Initial commit

js/ColorMapPass.js

@@ -0,0 +1,81 @@
+/**
+ * @author rezmason
+ */
+
+const easeInOutQuad = input => {
+  input = Math.max(0, Math.min(1, input));
+  if (input < 0.5) {
+    return 2 * input * input;
+  }
+  input -= 1;
+  return 1 - 2 * input * input;
+}
+
+THREE.ColorMapPass = function (entries) {
+  const colors = Array(256).fill().map(_ => new THREE.Vector3());
+  const sortedEntries = entries.slice().sort((e1, e2) => e1.at - e2.at).map(entry => ({
+    color: entry.color,
+    at255: Math.floor(Math.max(Math.min(1, entry.at), 0) * (colors.length - 1))
+  }));
+  sortedEntries.unshift({color:sortedEntries[0].color, at255:0});
+  sortedEntries.push({color:sortedEntries[sortedEntries.length - 1].color, at255:255});
+  sortedEntries.forEach((entry, index) => {
+    colors[entry.at255].copy(entry.color);
+    if (index + 1 < sortedEntries.length) {
+      const nextEntry = sortedEntries[index + 1];
+      const diff = nextEntry.at255 - entry.at255;
+      for (let i = 0; i < diff; i++) {
+        colors[entry.at255 + i].lerpVectors(entry.color, nextEntry.color, i / diff);
+      }
+    }
+  });
+  const values = new Uint8Array([].concat(...colors.map(color => color.toArray().map(component => Math.floor(component * 255)))));
+
+  this.dataTexture = new THREE.DataTexture(
+    values,
+    values.length / 3,
+    1,
+    THREE.RGBFormat,
+    THREE.UnsignedByteType,
+    THREE.UVMapping);
+  this.dataTexture.magFilter = THREE.LinearFilter;
+  this.dataTexture.needsUpdate = true;
+
+  this.shader = {
+    uniforms: {
+      tDiffuse: { value: null },
+      tColorData: { value: this.dataTexture }
+    },
+
+    vertexShader: `
+      varying vec2 vUv;
+      void main() {
+        vUv = uv;
+        gl_Position = vec4( position, 1.0 );
+      }
+    `,
+
+    fragmentShader: `
+      uniform sampler2D tDiffuse;
+      uniform sampler2D tColorData;
+      varying vec2 vUv;
+
+      void main() {
+        gl_FragColor = vec4(
+          texture2D( tColorData, vec2( texture2D( tDiffuse, vUv ).r, 0.0 ) ).rgb,
+          1.0
+        );
+      }
+    `
+  };
+
+  THREE.ShaderPass.call(this, this.shader);
+};
+
+THREE.ColorMapPass.prototype = Object.assign( Object.create( THREE.Pass.prototype ), {
+  constructor: THREE.ColorMapPass,
+  render: function() {
+    this.uniforms[ "tColorData" ].value = this.dataTexture;
+    THREE.ShaderPass.prototype.render.call(this, ...arguments);
+  }
+});