## Presentation Device Driver Reference for OS/2

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### GreEscape DEVESC_EXTGET

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    Syntax
    Parameters
    Returns
    Remarks
    Glossary

Simulation support:

None.

Description

GreEscape DEVESC_EXTGET is called by EnDIVE users to copy an image from the screen to system memory or to off-screen video memory. This function should be called only when the image needs to be returned in a compressed format. If the hardware does not support compression, then this call should not be implemented.

The various compression formats supported by the hardware are returned in the GreEscape DEVESC_EXTQUERY function.

Users of this function are responsible for bracketing access to video memory and this function with GreEscape DEVESC_HWREQUEST.

    #define INCL_GRE_DEVICE

    #include <os2.h>

    HDC      hdc;         /*  Device context handle. */

    LONG     ICODE;       /*  DEVESC_EXTGET escape code. */

    LONG     lInCount;    /*  Number of bytes pointed to by pbInData. */

    PBYTE    pbInData;    /*  Pointer to IMAGEPACK data structure. */

    PLONG    plOutCount;  /*  NULL. */

    PLONG    pbOutData;   /*  NULL. */

    LONG     rc;          /*  Return Codes. */

    rc = GreEscape(hdc, ICODE, lInCount, pbInData,

           plOutCount, pbOutData);