See https://github.com/inconvergent/weir instead
This library is specifically written to be useful for a broad range of ways in which I create art using various generative algorithms.
In short snek
is four things:
A simple (graph) data structure for working with vertices and edges The
structure is named snek
; the name is explained below. This structure is
combined with a programming pattern for applying changes to the structure.
The pattern relies on alterations
, see below.
A series of useful data structures and tools. E.g. a 2D vector vec
, a
package for generating different kinds of random numbers: rnd
, as well as
tools for handling colors (pigment
), splines (bzspl
), and various vector
an path functionality (math
, lin-path
).
A tool for drawing things called sandpaint
. sandpaint
uses random
sampling to draw its primitives. This creates a fairly distinct and gritty
look in many cases.
A tool for drawing svg files (draw-svg
). Mainly svg files that are good
for plotting.
A while back someone on Twitter suggested that if Python 3 was named "snek" it
would avoid naming confusion. I found that amusing at the time, and picked
snek
as the placeholder name for this project. I've been looking for a better
name, but I haven't found one yet.
The pattern depends on the concept of alterations
. In short: an alteration
is a change that will be applied to the structure at the end of a given
context. alterations
are further described in
https://inconvergent.net/2017/snek-is-not-an-acronym/.
I have also written about things related to snek
at
snek
)Here is and example of manipulating a snek
instance called snk
using
alterations
. Alteration constructors are postfixed with ?
.
; context start
(snek:with (snk)
; iterate vertices
(snek:itr-verts (snk v)
; move alteration
(snek:move-vert? v (rnd:in-circ 1d0))
; w will be an arbitrary
; vertex in snk
(snek:with-rnd-vert (snk w)
; join v and w if they are closer than d
(if (< (snek:edge-length snk v w) d)
; join vertices alteration
(snek:add-edge? v w))))
; context end
; alterations have been applied
You can also manipulate the state directly. These functions are postfixed with
!
. Eg. (snek:move-vert! ...)
.
There are some examples included. All examples are in the examples
folder.
If you don't provide a filename (with full or relative path) as the first
argument, the resulting file will be named ./tmp.png
.
You can define your own arbitrary alterations. There is an example of this in
ex/custom-alt.lisp
. I have also written about it here:
https://inconvergent.net/2017/arbitrary-alterations/
I use snek for most of the work that I post online (https://twitter.com/inconvergent). Both for generating raster images as well as vector images for plotter drawings.
Here are some plotted examples:
This code requires libpng-dev
, Quicklisp
, zpng
, cl-svg
and cl-png
.
The path to quicklisp must be set in src/load
. zpng
, cl-svg
and cl-png
are automatically installed via quicklisp
.
There are some tests included, see the test
folder.
This code is highly experimental on my part. It is likely to change with no
warning or explanation. I will keep a note of the version number in
src/load.lisp
.
I would like to thank:
Who have provided me with useful hints and code feedback.