ihh / graphgram

Graph grammar library

graphgram

More complete documentation is available at the following links:

• Getting started guide
• API documentation
• JSON schema documentation

graphgram is a graph grammar library. It transforms graphlib graphs using a configurable, JSON-described graph grammar (see e.g. these slides by Matilde Marcolli, or this RPS article about Joris Dormans' Unexplored (which uses the technique to generate "cyclic" levels), or this Wikipedia page).

It can be used for game levels, procedural content, simulations, etc.

Scripts

• bin/transform.js: transform a graph using a graph grammar
• bin/lattice.js: create an N*N square lattice
• bin/graph2dot.js: the transform.js graphlib-to-Graphviz feature, as a separate script

Example grammars

• grammars/dungeon.js: choose-your-own dungeon
• grammars/level.js: a roguelike level (should be initialized with a square lattice)
• grammars/test.js: a test grammar

API usage

var graphlib = require('graphlib'),
    Grammar = require('../graphgram').Grammar,
    fs = require('fs')

var grammarFile = 'grammars/dungeon.json'
var grammarJson = JSON.parse (fs.readFileSync (grammarFile).toString())

var grammar = new Grammar (grammarJson)
var graph = grammar.evolve().graph

The resulting graph is a graphlib object.

Command-line usage

Usage: node transform.js

  -g, --grammar=PATH   read grammar file (default "grammars/dungeon.js")
  -c, --canonical      use canonical schema (no syntactic sugar)
  -j, --schema=PATH    save JSON schema to file
  -C, --canonize=PATH  save canonical grammar to file
  -i, --input=PATH     read graphlib JSON file
  -o, --output=PATH    write graphlib JSON file
  -d, --dot=PATH       write graphviz DOT file
  -L, --limit=N        limit number of rule applications
  -S, --stage=N        only run one stage
  -s, --seed=N         seed random number generator
  -q, --quiet          do not print pretty log messages
  -v, --verbose        print MORE pretty log messages
  -h, --help           display this help message