text: import {
    MeshBasicMaterial,
    Vector2,
    Color,
  } from "../third_party/three.module.js";
  
  class Material extends MeshBasicMaterial {
    constructor(options) {
      super(options);
  
      this.params = {
        scale: 0.25,
        offset: 0.25,
        width: 0.5,
      };
  
      this.uniforms = {
        resolution: { value: new Vector2(1, 1) },
        paperTexture: { value: null },
        scale: { value: this.params.scale },
        offset: { value: this.params.offset },
        width: { value: this.params.width },
      };
  
      this.onBeforeCompile = (shader, renderer) => {
        for (const uniformName of Object.keys(this.uniforms)) {
          shader.uniforms[uniformName] = this.uniforms[uniformName];
        }
  
        shader.vertexShader = shader.vertexShader.replace(
          `#include <common>`,
          `#include <common>
          out vec2 vCoords;
          out vec3 vPosition;
          out vec4 vWorldPosition;`
        );
        shader.vertexShader = shader.vertexShader.replace(
          `#include <uv_vertex>`,
          `#include <uv_vertex>
          vCoords = uv;
          vPosition = position;
          vWorldPosition = modelMatrix * vec4(position, 1.);// + vec4(normal.xyz, 0.);`
        );
  
        shader.fragmentShader = shader.fragmentShader.replace(
          `#include <common>`,
          `#include <common>
          uniform vec2 resolution;
          uniform sampler2D paperTexture;
          uniform float scale;
          uniform float offset;
          uniform float width;
  
          in vec2 vCoords;
          in vec3 vPosition;
          in vec4 vWorldPosition;
          #define TAU 6.28318530718
  
          //	Classic Perlin 3D Noise 
          //	by Stefan Gustavson
          //
          vec4 permute(vec4 x){return mod(((x*34.0)+1.0)*x, 289.0);}
          vec4 taylorInvSqrt(vec4 r){return 1.79284291400159 - 0.85373472095314 * r;}
          vec3 fade(vec3 t) {return t*t*t*(t*(t*6.0-15.0)+10.0);}
          
          float cnoise(vec3 P){
            vec3 Pi0 = floor(P); // Integer part for indexing
            vec3 Pi1 = Pi0 + vec3(1.0); // Integer part + 1
            Pi0 = mod(Pi0, 289.0);
            Pi1 = mod(Pi1, 289.0);
            vec3 Pf0 = fract(P); // Fractional part for interpolation
            vec3 Pf1 = Pf0 - vec3(1.0); // Fractional part - 1.0
            vec4 ix = vec4(Pi0.x, Pi1.x, Pi0.x, Pi1.x);
            vec4 iy = vec4(Pi0.yy, Pi1.yy);
            vec4 iz0 = Pi0.zzzz;
            vec4 iz1 = Pi1.zzzz;
          
            vec4 ixy = permute(permute(ix) + iy);
            vec4 ixy0 = permute(ixy + iz0);
            vec4 ixy1 = permute(ixy + iz1);
          
            vec4 gx0 = ixy0 / 7.0;
            vec4 gy0 = fract(floor(gx0) / 7.0) - 0.5;
            gx0 = fract(gx0);
            vec4 gz0 = vec4(0.5) - abs(gx0) - abs(gy0);
            vec4 sz0 = step(gz0, vec4(0.0));
            gx0 -= sz0 * (step(0.0, gx0) - 0.5);
            gy0 -= sz0 * (step(0.0, gy0) - 0.5);
          
            vec4 gx1 = ixy1 / 7.0;
            vec4 gy1 = fract(floor(gx1) / 7.0) - 0.5;
            gx1 = fract(gx1);
            vec4 gz1 = vec4(0.5) - abs(gx1) - abs(gy1);
            vec4 sz1 = step(gz1, vec4(0.0));
            gx1 -= sz1 * (step(0.0, gx1) - 0.5);
            gy1 -= sz1 * (step(0.0, gy1) - 0.5);
          
