material.js

const Signal = require('signals')
const { mat3, mat2x3 } = require('pex-math')

let MaterialID = 0

const tempMat2x3 = mat2x3.create()

const MATERIAL_MAPS = [
  'baseColorMap',
  'emissiveColorMap',
  'matallicMap',
  'roughnessMap',
  'metallicRoughnessMap',
  'normalMap',
  'clearCoatNormalMap',
  'occlusionMap',
  'diffuseMap',
  'specularGlossinessMap'
]

const PIPELINE_PROPS = [
  'depthTest',
  'depthWrite',
  'depthFunc',
  'blend',
  'blendSrcRGBFactor',
  'blendSrcAlphaFactor',
  'blendDstRGBFactor',
  'blendDstAlphaFactor',
  'cullFace',
  'cullFaceMode'
]

function Material(opts) {
  this.type = 'Material'
  this.id = 'Material_' + MaterialID++
  this.enabled = true
  this.changed = new Signal()

  this._uniforms = {}

  const ctx = opts.ctx

  this.baseColor = [1, 1, 1, 1]
  this.baseColorMap = null

  this.useSpecularGlossinessWorkflow =
    opts.useSpecularGlossinessWorkflow || false
  this.unlit = opts.unlit || false
  if (opts.useSpecularGlossinessWorkflow) {
    // Specular Glossiness workflow
    this.diffuse = [1, 1, 1, 1]
    this.diffuseMap = null
    this.specular = [1, 1, 1]
    this.glossiness = 1
    this.specularGlossinessMap = null
  } else if (!this.unlit) {
    // Metallic Roughness workflow
    this.metallic = 1
    this.matallicMap = null
    this.roughness = 1
    this.roughnessMap = null
    this.metallicRoughnessMap = null
  }

  this.normalMap = null
  this.normalScale = 1

  this.displacementMap = null
  this.displacement = 0

  this.emissiveColor = null
  this.emissiveIntensity = 1
  this.emissiveColorMap = null

  this.occlusionMap = null

  this.reflectance = 0.5
  this.clearCoat = null
  this.clearCoatRoughness = null
  this.clearCoatNormalMap = null
  this.clearCoatNormalMapScale = 1 //TODO: what's clearCoatNormalMapScale

  this.alphaMap = null
  this.alphaTest = undefined

  // pipeline props
  this.depthTest = true
  this.depthWrite = true
  this.depthFunc = ctx.DepthFunc.LessEqual
  this.blend = false
  this.blendSrcRGBFactor = ctx.BlendFactor.One
  this.blendSrcAlphaFactor = ctx.BlendFactor.One
  this.blendDstRGBFactor = ctx.BlendFactor.One
  this.blendDstAlphaFactor = ctx.BlendFactor.One
  this.cullFace = true
  this.cullFaceMode = ctx.Face.Back

  this.pointSize = 1

  this.castShadows = false
  this.receiveShadows = false

  this.needsPipelineUpdate = false

  this.set(opts)
}

Material.prototype.init = function(entity) {
  this.entity = entity
}

Material.prototype.set = function(opts) {
  Object.assign(this, opts)

  const optsKeys = Object.keys(opts)

  const mapKeys = optsKeys.filter((opt) => MATERIAL_MAPS.includes(opt))
  if (mapKeys.length) {
    for (let i = 0; i < mapKeys.length; i++) {
      const map = this[mapKeys[i]]
      if (map && map.texture) {
        mat2x3.identity(tempMat2x3)
        mat2x3.translate(tempMat2x3, map.offset || [0, 0])
        mat2x3.rotate(tempMat2x3, -map.rotation || 0)
        mat2x3.scale(tempMat2x3, map.scale || [1, 1])

        map.texCoordTransformMatrix = mat3.fromMat2x3(
          map.texCoordTransformMatrix
            ? mat3.identity(map.texCoordTransformMatrix)
            : mat3.create(),
          tempMat2x3
        )
      }
    }
  }

  for (let pipelineProp of PIPELINE_PROPS) {
    if (opts[pipelineProp] !== undefined) {
      this.needsPipelineUpdate = true
    }
  }

  optsKeys.forEach((prop) => this.changed.dispatch(prop))
}

module.exports = function(opts) {
  return new Material(opts)
}