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WORD Control(lpDestDev, wFunction, lpInData, lpOutData)
LPPDEVICE lpDestDev;
WORD wFunction;
LPSTR lpInData;
LPSTR lpOutData;
 
The Control function carries out the device-specific extension specified by
the wFunction parameter. GDI calls Control when an application calls the
Escape function (GDI.38). For this reason, the device-specific extensions
are also called escapes.
 
Every graphics driver must export a Control function.
 
Parameter  Description
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lpDestDev  Points to a PDEVICE structure specifying the destination device.
 
wFunction  Specifies the escape to carry out. Although the number of
           wFunction values and the meaning of each value depends on the
           driver, GDI reserves a number of values to specify predefined
           escapes. For more information about predefined escapes, see
           Chapter 11, "Graphics-Driver Escapes."
 
lpInData   Points to escape-specific input data.
 
lpOutData  Points to escape-specific output data.
 
Return Value
 
The return value depends on the escape function specified by the wFunction
parameter. In general, positive values indicate success, negative values
indicate an error, and zero can indicate either an unimplemented escape or a
general error condition.
 
Comments
 
The export ordinal for this function is 3.
 
The Control function should always return zero for escapes that are
unimplemented or unrecognized. The function should return the number of
bytes copied if it copies data to a buffer pointed to by the lpOutData
parameter, or if the lpOutData parameter is NULL, it should return the size
in bytes of the buffer it requires to copy data.
 
GDI modifies some escapes before calling the Control function.
 
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