## Presentation Device Driver Reference for OS/2

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### GrePtVisible

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    Syntax
    Parameters
    Returns
    Glossary

Simulation support:

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

Description

GrePtVisible checks whether a point is visible within the DC region of the specified device context. The "DC region" is defined as the intersection of the application clipping and the window clipping.

This function can be hooked by the presentation driver.

    #define INCL_GRE_CLIP

    #include <os2.h>

    HDC        hdc;        /*  Device context handle. */

    PPOINTL    pptlPoint;  /*  Pointer to (X,Y) point in world or screen coordinates. */

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

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

    LONG       rc;         /*  Return codes. */

    rc = GrePtVisible(hdc, pptlPoint, pInstance,

           lFunction);