import { Shader } from 'three' ; author aeroheim / http://aeroheim.moe/
  const VignetteBlendShader = { uniforms : { tDiffuse1 : { value : null } , tDiffuse2 : { value : null } , size : { value : 1.0 } , } , vertexShader : `

    varying vec2 vUv;

    void main() {
      vUv = uv;
      gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
    }

  ` , fragmentShader : `

    uniform sampler2D tDiffuse1;
    uniform sampler2D tDiffuse2;
    uniform float size;
    varying vec2 vUv;

    void main() {
      vec2 uv = (vUv - vec2(0.5));
      float mixRatio = smoothstep(0.0, 1.0, min(dot(uv, uv) * size, 1.0));
      gl_FragColor = mix(texture2D(tDiffuse1, vUv), texture2D(tDiffuse2, vUv), mixRatio);
    }

  ` , } ; export { VignetteBlendShader , } ; export default VignetteBlendShader ;