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.