three.js/examples/js/shaders/DepthLimitedBlurShader.js

( function () {

	/**
 * TODO
 */

	var DepthLimitedBlurShader = {
		defines: {
			'KERNEL_RADIUS': 4,
			'DEPTH_PACKING': 1,
			'PERSPECTIVE_CAMERA': 1
		},
		uniforms: {
			'tDiffuse': {
				value: null
			},
			'size': {
				value: new THREE.Vector2( 512, 512 )
			},
			'sampleUvOffsets': {
				value: [ new THREE.Vector2( 0, 0 ) ]
			},
			'sampleWeights': {
				value: [ 1.0 ]
			},
			'tDepth': {
				value: null
			},
			'cameraNear': {
				value: 10
			},
			'cameraFar': {
				value: 1000
			},
			'depthCutoff': {
				value: 10
			}
		},
		vertexShader: [ '#include <common>', 'uniform vec2 size;', 'varying vec2 vUv;', 'varying vec2 vInvSize;', 'void main() {', '	vUv = uv;', '	vInvSize = 1.0 / size;', '	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );', '}' ].join( '\n' ),
		fragmentShader: [ '#include <common>', '#include <packing>', 'uniform sampler2D tDiffuse;', 'uniform sampler2D tDepth;', 'uniform float cameraNear;', 'uniform float cameraFar;', 'uniform float depthCutoff;', 'uniform vec2 sampleUvOffsets[ KERNEL_RADIUS + 1 ];', 'uniform float sampleWeights[ KERNEL_RADIUS + 1 ];', 'varying vec2 vUv;', 'varying vec2 vInvSize;', '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', '}', 'void main() {', '	float depth = getDepth( vUv );', '	if( depth >= ( 1.0 - EPSILON ) ) {', '		discard;', '	}', '	float centerViewZ = -getViewZ( depth );', '	bool rBreak = false, lBreak = false;', '	float weightSum = sampleWeights[0];', '	vec4 diffuseSum = texture2D( tDiffuse, vUv ) * weightSum;', '	for( int i = 1; i <= KERNEL_RADIUS; i ++ ) {', '		float sampleWeight = sampleWeights[i];', '		vec2 sampleUvOffset = sampleUvOffsets[i] * vInvSize;', '		vec2 sampleUv = vUv + sampleUvOffset;', '		float viewZ = -getViewZ( getDepth( sampleUv ) );', '		if( abs( viewZ - centerViewZ ) > depthCutoff ) rBreak = true;', '		if( ! rBreak ) {', '			diffuseSum += texture2D( tDiffuse, sampleUv ) * sampleWeight;', '			weightSum += sampleWeight;', '		}', '		sampleUv = vUv - sampleUvOffset;', '		viewZ = -getViewZ( getDepth( sampleUv ) );', '		if( abs( viewZ - centerViewZ ) > depthCutoff ) lBreak = true;', '		if( ! lBreak ) {', '			diffuseSum += texture2D( tDiffuse, sampleUv ) * sampleWeight;', '			weightSum += sampleWeight;', '		}', '	}', '	gl_FragColor = diffuseSum / weightSum;', '}' ].join( '\n' )
	};
	var BlurShaderUtils = {
		createSampleWeights: function ( kernelRadius, stdDev ) {

			var gaussian = function ( x, stdDev ) {

				return Math.exp( - ( x * x ) / ( 2.0 * ( stdDev * stdDev ) ) ) / ( Math.sqrt( 2.0 * Math.PI ) * stdDev );

			};

			var weights = [];

			for ( var i = 0; i <= kernelRadius; i ++ ) {

				weights.push( gaussian( i, stdDev ) );

			}

			return weights;

		},
		createSampleOffsets: function ( kernelRadius, uvIncrement ) {

			var offsets = [];

			for ( var i = 0; i <= kernelRadius; i ++ ) {

				offsets.push( uvIncrement.clone().multiplyScalar( i ) );

			}

			return offsets;

		},
		configure: function ( material, kernelRadius, stdDev, uvIncrement ) {

			material.defines[ 'KERNEL_RADIUS' ] = kernelRadius;
			material.uniforms[ 'sampleUvOffsets' ].value = BlurShaderUtils.createSampleOffsets( kernelRadius, uvIncrement );
			material.uniforms[ 'sampleWeights' ].value = BlurShaderUtils.createSampleWeights( kernelRadius, stdDev );
			material.needsUpdate = true;

		}
	};

	THREE.BlurShaderUtils = BlurShaderUtils;
	THREE.DepthLimitedBlurShader = DepthLimitedBlurShader;

} )();