text: import {
  	Vector2
  } from '../../three.module.js';
  
  /**
   * Dot screen shader
   * based on glfx.js sepia shader
   * https://github.com/evanw/glfx.js
   */
  
  const DotScreenShader = {
  
  	uniforms: {
  
  		'tDiffuse': { value: null },
  		'tSize': { value: new Vector2( 256, 256 ) },
  		'center': { value: new Vector2( 0.5, 0.5 ) },
  		'angle': { value: 1.57 },
  		'scale': { value: 1.0 }
  
  	},
  
  	vertexShader: /* glsl */`
  
  		varying vec2 vUv;
  
  		void main() {
  
  			vUv = uv;
  			gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
  
  		}`,
  
  	fragmentShader: /* glsl */`
  
  		uniform vec2 center;
  		uniform float angle;
  		uniform float scale;
  		uniform vec2 tSize;
  
  		uniform sampler2D tDiffuse;
  
  		varying vec2 vUv;
  
  		float pattern() {
  
  			float s = sin( angle ), c = cos( angle );
  
  			vec2 tex = vUv * tSize - center;
  			vec2 point = vec2( c * tex.x - s * tex.y, s * tex.x + c * tex.y ) * scale;
  
  			return ( sin( point.x ) * sin( point.y ) ) * 4.0;
  
  		}
  
  		void main() {
  
  			vec4 color = texture2D( tDiffuse, vUv );
  
  			float average = ( color.r + color.g + color.b ) / 3.0;
  
  			gl_FragColor = vec4( vec3( average * 10.0 - 5.0 + pattern() ), color.a );
  
  		}`
  
  };
  
  export { DotScreenShader };
  