bytev-charts/lib/plugin/three.js/examples/js/shaders/SSAOShader.js

基于echarts和JavaScript及ES6封装的一个可以直接调用的图表组件库，内置主题设计，简单快捷，且支持用户自定义配置； npm 安装方式: npm install bytev-charts 若启动提示还需额外install插件,则运行 npm install @babel/runtime-corejs2 即可;

import "core-js/modules/es.array.join.js";
console.warn("THREE.SSAOShader: As part of the transition to ES6 Modules, the files in 'examples/js' were deprecated in May 2020 (r117) and will be deleted in December 2020 (r124). You can find more information about developing using ES6 Modules in https://threejs.org/docs/#manual/en/introduction/Installation.");
/**
 * References:
 * http://john-chapman-graphics.blogspot.com/2013/01/ssao-tutorial.html
 * https://learnopengl.com/Advanced-Lighting/SSAO
 * https://github.com/McNopper/OpenGL/blob/master/Example28/shader/ssao.frag.glsl
 */

THREE.SSAOShader = {
  defines: {
    "PERSPECTIVE_CAMERA": 1,
    "KERNEL_SIZE": 32
  },
  uniforms: {
    "tDiffuse": {
      value: null
    },
    "tNormal": {
      value: null
    },
    "tDepth": {
      value: null
    },
    "tNoise": {
      value: null
    },
    "kernel": {
      value: null
    },
    "cameraNear": {
      value: null
    },
    "cameraFar": {
      value: null
    },
    "resolution": {
      value: new THREE.Vector2()
    },
    "cameraProjectionMatrix": {
      value: new THREE.Matrix4()
    },
    "cameraInverseProjectionMatrix": {
      value: new THREE.Matrix4()
    },
    "kernelRadius": {
      value: 8
    },
    "minDistance": {
      value: 0.005
    },
    "maxDistance": {
      value: 0.05
    }
  },
  vertexShader: ["varying vec2 vUv;", "void main() {", "	vUv = uv;", "	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );", "}"].join("\n"),
  fragmentShader: ["uniform sampler2D tDiffuse;", "uniform sampler2D tNormal;", "uniform sampler2D tDepth;", "uniform sampler2D tNoise;", "uniform vec3 kernel[ KERNEL_SIZE ];", "uniform vec2 resolution;", "uniform float cameraNear;", "uniform float cameraFar;", "uniform mat4 cameraProjectionMatrix;", "uniform mat4 cameraInverseProjectionMatrix;", "uniform float kernelRadius;", "uniform float minDistance;", // avoid artifacts caused by neighbour fragments with minimal depth difference
  "uniform float maxDistance;", // avoid the influence of fragments which are too far away
  "varying vec2 vUv;", "#include <packing>", "float getDepth( const in vec2 screenPosition ) {", "	return texture2D( tDepth, screenPosition ).x;", "}", "float getLinearDepth( const in vec2 screenPosition ) {", "	#if PERSPECTIVE_CAMERA == 1", "		float fragCoordZ = texture2D( tDepth, screenPosition ).x;", "		float viewZ = perspectiveDepthToViewZ( fragCoordZ, cameraNear, cameraFar );", "		return viewZToOrthographicDepth( viewZ, cameraNear, cameraFar );", "	#else", "		return texture2D( depthSampler, coord ).x;", "	#endif", "}", "float getViewZ( const in float depth ) {", "	#if PERSPECTIVE_CAMERA == 1", "		return perspectiveDepthToViewZ( depth, cameraNear, cameraFar );", "	#else", "		return orthographicDepthToViewZ( depth, cameraNear, cameraFar );", "	#endif", "}", "vec3 getViewPosition( const in vec2 screenPosition, const in float depth, const in float viewZ ) {", "	float clipW = cameraProjectionMatrix[2][3] * viewZ + cameraProjectionMatrix[3][3];", "	vec4 clipPosition = vec4( ( vec3( screenPosition, depth ) - 0.5 ) * 2.0, 1.0 );", "	clipPosition *= clipW; // unprojection.", "	return ( cameraInverseProjectionMatrix * clipPosition ).xyz;", "}", "vec3 getViewNormal( const in vec2 screenPosition ) {", "	return unpackRGBToNormal( texture2D( tNormal, screenPosition ).xyz );", "}", "void main() {", "	float depth = getDepth( vUv );", "	float viewZ = getViewZ( depth );", "	vec3 viewPosition = getViewPosition( vUv, depth, viewZ );", "	vec3 viewNormal = getViewNormal( vUv );", " vec2 noiseScale = vec2( resolution.x / 4.0, resolution.y / 4.0 );", "	vec3 random = texture2D( tNoise, vUv * noiseScale ).xyz;", // compute matrix used to reorient a kernel vector
