DCL:GRPH1:SWPACK: Machine-Dependent Routines
The SWPACK is a group of machine-dependent routines in the GRPH1 library at
the lowest level. In the SWPACK, only the standards for the higher interfaces
are defined, and the actual operations and the internal structures are
There are the "basic functions" and the "extended functions" in the SWPACK. The basic functions can be executed (or assumed as possible) by all devices, but the extended functions may not be executable in some devices.
A higher routine may not be able to use extended functions, so coating
must be performed. To check whether these functions can be used, use the inquiry
routines of SWPACK.
On the GRPH1 level, the switching between line width and color is carried out
depending on the capacity of the device. For devices that cannot perform hard
fill, the fill routine automatically performs soft fill.
As there are no alternative routines for the image display and pointing
functions, the user must be careful when using them.
In the SWPACK, the machine-dependent internal variable can be inquired/changed by swpget/swpset
(integer variable, floating-point variable, logical variable) and swcget/swcset
(character variable). However, the internal variables handled by swpget/swpset
and swcget/swcset, are all read only once when the device is opened and
are not inquired again, so swpset and swcset must be called before calling
Section 7.8 provides an explanation of the
internal variables for the graphics output devices provided in the standard DCL
library (X-server, postscript, Tek terminal). The internal variables defined are