View source for GetDriverInfo

This function returns a driver object handle for the engine object identified by hEngObject. 
==Syntax==
 GetDriverInfo(hEngObject, ulIndex, hdc);
==Parameters==
;hEngObject (ULONG) - input 
:Handle of a DC or bit map. 

;ulIndex (ULONG) - input 
:Has the following settings: 

::Index=0 hEngObject is a DC handle 
::Index=1 hEngObject is a bit-map handle 

;hdc (HDC) - input 
:Device context handle, which identifies the calling DC. 
==Return Code==
; rc (LONG) - returns : Return codes. 

:If successful, the function returns the instance pointer associated with the object DC or the presentation driver's handle to the object bit map. If an error is detected, the function returns GPI_ALTERROR. 

==Remarks==
The parameter hEngObject can be a DC handle or an engine bit-map handle (for example, the source handle, which would be passed to the presentation driver's GreBitblt routine). If hEngObject is a DC, the return code is a pointer (pInstance) to the instance data of that DC. If hEngObject is a bit map, the return code is the driver's handle for the bit map (that is the handle returned to the presentation driver when the bit map was created). 

GetDriverInfo includes a check to ensure that the object is, or was created by, an instance of a DC for the same device as the DC identified by hdc. If the check is not successful, the function returns GPI_ALTERROR. GetDriverInfo is exported by the graphics engine at ordinal 30 and, if the presentation driver wants to call this function, it must be imported by the driver's module definition file. 

==Example Code==
<PRE>
#include <os2.h>

ULONG    hEngObject;  /*  Handle of a DC or bit map. */
ULONG    ulIndex;
HDC      hdc;         /*  Device context handle, which identifies the calling DC. */
LONG     rc;          /*  Return codes. */

rc = GetDriverInfo(hEngObject, ulIndex, hdc);
</PRE>


[[Category:Gre]]