Purpose
Use the HostRast option to perform
raster image processing at the System/370 host.
Use the HostRast
option when:
- Multiplane character symbol sets are required by the application.
- GDDM® color mixing is important
to the application.
The default device model for GDDMXD/MVS is an IBM® 3179G with a mouse and the raster image processing
is performed at the workstation.
Format
.-N-.
>>-gddmx*HOSTRAST--:--+---+------------------------------------><
+-Y-+
'-X-'
Parameters
- N
- Directs GDDMXD/MVS to use the IBM 3179G as a device model. This is the default.
- Y
- Directs GDDMXD/MVS to use the IBM 3279 as a device model.
- X
- Directs GDDMXD/MVS to use the IBM 3279 as a device model and expand the pixel mapping to reduce
aspect ratio distortion.
Usage
- The APL2® character set
is not supported when the HostRast option is active.
- When the HostRast option is specified as Y, the GDDM application performs the raster image processing
and transmits the picture as a series of characters whose pixel definitions
have been transmitted to Programmed Symbol Sets. The picture is mapped
exactly as an IBM 3279.
- If the ratio of horizontal to vertical pixel spacing is not the
same as that of an IBM 3279,
the aspect ratio can be distorted.