presentation space, to the reset color (CLR_BACKGROUND; see GpiSetColor).

Syntax

GpiErase(hps)

Parameters

hps (HPS) - input

Presentation-space handle.

Return Code

rc (BOOL) - returns

Success indicator.

TRUE - Successful completion

FALSE - Error occurred.

Possible returns from WinGetLastError

PMERR_INV_HPS (0x207F)

An invalid presentation-space handle was specified.

PMERR_PS_BUSY (0x20F4)

An attempt was made to access the presentation space from more than one thread simultaneously.

Example Code

Calling Sequence:

#define INCL_GPICONTROL /* Or use INCL_GPI, INCL_PM, Also in COMMON section */
#include <os2.h>

HPS     hps;  /*  Presentation-space handle. */
BOOL    rc;   /*  Success indicator. */

rc = GpiErase(hps);

This example uses the GpiErase function to clear the display before drawing.

#define INCL_GPICONTROL         /* GPI control Functions        */
#include <os2.h>

HPS hps;                /* presentation space handle            */
POINTL ptlStart = { 0, 0 }; /* start point                      */
POINTL ptlTriangle[] = { 100, 100, 200, 0, 0, 0 }; /* vertices  */

GpiErase(hps);                        /* clear the display */
GpiMove(hps, &ptlStart);              /* draw a triangle   */
GpiPolyLine(hps, 3L, ptlTriangle);

Remarks

This operation is independent of the draw controls; see GpiSetDrawControl.

The call is subject to all clipping currently in force; that is, clip path, viewing limits, graphics field, clip region, and visible region.

This function does not perform any bounds collection, or correlation.

Note: This function must not be used when creating metafiles conforming to System Application Architecture (SAA) guidelines; see "MetaFile Resolutions" in the Presentation Manager Programming Guide and Reference for more information.

Related Functions

• GpiCreateLogColorTable
• GpiSelectPalette
• GpiSetColor
• GpiSetDrawControl