glslify-deps

glslify-deps

Walk the dependency graph of a glslify shader.

glslify-deps is responsible for resolving your shader's dependencies and applying their transforms before the actual source modification occurs. You may notice some parallels here with browserify's module-deps package.

While glslify-deps is an "internal" package for glslify, it may be useful to use this package directly in specific cases, e.g. building a file tree server-side but bundling the final shader on the client.

Module API

There is an asynchronous and a synchronous API:

var glslifyDeps = require('glslify-deps')
var glslifyDepsSync = require('glslify-deps/sync')

The asynchronous API is documented below. For every method in the asychronous API, instead of a callback(err, result), the result is available as the return value of the method.

depper = glslifyDeps([options])

Creates a fresh glslify-deps instance. Accepts the following options:

• cwd: the current working directory to resolve relative file paths from.
• readFile: pass in a custom function reading files.
• resolve: pass in a custom function for resolving require calls. It has the same signature as glsl-resolve.
• files: a filename/source object mapping of files to prepopulate the file cache with. Useful for overriding particular file paths manually, most notably the "entry" file.

depper.transform(transform, [options])

Adds a new transform – should be used before calling depper.add.

transform may either be a string (which is resolved like a require call), or a function. More information on transforms can be found below.

depper.add(filename, [callback])

Adds a new file to the dependency graph.

depper.inline(source, basedir, [callback])

Adds a new inline file to the dependency graph, where source is the GLSL source to include and basedir is the directory to pretend it's being created in. A basedir is required to properly resolve requires and transforms, and defaults to process.cwd().

depper.on('file', cb(filename))

Emitted whenever a new file has been included in the dependency graph.

Example Output

[
  {
    "id": 0,
    "deps": { "glsl-random": 1 },
    "file": "index.glsl",
    "source": "precision mediump float;\n#pragma glslify: random = require(glsl-random)\n",
    "entry": true
  },
  {
    "id": 1,
    "deps": {},
    "file": "node_modules/glsl-random/index.glsl",
    "source": "highp float random(vec2 co)\n{\n    highp float a = 12.9898;\n    highp float b = 78.233;\n    highp float c = 43758.5453;\n    highp float dt= dot(co.xy ,vec2(a,b));\n    highp float sn= mod(dt,3.14);\n    return fract(sin(sn) * c);\n}\n\n#pragma glslify: export(random)",
    "entry": false
  }
]

Transform API

The transform API has changed since glslify 1.0 to make it more "vanilla".

With the asynchronous API, transforms have this signature:

module.exports = function(file, source, options, done) {
  done(null, source.toUpperCase())
}

and using the synchronous API, transforms have this signature:

module.exports.sync = function(file, source, options) {
  return source.toUpperCase()
}

For an example that is compatible with both the async and sync APIs, here's glslify-hex rewritten using the new API:

var through = require('through')

var regexLong  = /#([a-f0-9]{2})([a-f0-9]{2})([a-f0-9]{2})([a-f0-9]{2})?/gi
var regexShort = /#([a-f0-9])([a-f0-9])([a-f0-9])([a-f0-9])?/gi

module.exports = transform
module.exports.sync = transform

function transform(filename, src, opts, done) {
  src = src.replace(regexShort, function(whole, r, g, b, a) {
    return !a
      ? '#' + r + r + g + g + b + b
      : '#' + r + r + g + g + b + b + a + a
  }).replace(regexLong, function(whole, r, g, b, a) {
    r = makeFloat(parseInt(r, 16) / 255)
    g = makeFloat(parseInt(g, 16) / 255)
    b = makeFloat(parseInt(b, 16) / 255)
    a = makeFloat(parseInt(a, 16) / 255)

    return isNaN(a)
      ? 'vec3('+[r,g,b].join(',')+')'
      : 'vec4('+[r,g,b,a].join(',')+')'
  })

  if (typeof done === 'function') done(null, src)
  return src
}

function makeFloat(n) {
  return String(n).indexOf('.') === -1
    ? n + '.'
    : n
}

Transforms in package.json

Transforms now support options specified in package.json:

{
  "glslify": {
    "transform": [
       "glslify-hex",
      ["glslify-optimize", { "mangle": true }]
    ]
  }
}