XSLT-Perlin2D

A 2D perlin noise SVG generator using XSLT 2.0 and self loathing.

Its ugly, slow, and I'm sorry for bringing it into existence.

Build

• This was actually a huge pain to figure out which XSLT processor to use (xalan, saxon, xsltproc, etc)
• I ended up doing something gross. I used Apache Ant and Saxon9.
• To build with Saxon9 (XSLT 2.0) use ant Recommended
• Can also be built with XALAN (XSLT 1.0) use groovy build-xalan.groovy but its runs terribly at greater than 128x128 size

Generated SVG

Input XML (perlin-svg.xml)

<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet href="perlin.xslt" type="text/xsl"?>
<perlin-noise>
  <settings>
    <sizeX>256</sizeX>
    <sizeY>256</sizeY>
    <seed>1234</seed>
    <frequency>6</frequency>
    <octaves>4</octaves>
  </settings>
</perlin-noise>

Generated Perlin noise XML example-perlin.xml

Sample of perlin noise data that is generated before transforming to SVG.

Output SVG perlin.svg

<?xml version="1.0" encoding="UTF-8"?>
<svg xmlns="http://www.w3.org/2000/svg" width="256" height="256" viewBox="0 0 256 256">
  <rect x="1" y="1" width="1" height="1" fill="rgb(66,66,66)"/>
  <rect x="2" y="1" width="1" height="1" fill="rgb(61,61,61)"/>
  <rect x="3" y="1" width="1" height="1" fill="rgb(180,180,180)"/>
  <rect x="4" y="1" width="1" height="1" fill="rgb(160,160,160)"/>
  <!-- ... -->
</svg>

XSLT Descriptions

File Name	Description
hash.xslt	Pre-computed hashes for generating perlin noise
map.xslt	Create map data structure of pixels
noise.xslt	Generate 2D Perlin noise
perlin-svg.xslt	Driver
svg-utils.xslt	Utils for SVG generation and color value conversion
utils.xslt	General utils

Sources

• Ken Perlin's implementation http://mrl.nyu.edu/~perlin/noise/
• https://en.wikipedia.org/wiki/Perlin_noise
• https://codepen.io/shshaw/post/vector-pixels-svg-optimization-animation-and-understanding-path-data