https://github.com/nilqed/cl-regis
ReGIS in Common Lisp
https://github.com/nilqed/cl-regis
common-lisp graphics-engine graphics-rendering regis
Last synced: 4 months ago
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ReGIS in Common Lisp
- Host: GitHub
- URL: https://github.com/nilqed/cl-regis
- Owner: nilqed
- License: mit
- Created: 2025-03-01T13:50:04.000Z (4 months ago)
- Default Branch: main
- Last Pushed: 2025-03-01T15:12:47.000Z (4 months ago)
- Last Synced: 2025-03-01T15:26:41.196Z (4 months ago)
- Topics: common-lisp, graphics-engine, graphics-rendering, regis
- Homepage:
- Size: 3.91 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# cl-regis
ReGIS in Common Lisp
:warning: work in progress :construction:
This is for now a prototype only inspired by https://github.com/feilipu/ReGIS.
Citing from the VT330/VT340 Graphics Programming Manual[^1]:
ReGIS is a graphics instruction set from Digital[^2]. ReGIS provides a set of commands you can use to draw images on the screen.
Of course, those terminals are hardly in use today, however, there still are some terminal emulations that support ReGIS graphics. Besides some commercial ones, we are only aware of good old **XTerm**, however, it must be compiled with `--enable-regis-graphics` contrary to **Sixel**[^3] support which is enabled by default. This is, however, no big deal (see below).
## More info about ReGIS
* https://en.wikipedia.org/wiki/ReGIS
* http://www.sizecoding.org/wiki/ReGIS
* https://vt100.net/docs/vt3xx-gp/chapter1.html
* https://en.wikipedia.org/wiki/VT320
## Compiling xterm with ReGIS support
Borrowed from https://github.com/feilipu/ReGIS:
$ sudo apt install -y libxaw7-dev libncurses-dev libxft-dev
$ wget https://invisible-island.net/datafiles/release/xterm.tar.gz
$ tar xf xterm.tar.gz
$ cd xterm-392
$ ./configure --enable-regis-graphics
$ make
$ sudo make install
Although *ReGIS, short for Remote Graphic Instruction Set*, we will not use an USART but
rather print directly to the screen with `(format ...)`.
## Testing
We will try the following two examples:
The string from https://github.com/feilipu/ReGIS:
(defvar regis-ex1 (concatenate 'string
"S(E)W(I(M))P[600,200]V[][-200,+200]V[][400,100]W(I(G))P[700,100]"
"V(B)[+050,][,+050][-050,](E)V(W(S1))(B)[-100,][,-050][+100,](E)V(W(S1,E))"
"(B)[-050,][,-025][+050,](E)W(I(C))P[200,100]C(A-180)[+100]C(A+180)[+050]"
"W(I(B))P[200,300]C(W(S1))[+100]C(W(S1,E))[+050]W(I(W))T(S02)\"hello world\""))
and the sample from Wikipedia https://en.wikipedia.org/wiki/ReGIS:
(defvar regis-ex2
"S(E)(C1)P[100,440]V(B),[+100,+0],[+0,-10],[-100,+0],(E)P[500,300],F(C[+100])")
Note that the `begin` and `end` control sequences were removed. Those have to be added, as can be seen from the following code that is used for the examples:
(defun rbeg () (format t "~C~C~C~C" #\Esc #\P #\1 #\p))
(defun rend () (format t "~C~C" #\Esc #\\))
(defun ex1 ()
(progn (rbeg)(format t "~A" regis-ex1)(rend)))
(defun ex2 ()
(progn (rbeg)(format t "~A" regis-ex2)(rend)))
Running `(ex1)`:
Running `(ex2)`:
## Goals
Mapping the instruction set in a KISS manner to CL and likely to interface with some great libraries like
VECTO[^4], CL-VECTORS[^5] and so on.
:date:
[^1]: http://bitsavers.trailing-edge.com/pdf/dec/terminal/vt340/EK-VT3XX-GP-001_VT330_VT340_Graphics_Programming_Mar87.pdf
[^2]: https://en.wikipedia.org/wiki/Digital_Equipment_Corporation
[^3]: https://github.com/nilqed/cl-sixel
[^4]: https://www.xach.com/lisp/vecto/
[^5]: https://projects.tuxee.net/cl-vectors/