three-shaders/shaders/LuminosityShader.js

three-shaders - a library of shaders included with Three.js library

/**
 * @author alteredq / http://alteredqualia.com/
 *
 * Luminosity
 * http://en.wikipedia.org/wiki/Luminosity
 */

function LuminosityShader() {

	return {

	uniforms: {

		tDiffuse: { value: null }

	},

	vertexShader: `

		varying vec2 vUv;

		void main() {

			vUv = uv;

			gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );

		}

	`,

	fragmentShader: `

		uniform sampler2D tDiffuse;

		varying vec2 vUv;

		void main() {

			vec4 texel = texture2D( tDiffuse, vUv );

			vec3 luma = vec3( 0.299, 0.587, 0.114 );

			float v = dot( texel.xyz, luma );

			gl_FragColor = vec4( v, v, v, texel.w );

		}

	`
	}

};

module.exports = LuminosityShader;