## Presentation Device Driver Reference for OS/2

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### GreGetClipBox - Syntax

Simulation support:

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

Description

GreGetClipBox determines the dimensions of the tightest rectangle around the DC region in world coordinates. The DC region is defined as the intersection of the visible region, clip region, viewing limits, graphics field, and clip path. The bounding rectangle is inclusive. Points on its boundary are deemed to be inside it. If COM_TRANSFORM is not set, the rectangle points are returned in screen coordinates.

This function can be hooked by the presentation driver.

    #define INCL_GRE_CLIP

    #include <os2.h>

    HDC       hdc;        /*  Device context handle. */

    PRECTL    prclRect;   /*  Pointer to rectangle in world or screen coordinates. */

    PVOID     pInstance;  /*  Pointer to instance data. */

    ULONG     lFunction;  /*  High-order WORD=flags; low-order WORD=NGreGetClipBox. */

    LONG      rc;         /*  Return codes. */

    rc = GreGetClipBox(hdc, prclRect, pInstance,

           lFunction);