GreGetDCOrigin

GreGetDCOrigin queries the origin of the device context that defines the bottom-left drawing origin for a display device or a banded hardcopy device.

This function must be supported by presentation drivers for display devices and for hardcopy devices that use banding. For other devices, the minimum requirement is for the handling routine to return Successful with pptlOrigin set to (0,0).

Simulation support

None. This function is mandatory for all drivers.

Syntax

GreGetDCOrigin(hdc, pptlOrigin, pInstance, lFunction)

Parameters

hdc (HDC) - input

Device context handle.

pptlOrigin (PPOINTL) - input

Pointer to the (X,Y) coordinates of the returned DC origin in screen coordinates.

pInstance (PVOID) - input

Pointer to instance data.

lFunction (ULONG) - input

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

Return Code

rc (BOOL) - returns

Return Code.

On completion, the handling routine must return a BOOLEAN value to indicate success or an error.

• TRUE Successful
• FALSE Error

Remarks

The DC origin is set by GreSetupDC (see GreSetupDC) at the graphics engine, and by GreDeviceSetDCOrigin (see GreDeviceSetDCOrigin) at the presentation driver. This device context origin is stored in the Device Context Instance (DCI) data structure addressed by pInstance. The DC origin is always returned in screen coordinates.

Sample Code

#define INCL_GRE_DEVMISC3
#include <os2.h>

HDC        hdc;         /*  Device context handle. */
PPOINTL    pptlOrigin;  /*  Pointer to the (X,Y) coordinates of the returned DC origin in screen coordinates. */
PVOID      pInstance;   /*  Pointer to instance data. */
ULONG      lFunction;   /*  High-order WORD=flags; low-order WORD=NGreGetDCOrigin. */
BOOL       rc;          /*  Return Code. */

rc = GreGetDCOrigin(hdc, pptlOrigin, pInstance, lFunction);