AutoLISP
provides functions that control the low-level graphics and allow direct
access to the AutoCAD graphics screen and input devices.
The grtext function
displays text directly in the status or menu areas, with or without
highlighting. The grdraw function draws
a vector in the current viewport with control over color and highlighting.
The grvecs function draws
multiple vectors.
NoteBecause these functions
depend on code in AutoCAD, their operation can be expected to
change from release to release. There is no guarantee that applications
calling these functions will be upward compatible. Also, they depend
on current hardware configurations. In particular, applications
that call grtext are not likely
to work the same on all configurations unless the developer is very careful
to use them as described (see the Customization Guide)
and to avoid hardware-specific features. Finally, because they are
low-level functions, they do almost no error reporting and can alter
the graphics screen display unexpectedly (see the following example
for a way to fix this).
The
following sequence restores the default graphics window display
caused by incorrect calls to grtext, grdraw, or grvecs:
(grtext) Restores
standard text
(redraw)
