https://github.com/WWBN/AVideo/issues/8713

node_modules/three/examples/js/shaders/ConvolutionShader.js

@@ -0,0 +1,99 @@
+/**
+ * Convolution shader
+ * ported from o3d sample to WebGL / GLSL
+ * http://o3d.googlecode.com/svn/trunk/samples/convolution.html
+ */
+
+THREE.ConvolutionShader = {
+
+	defines: {
+
+		'KERNEL_SIZE_FLOAT': '25.0',
+		'KERNEL_SIZE_INT': '25'
+
+	},
+
+	uniforms: {
+
+		'tDiffuse': { value: null },
+		'uImageIncrement': { value: new THREE.Vector2( 0.001953125, 0.0 ) },
+		'cKernel': { value: [] }
+
+	},
+
+	vertexShader: [
+
+		'uniform vec2 uImageIncrement;',
+
+		'varying vec2 vUv;',
+
+		'void main() {',
+
+		'	vUv = uv - ( ( KERNEL_SIZE_FLOAT - 1.0 ) / 2.0 ) * uImageIncrement;',
+		'	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );',
+
+		'}'
+
+	].join( '\n' ),
+
+	fragmentShader: [
+
+		'uniform float cKernel[ KERNEL_SIZE_INT ];',
+
+		'uniform sampler2D tDiffuse;',
+		'uniform vec2 uImageIncrement;',
+
+		'varying vec2 vUv;',
+
+		'void main() {',
+
+		'	vec2 imageCoord = vUv;',
+		'	vec4 sum = vec4( 0.0, 0.0, 0.0, 0.0 );',
+
+		'	for( int i = 0; i < KERNEL_SIZE_INT; i ++ ) {',
+
+		'		sum += texture2D( tDiffuse, imageCoord ) * cKernel[ i ];',
+		'		imageCoord += uImageIncrement;',
+
+		'	}',
+
+		'	gl_FragColor = sum;',
+
+		'}'
+
+
+	].join( '\n' ),
+
+	buildKernel: function ( sigma ) {
+
+		// We lop off the sqrt(2 * pi) * sigma term, since we're going to normalize anyway.
+
+		function gauss( x, sigma ) {
+
+			return Math.exp( - ( x * x ) / ( 2.0 * sigma * sigma ) );
+
+		}
+
+		var i, values, sum, halfWidth, kMaxKernelSize = 25, kernelSize = 2 * Math.ceil( sigma * 3.0 ) + 1;
+
+		if ( kernelSize > kMaxKernelSize ) kernelSize = kMaxKernelSize;
+		halfWidth = ( kernelSize - 1 ) * 0.5;
+
+		values = new Array( kernelSize );
+		sum = 0.0;
+		for ( i = 0; i < kernelSize; ++ i ) {
+
+			values[ i ] = gauss( i - halfWidth, sigma );
+			sum += values[ i ];
+
+		}
+
+		// normalize the kernel
+
+		for ( i = 0; i < kernelSize; ++ i ) values[ i ] /= sum;
+
+		return values;
+
+	}
+
+};