There was a graphics standard extension named GSX for few CP/M computer
After I bought a Commodore C128, I started to play with CP/M 3.0 very soon, see here also.
I realized that there are many CP/M text applications, but almost no graphics applications.
It exists only one standardized graphics interface for CP/M, GSX-80.
But you have to use a device dependent screen driver for each computer.
Unfortunately Commodore never developed such one, so building such one is one of my ideas I had.
To get in touch with GSX-80, you need only the Programmers Manual (and the Users Manual for a general overview).
I've converted a GSX-80/GSX-86 related programmers manuals to a modern document format here: GSX-PGR.PDF
More GSX-related stuff will follow as I have time for that...
Because starting from scratch in this matter is very hard, I looked for
a Graphics Library for the C128 usable with CP/M, and fortunately I
SG C TOOLS from Steve Goldsmith.
Look at this screenshots and you will see what can be done with it...
Here are the compiled files (done with HITECH C):
demo1.pcx - file will be loaded from the main program
demo2.pcx - file will be loaded from the main program
And here is the source code: demo.c
You need also the library (v1.6) itself: libc128.arc
This is the ReadMe-Document which was also included: sgctools.txt
And last, but not least you need the HiTech C Compiler 3.09 - download it here as a ZIP archive.
NEW: Steven Goldsmith has published instructions how to compile it. Also, he published a never seen v1.8 of it (and he included a floppy disk image also).
A different approach was published from a german Commodore Magazine, a
library which can be used with TURBO PASCAL 3, also under CP/M 3.
This is included in the archive file graph128.zip, more infos will follow...