bytev-charts/lib/plugin/three.js/examples/js/shaders/SAOShader.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.SAOShader: 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.");
/**
 * TODO
 */

THREE.SAOShader = {
  defines: {
    "NUM_SAMPLES": 7,
    "NUM_RINGS": 4,
    "NORMAL_TEXTURE": 0,
    "DIFFUSE_TEXTURE": 0,
    "DEPTH_PACKING": 1,
    "PERSPECTIVE_CAMERA": 1
  },
  uniforms: {
    "tDepth": {
      value: null
    },
    "tDiffuse": {
      value: null
    },
    "tNormal": {
      value: null
    },
    "size": {
      value: new THREE.Vector2(512, 512)
    },
    "cameraNear": {
      value: 1
    },
    "cameraFar": {
      value: 100
    },
    "cameraProjectionMatrix": {
      value: new THREE.Matrix4()
    },
    "cameraInverseProjectionMatrix": {
      value: new THREE.Matrix4()
    },
    "scale": {
      value: 1.0
    },
    "intensity": {
      value: 0.1
    },
    "bias": {
      value: 0.5
    },
    "minResolution": {
      value: 0.0
    },
    "kernelRadius": {
      value: 100.0
    },
    "randomSeed": {
      value: 0.0
    }
  },
  vertexShader: ["varying vec2 vUv;", "void main() {", "	vUv = uv;", "	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );", "}"].join("\n"),
  fragmentShader: ["#include <common>", "varying vec2 vUv;", "#if DIFFUSE_TEXTURE == 1", "uniform sampler2D tDiffuse;", "#endif", "uniform sampler2D tDepth;", "#if NORMAL_TEXTURE == 1", "uniform sampler2D tNormal;", "#endif", "uniform float cameraNear;", "uniform float cameraFar;", "uniform mat4 cameraProjectionMatrix;", "uniform mat4 cameraInverseProjectionMatrix;", "uniform float scale;", "uniform float intensity;", "uniform float bias;", "uniform float kernelRadius;", "uniform float minResolution;", "uniform vec2 size;", "uniform float randomSeed;", "// RGBA depth", "#include <packing>", "vec4 getDefaultColor( const in vec2 screenPosition ) {", "	#if DIFFUSE_TEXTURE == 1", "	return texture2D( tDiffuse, vUv );", "	#else", "	return vec4( 1.0 );", "	#endif", "}", "float getDepth( const in vec2 screenPosition ) {", "	#if DEPTH_PACKING == 1", "	return unpackRGBAToDepth( texture2D( tDepth, screenPosition ) );", "	#else", "	return texture2D( tDepth, screenPosition ).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 vec3 viewPosition, const in vec2 screenPosition ) {", "	#if NORMAL_TEXTURE == 1", "	return unpackRGBToNormal( texture2D( tNormal, screenPosition ).xyz );", "	#else", "	return normalize( cross( dFdx( viewPosition ), dFdy( viewPosition ) ) );", "	#endif", "}", "float scaleDividedByCameraFar;", "float minResolutionMultipliedByCameraFar;", "float getOcclusion( const in vec3 centerViewPosition, const in vec3 centerViewNormal, const in vec3 sampleViewPosition ) {", "	vec3 viewDelta = sampleViewPosition - centerViewPosition;", "	float viewDistance = length( viewDelta );", "	float scaledScreenDistance = scaleDividedByCameraFar * viewDistance;", "	return max(0.0, (dot(centerViewNormal, viewDelta) - minResolutionMultipliedByCameraFar) / scaledScreenDistance - bias) / (1.0 + pow2( scaledScreenDistance ) );", "}", "// moving costly divides into consts", "const float ANGLE_STEP = PI2 * float( NUM_RINGS ) / float( NUM_SAMPLES );", "const float INV_NUM_SAMPLES = 1.0 / float( NUM_SAMPLES );", "float getAmbientOcclusion( const in vec3 centerViewPosition ) {", "	// precompute some variables require in getOcclusion.", "	scaleDividedByCameraFar = scale / cameraFar;", "	minResolutionMultipliedByCameraFar = minResolution * cameraFar;", "	vec3 centerViewNormal = getViewNormal( centerViewPosition, vUv );", "	// jsfiddle that shows sample pattern: https://jsfiddle.net/a16ff1p7/", "	float angle = rand( vUv + randomSeed ) * PI2;", "	vec2 radius = vec2( kernelRadius * INV_NUM_SAMPLES ) / size;", "	vec2 radiusStep = radius;", "	float occlusionSum = 0.0;", "	float weightSum = 0.0;", "	for( int i = 0; i < NUM_SAMPLES; i ++ ) {", "		vec2 sampleUv = vUv + vec2( cos( angle ), sin( angle ) ) * radius;", "		radius += radiusStep;", "		angle += ANGLE_STEP;", "		float sampleDepth = getDepth( sampleUv );", "		if( sampleDepth >= ( 1.0 - EPSILON ) ) {", "			continue;", "		}", "		float sampleViewZ = getViewZ( sampleDepth );", "		vec3 sampleViewPosition = getViewPosition( sampleUv, sampleDepth, sampleViewZ );", "		occlusionSum += getOcclusion( centerViewPosition, centerViewNormal, sampleViewPosition );", "		weightSum += 1.0;", "	}", "	if( weightSum == 0.0 ) discard;", "	return occlusionSum * ( intensity / weightSum );", "}", "void main() {", "	float centerDepth = getDepth( vUv );", "	if( centerDepth >= ( 1.0 - EPSILON ) ) {", "		discard;", "	}", "	float centerViewZ = getViewZ( centerDepth );", "	vec3 viewPosition = getViewPosition( vUv, centerDepth, centerViewZ );", "	float ambientOcclusion = getAmbientOcclusion( viewPosition );", "	gl_FragColor = getDefaultColor( vUv );", "	gl_FragColor.xyz *=  1.0 - ambientOcclusion;", "}"].join("\n")
};