GreOffsetClipRegion

GreOffsetClipRegion moves the clipping region by the specified amount.

This function is supported by the graphics engine and can be hooked by the presentation driver.

Simulation support

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

Syntax

GreOffsetClipRegion(hdc, pdpt, pInstance, lFunction)

Parameters

hdc (HDC) - input

Device context handle.

pdpt (PPOINTL) - input

Pointer to offset by which the clipping region is to be moved, in world coordinates:

• dx X offset
• dy Y offset

pInstance (PVOID) - input

Pointer to instance data.

lFunction (ULONG) - input

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

Return Code

rc (LONG) - returns

Return codes.

This function returns an integer (lComplexity) indicating the complexity of the region:

• RGN_ERROR Error
• RGN_NULL Null region
• RGN_RECT Rectangular region
• RGN_COMPLEX Complex region (more than 1 rectangle)

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_COORDINATE_OVERFLOW
• PMERR_DEV_FUNC_NOT_INSTALLED
• PMERR_HDC_BUSY
• PMERR_INSUFFICIENT_MEMORY
• PMERR_INV_COORD_OFFSET
• PMERR_INV_COORD_SPACE
• PMERR_INV_COORDINATE
• PMERR_INV_HDC
• PMERR_INV_HRGN
• PMERR_INV_IN_AREA
• PMERR_INV_IN_PATH
• PMERR_INV_LENGTH_OR_COUNT
• PMERR_INV_RECT
• PMERR_INV_REGION_CONTROL

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

Remarks

The value returned is the complexity of the resultant DC region, that is, the intersection of all clipping (such as clip path, viewing limits, graphics field, clip region, and visible region).

Sample Code

#define INCL_GRE_CLIP
#include <os2.h>

HDC        hdc;        /* Device context handle. */
PPOINTL    pdpt;       /* Pointer to offset. */
PVOID      pInstance;  /* Pointer to instance data. */
ULONG      lFunction;  /* High-order WORD=flags; low-order WORD=NGreOffsetClipRegion. */
LONG       rc;         /* Return codes. */

rc = GreOffsetClipRegion(hdc, pdpt, pInstance, lFunction);