RXGRAPH.ARC

Author: Bill Mayne
9707 Lawndale Dr.
Silver Spring, MD 20901

Comments, suggestions, and enhancements are welcome.

This archive contains a user written low level graphics interface for
Personal Rexx. RXGRAPH must be executed before any Rexx programs which
call it. It is a TSR routine which adds several functions as built in
functions for Rexx. The actual graphics functions may also be used by C
programs which have nothing to do with REXX.

Rexx functions defined:

get_mode - get the current video mode (mainly to be able to
restore it later.)
set_mode - set the video mode (graphics supported for 4 thru 6)
set_background - set the background color (0 thru 15)
set_pallette - select the color pallette (0 or 1)
put_dot - write one pixel
get_dot - read one pixel
draw_line - plot a line, using pixel coordinates
scr_fill - fill the entire screen with a given color
(only if using direct memory writes - much faster
than plotting individual dots or lines)

For examples of use see the .REX files in this archive.

Compiling instructions:

For the main routine, RXGRAPH.C compile by:

msc rxgraph /Zp /Ox;

The /Zp options specifies that structures be packed, and is necessary
for the Rexx interface to work. The /Ox option calls for maximum
optimization, and is recommended but not required. You must have
REXXCALL.H and the .H files from this archive in a directory where the
compiler can find them.

Several modules (including RXGRAPH.C) also support the /DBIOS option to
use BIOS calls instead of direct memory writes when plotting. This is
considerably faster (about 1.9 times as fast when plotting lines).
Note, however, that Rexx programs should make sure to use BIOS calls for
character output while in graphics modes.

All other routines are compiled normally. The /Ox option is recommended
and in some cases .H files from this archive are required.

Link as follows:

link rxgraph,,,bitmap+rxgraph
exemod rxgraph /max 100

The library rxgraph includes not only rxgraph.obj, but findint.obj and
rexxfcn.obj, required for the Rexx interface.

The EXEMOD call reduces the amount of memory used. You may experiment
with going lower. Generally if you go too low the result is that REXX
acts as if the functions defined are not found.