/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

import random from "../random/random.ts";

export default class shaders {
  static get fragment1() {
    return [
      [
        "#ifdef GL_ES",
        "precision mediump float;",
        "#endif",
        "varying vec4 vColor;",
        "void main() {",
        "gl_FragColor=vColor;",
        "}"
      ],
      [
        "varying highp vec2 vTextureCoord;",
        "varying highp vec3 vLighting;",
        "uniform sampler2D uSampler;",
        "void main(void) {",
        "highp vec4 texelColor = texture2D(uSampler, vec2(vTextureCoord.s, vTextureCoord.t));",
        "gl_FragColor = vec4(texelColor.rgb * vLighting, texelColor.a);",
        "}"
      ]
    ];
  }

  static get vertex1() {
    return [
      [
        "attribute vec4 aVertex;",
        "attribute vec4 aColor;",
        "varying vec4 vColor;",
        "void main(){",
        "vColor=aColor;",
        "gl_Position=aVertex;",
        "}"
      ],
      [
        "attribute highp vec3 aVertexNormal;",
        "attribute highp vec3 aVertexPosition;",
        "attribute highp vec2 aTextureCoord;",
        "uniform highp mat4 uNormalMatrix;",
        "uniform highp mat4 uMVMatrix;",
        "uniform highp mat4 uPMatrix;",
        "varying highp vec2 vTextureCoord;",
        "varying highp vec3 vLighting;",
        "void main(void) {",
        "gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0);",
        "vTextureCoord = aTextureCoord;",
        "highp vec3 ambientLight = vec3(0.6, 0.6, 0.6);",
        "highp vec3 directionalLightColor = vec3(0.5, 0.5, 0.75);",
        "highp vec3 directionalVector = vec3(0.85, 0.8, 0.75);",
        "highp vec4 transformedNormal = uNormalMatrix * vec4(aVertexNormal, 1.0);",
        "highp float directional = max(dot(transformedNormal.xyz, directionalVector), 0.0);",
        "vLighting = ambientLight + (directionalLightColor * directional);",
        "}"
      ]
    ];
  }

  static get fragment2() {
    return [
      [
        "varying highp vec2 vTextureCoord;",
        "varying highp vec3 vLighting;",
        "uniform sampler2D uSampler;",
        "void main(void) {",
        "highp vec4 texelColor = texture2D(uSampler, vec2(vTextureCoord.s, vTextureCoord.t));",
        "gl_FragColor = vec4(texelColor.rgb * vLighting, texelColor.a);",
        "}"
      ],
      [
        "#version proto-200",
        "uniform sampler2D albedoMap;",
        "uniform sampler2D normalMap;",
        "varying vec3 varyingTangent;",
        "varying vec3 varyingBitangent;",
        "varying vec3 varyingNormal;",
        "varying vec2 varyingUV;",
        "void main(void) {",
        "vec3 albedo=texture2D(albedoMap,varyingUV).rgb;",
        "vec3 normal=texture2D(normalMap,varyingUV).rgb*2.0-1.0;",
        "float specularFactor=pow((albedo.r+albedo.g+albedo.b)*0.33,2.0);",
        "float specularHardness=2.0;",
        "vec3 spaceNormal=varyingTangent*normal.x+varyingBitangent*normal.y+varyingNormal*normal.z;",
        "gl_FragData[0]=vec4(albedo,1.0);",
        "gl_FragData[1]=vec4(spaceNormal*0.5 +0.5,1.0);",
        "gl_FragData[2]=vec4(specularFactor,specularHardness*0.1,0.0,1.0);",
        "}"
      ]
    ];
  }

  static get vertex2() {
    return [
      [
        "attribute highp vec3 aVertexNormal;",
        "attribute highp vec3 aVertexPosition;",
        "attribute highp vec2 aTextureCoord;",
        "uniform highp mat4 uNormalMatrix;",
        "uniform highp mat4 uMVMatrix;",
        "uniform highp mat4 uPMatrix;",
        "varying highp vec2 vTextureCoord;",
        "varying highp vec3 vLighting;",
        "void main(void) {",
        "gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0);",
        "vTextureCoord = aTextureCoord;",
        "highp vec3 ambientLight = vec3(0.6, 0.6, 0.6);",
        "highp vec3 directionalLightColor = vec3(0.5, 0.5, 0.75);",
        "highp vec3 directionalVector = vec3(0.85, 0.8, 0.75);",
        "highp vec4 transformedNormal = uNormalMatrix * vec4(aVertexNormal, 1.0);",
        "highp float directional = max(dot(transformedNormal.xyz, directionalVector), 0.0);",
        "vLighting = ambientLight + (directionalLightColor * directional);",
        "}"
      ],
      [
        "#version proto-200",
        "attribute vec3 vertexPosition;",
        "attribute vec3 vertexTangent;",
        "attribute vec3 vertexBitangent;",
        "attribute vec3 vertexNormal;",
        "attribute vec2 vertexUV;",
        "uniform mat4 modelMatrix;",
        "uniform mat4 viewMatrix;",
        "varying vec3 varyingTangent;",
        "varying vec3 varyingBitangent;",
        "varying vec3 varyingNormal;",
        "varying vec2 varyingUV;",
        "void main(void){",
        "gl_Position=viewMatrix*(modelMatrix*vec4(vertexPosition,1.0));",
        "gl_Position.xy=gl_Position.xy*0.5+(float(gl_InstanceID)-0.5);",
        "varyingTangent=(modelMatrix*vec4(vertexTangent,0.0)).xyz;",
        "varyingBitangent=(modelMatrix*vec4(vertexBitangent,0.0)).xyz;",
        "varyingNormal=(modelMatrix*vec4(vertexNormal,0.0)).xyz;",
        "varyingUV = vertexUV;",
        "}"
      ]
    ];
  }

  static shaderPair(v, f) {
    let i = random.number(v.length);
    return {
      vertex: v[i].join(" "),
      fragment: f[i].join(" ")
    };
  }
}