            vec3 g000 = vec3(gx0.x,gy0.x,gz0.x);
            vec3 g100 = vec3(gx0.y,gy0.y,gz0.y);
            vec3 g010 = vec3(gx0.z,gy0.z,gz0.z);
            vec3 g110 = vec3(gx0.w,gy0.w,gz0.w);
            vec3 g001 = vec3(gx1.x,gy1.x,gz1.x);
            vec3 g101 = vec3(gx1.y,gy1.y,gz1.y);
            vec3 g011 = vec3(gx1.z,gy1.z,gz1.z);
            vec3 g111 = vec3(gx1.w,gy1.w,gz1.w);
          
            vec4 norm0 = taylorInvSqrt(vec4(dot(g000, g000), dot(g010, g010), dot(g100, g100), dot(g110, g110)));
            g000 *= norm0.x;
            g010 *= norm0.y;
            g100 *= norm0.z;
            g110 *= norm0.w;
            vec4 norm1 = taylorInvSqrt(vec4(dot(g001, g001), dot(g011, g011), dot(g101, g101), dot(g111, g111)));
            g001 *= norm1.x;
            g011 *= norm1.y;
            g101 *= norm1.z;
            g111 *= norm1.w;
          
            float n000 = dot(g000, Pf0);
            float n100 = dot(g100, vec3(Pf1.x, Pf0.yz));
            float n010 = dot(g010, vec3(Pf0.x, Pf1.y, Pf0.z));
            float n110 = dot(g110, vec3(Pf1.xy, Pf0.z));
            float n001 = dot(g001, vec3(Pf0.xy, Pf1.z));
            float n101 = dot(g101, vec3(Pf1.x, Pf0.y, Pf1.z));
            float n011 = dot(g011, vec3(Pf0.x, Pf1.yz));
            float n111 = dot(g111, Pf1);
          
            vec3 fade_xyz = fade(Pf0);
            vec4 n_z = mix(vec4(n000, n100, n010, n110), vec4(n001, n101, n011, n111), fade_xyz.z);
            vec2 n_yz = mix(n_z.xy, n_z.zw, fade_xyz.y);
            float n_xyz = mix(n_yz.x, n_yz.y, fade_xyz.x); 
            return 2.2 * n_xyz;
          }
  
          // from https://www.shadertoy.com/view/ltfXR4
          vec3 catmul_rom(vec3 p0, vec3 p1, vec3 p2, vec3 p3, float t)
          {
              return 0.5 * (
                  (2.0 * p1) +
                  (-p0 + p2) * t +
                  (2.0 * p0 - 5.0 * p1 + 4.0 * p2 - p3) * t * t +
                  (-p0 + 3.0 * p1 - 3.0 * p2 + p3) * t * t * t);
          }
  
          vec3 color_spline(float t, bool wrap)
          {
              t = clamp(t, 0.0, 1.0);
              
              const int s = 7;
              
              vec3 p[s];
              p[0] = vec3(87,24,69) / 255.0;
              p[1] = vec3(144,13,62) / 255.0;
              p[2] = vec3(200,0,57) / 255.0;
              p[3] = vec3(255,86,51) / 255.0;
              p[4] = vec3(255,195,0) / 255.0;
              
              p[s-2] = p[0];
              p[s-1] = p[1];
              
              float m = wrap ? float(s - 2) : float(s - 3);
              float d = m * t;
              
              int b = int(d);
              float dt = d - floor(d);
              
              return catmul_rom(p[((b-1)+s)%s], p[b], p[b+1], p[(b+2)%s], dt);
          }
  
          `
        );
        shader.fragmentShader = shader.fragmentShader.replace(
          "#include <dithering_fragment>",
          `#include <dithering_fragment>
          float n = smoothstep(.5-width, .5+width, .5 + .5 * cnoise(scale*vWorldPosition.xyz));
          gl_FragColor.rgb *= color_spline(n, true);
          gl_FragColor.rgb += offset;
          `
        );
      };
    }
  }
  
  function generateParams(gui, material) {
    const params = material.params;
    gui
      .add(params, "scale", 0.1, 5)
      .onChange((v) => (material.uniforms.scale.value = v));
    //gui.add(params, "offset", 0, 1).onChange((v) => (material.metalness = v));
  }
  
  export { Material, generateParams };
  