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.
[Back: Device Context]
[Next: Data Types (Hardcopy Drivers Only)]