GreSetViewingLimits

GreSetViewingLimits sets the boundaries of the viewing (clip) limits in model space to the specified values.

This function can be hooked by the presentation driver.

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

Syntax

GreSetViewingLimits(hdc, prclViewingLimits, pInstance, lFunction)

Parameters

hdc (HDC) - input

Device context handle.

prclViewingLimits (PRECTL) - input

Pointer to limits of viewing area.

RECTL structure:

xLeft Minimum :X-coordinate of viewing limits

yBottom Minimum: Y-coordinate

xRight Maximum: X-coordinate of viewing limits

yTop Maximum: Y-coordinate

pInstance (PVOID) - input: Pointer to instance data.
lFunction (ULONG) - input: High-order WORD=flags; low-order WORD=NGreSetViewingLimits.

Returns

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_COORDINATE
PMERR_INV_GRAPHICS_FIELD
PMERR_INV_HDC
PMERR_INV_IN_AREA
PMERR_INV_IN_PATH

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

Sample

#define INCL_GRE_XFORMS
#include <os2.h>

HDC       hdc;                /*  Device context handle. */
PRECTL    prclViewingLimits;  /*  Pointer to limits of viewing area. */
PVOID     pInstance;          /*  Pointer to instance data. */
ULONG     lFunction;          /*  High-order WORD=flags; low-order WORD=NGreSetViewingLimits. */
BOOL      fSuccess;           /*  Return codes. */

fSuccess = GreSetViewingLimits(hdc, prclViewingLimits,
             pInstance, lFunction);

Remarks

This function sets the boundaries of the viewing (clip) limits in model space to the specified values. The boundaries are inclusive and are not clipped. The viewing-limit coordinates are transformed to make a clipping rectangle in page-coordinate or device-coordinate space. Any rotation or shear of this rectangle is ignored. When the left boundary is greater than the right, or the bottom boundary is greater than the top, a NULL rectangle is defined and all points are clipped.