three.js/examples/js/shaders/DOFMipMapShader.js

( function () {

	/**
 * Depth-of-field shader using mipmaps
 * - from Matt Handley @applmak
 * - requires power-of-2 sized render target with enabled mipmaps
 */
	var DOFMipMapShader = {
		uniforms: {
			'tColor': {
				value: null
			},
			'tDepth': {
				value: null
			},
			'focus': {
				value: 1.0
			},
			'maxblur': {
				value: 1.0
			}
		},
		vertexShader: [ 'varying vec2 vUv;', 'void main() {', '	vUv = uv;', '	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );', '}' ].join( '\n' ),
		fragmentShader: [ 'uniform float focus;', 'uniform float maxblur;', 'uniform sampler2D tColor;', 'uniform sampler2D tDepth;', 'varying vec2 vUv;', 'void main() {', '	vec4 depth = texture2D( tDepth, vUv );', '	float factor = depth.x - focus;', '	vec4 col = texture2D( tColor, vUv, 2.0 * maxblur * abs( focus - depth.x ) );', '	gl_FragColor = col;', '	gl_FragColor.a = 1.0;', '}' ].join( '\n' )
	};

	THREE.DOFMipMapShader = DOFMipMapShader;

} )();