File size: 3,707 Bytes
a28eca3
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
import {
	Vector2
} from 'three';

/**
 * TODO
 */

const DepthLimitedBlurShader = {

	name: 'DepthLimitedBlurShader',

	defines: {
		'KERNEL_RADIUS': 4,
		'DEPTH_PACKING': 1,
		'PERSPECTIVE_CAMERA': 1
	},

	uniforms: {
		'tDiffuse': { value: null },
		'size': { value: new Vector2( 512, 512 ) },
		'sampleUvOffsets': { value: [ new Vector2( 0, 0 ) ] },
		'sampleWeights': { value: [ 1.0 ] },
		'tDepth': { value: null },
		'cameraNear': { value: 10 },
		'cameraFar': { value: 1000 },
		'depthCutoff': { value: 10 },
	},

	vertexShader: /* glsl */`

		#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 );
		}`,

	fragmentShader: /* glsl */`

		#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;
		}`

};

const BlurShaderUtils = {

	createSampleWeights: function ( kernelRadius, stdDev ) {

		const weights = [];

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

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

		}

		return weights;

	},

	createSampleOffsets: function ( kernelRadius, uvIncrement ) {

		const offsets = [];

		for ( let 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;

	}

};

function gaussian( x, stdDev ) {

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

}

export { DepthLimitedBlurShader, BlurShaderUtils };