  "	vec3 tangent = normalize( random - viewNormal * dot( random, viewNormal ) );", "	vec3 bitangent = cross( viewNormal, tangent );", "	mat3 kernelMatrix = mat3( tangent, bitangent, viewNormal );", " float occlusion = 0.0;", " for ( int i = 0; i < KERNEL_SIZE; i ++ ) {", "		vec3 sampleVector = kernelMatrix * kernel[ i ];", // reorient sample vector in view space
  "		vec3 samplePoint = viewPosition + ( sampleVector * kernelRadius );", // calculate sample point
  "		vec4 samplePointNDC = cameraProjectionMatrix * vec4( samplePoint, 1.0 );", // project point and calculate NDC
  "		samplePointNDC /= samplePointNDC.w;", "		vec2 samplePointUv = samplePointNDC.xy * 0.5 + 0.5;", // compute uv coordinates
  "		float realDepth = getLinearDepth( samplePointUv );", // get linear depth from depth texture
  "		float sampleDepth = viewZToOrthographicDepth( samplePoint.z, cameraNear, cameraFar );", // compute linear depth of the sample view Z value
  "		float delta = sampleDepth - realDepth;", "		if ( delta > minDistance && delta < maxDistance ) {", // if fragment is before sample point, increase occlusion
  "			occlusion += 1.0;", "		}", "	}", "	occlusion = clamp( occlusion / float( KERNEL_SIZE ), 0.0, 1.0 );", "	gl_FragColor = vec4( vec3( 1.0 - occlusion ), 1.0 );", "}"].join("\n")
};
THREE.SSAODepthShader = {
  defines: {
    "PERSPECTIVE_CAMERA": 1
  },
  uniforms: {
    "tDepth": {
      value: null
    },
    "cameraNear": {
      value: null
    },
    "cameraFar": {
      value: null
    }
  },
  vertexShader: ["varying vec2 vUv;", "void main() {", "	vUv = uv;", "	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );", "}"].join("\n"),
  fragmentShader: ["uniform sampler2D tDepth;", "uniform float cameraNear;", "uniform float cameraFar;", "varying vec2 vUv;", "#include <packing>", "float getLinearDepth( const in vec2 screenPosition ) {", "	#if PERSPECTIVE_CAMERA == 1", "		float fragCoordZ = texture2D( tDepth, screenPosition ).x;", "		float viewZ = perspectiveDepthToViewZ( fragCoordZ, cameraNear, cameraFar );", "		return viewZToOrthographicDepth( viewZ, cameraNear, cameraFar );", "	#else", "		return texture2D( depthSampler, coord ).x;", "	#endif", "}", "void main() {", "	float depth = getLinearDepth( vUv );", "	gl_FragColor = vec4( vec3( 1.0 - depth ), 1.0 );", "}"].join("\n")
};
THREE.SSAOBlurShader = {
  uniforms: {
    "tDiffuse": {
      value: null
    },
    "resolution": {
      value: new THREE.Vector2()
    }
  },
  vertexShader: ["varying vec2 vUv;", "void main() {", "	vUv = uv;", "	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );", "}"].join("\n"),
  fragmentShader: ["uniform sampler2D tDiffuse;", "uniform vec2 resolution;", "varying vec2 vUv;", "void main() {", "	vec2 texelSize = ( 1.0 / resolution );", "	float result = 0.0;", "	for ( int i = - 2; i <= 2; i ++ ) {", "		for ( int j = - 2; j <= 2; j ++ ) {", "			vec2 offset = ( vec2( float( i ), float( j ) ) ) * texelSize;", "			result += texture2D( tDiffuse, vUv + offset ).r;", "		}", "	}", "	gl_FragColor = vec4( vec3( result / ( 5.0 * 5.0 ) ), 1.0 );", "}"].join("\n")
};