## Presentation Device Driver Reference for OS/2

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### Device Context Types

The type of device to be opened is passed to the presentation driver when the device context is enabled:

OD_INFO The presentation driver does not generate any output. Information device contexts are used to retrieve information. All Grexxx function routines passed to the presentation driver are processed as if the type were OD_DIRECT. In this way, the operating system can query statistics such as font metrics and boundaries.

OD_MEMORY The presentation driver processes the output data as it does for an OD_DIRECT device type except the output is written to a bit map that is compatible with the physical device. (The application program creates the bit map and associates it to the device context.)

OD_DIRECT The presentation driver processes the Grexxx routines to generate device-specific output data. Hardcopy drivers use the file system Prtxxx interface to pass the output to the physical device driver. Display drivers use the adapter interface, such as the IBM* Personal System/2* Display Adapter 8514/A interface.

OD_QUEUED (Hardcopy drivers only.) The hardcopy driver opens a spool file and uses the spooler Splxxx interface to send output to that file. For spooled output, the hardcopy driver must consider the DC data type. See Data Types (Hardcopy Drivers Only).

Note: OD_METAFILE and OD_METAFILE_NOQUERY are handled by PMGPI.DLL and are never passed to the presentation driver.