src/shader/shader-utils.js

/**
 * @file Shader Utils
 * @author Alexander Rose <alexander.rose@weirdbyte.de>
 * @private
 */

import { ShaderChunk } from '../../lib/three.es6.js'

import './chunk/dull_interior_fragment.glsl'
import './chunk/fog_fragment.glsl'
import './chunk/matrix_scale.glsl'
import './chunk/nearclip_vertex.glsl'
import './chunk/nearclip_fragment.glsl'
import './chunk/opaque_back_fragment.glsl'
import './chunk/radiusclip_vertex.glsl'
import './chunk/radiusclip_fragment.glsl'
import './chunk/unpack_color.glsl'

import { ShaderRegistry } from '../globals.js'

function getDefines (defines) {
  if (defines === undefined) return ''

  var lines = []

  for (var name in defines) {
    var value = defines[ name ]

    if (value === false) continue

    lines.push('#define ' + name + ' ' + value)
  }

  return lines.join('\n') + '\n'
}

var reInclude = /^(?!\/\/)\s*#include\s+(\S+)/gmi
var shaderCache = {}

function getShader (name, defines) {
  defines = defines || {}

  var hash = name + '|'
  for (var key in defines) {
    hash += key + ':' + defines[ key ]
  }

  if (!shaderCache[ hash ]) {
    var definesText = getDefines(defines)

    var shaderText = ShaderRegistry.get('shader/' + name)
    if (!shaderText) {
      throw new Error("empty shader, '" + name + "'")
    }
    shaderText = shaderText.replace(reInclude, function (match, p1) {
      var path = 'shader/chunk/' + p1 + '.glsl'
      var chunk = ShaderRegistry.get(path) || ShaderChunk[ p1 ]

      return chunk || ''
    })

    shaderCache[ hash ] = definesText + shaderText
  }

  return shaderCache[ hash ]
}

export {
  getShader
}