105 lines
3.9 KiB
JavaScript
105 lines
3.9 KiB
JavaScript
"use strict";
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Object.defineProperty(exports, Symbol.toStringTag, { value: "Module" });
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const THREE = require("three");
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const _face = /* @__PURE__ */ new THREE.Triangle();
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const _color = /* @__PURE__ */ new THREE.Vector3();
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class MeshSurfaceSampler {
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constructor(mesh) {
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let geometry = mesh.geometry;
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if (geometry.index) {
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console.warn("THREE.MeshSurfaceSampler: Converting geometry to non-indexed BufferGeometry.");
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geometry = geometry.toNonIndexed();
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}
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this.geometry = geometry;
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this.randomFunction = Math.random;
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this.positionAttribute = this.geometry.getAttribute("position");
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this.colorAttribute = this.geometry.getAttribute("color");
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this.weightAttribute = null;
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this.distribution = null;
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}
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setWeightAttribute(name) {
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this.weightAttribute = name ? this.geometry.getAttribute(name) : null;
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return this;
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}
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build() {
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const positionAttribute = this.positionAttribute;
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const weightAttribute = this.weightAttribute;
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const faceWeights = new Float32Array(positionAttribute.count / 3);
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for (let i = 0; i < positionAttribute.count; i += 3) {
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let faceWeight = 1;
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if (weightAttribute) {
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faceWeight = weightAttribute.getX(i) + weightAttribute.getX(i + 1) + weightAttribute.getX(i + 2);
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}
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_face.a.fromBufferAttribute(positionAttribute, i);
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_face.b.fromBufferAttribute(positionAttribute, i + 1);
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_face.c.fromBufferAttribute(positionAttribute, i + 2);
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faceWeight *= _face.getArea();
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faceWeights[i / 3] = faceWeight;
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}
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this.distribution = new Float32Array(positionAttribute.count / 3);
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let cumulativeTotal = 0;
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for (let i = 0; i < faceWeights.length; i++) {
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cumulativeTotal += faceWeights[i];
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this.distribution[i] = cumulativeTotal;
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}
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return this;
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}
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setRandomGenerator(randomFunction) {
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this.randomFunction = randomFunction;
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return this;
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}
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sample(targetPosition, targetNormal, targetColor) {
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const faceIndex = this.sampleFaceIndex();
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return this.sampleFace(faceIndex, targetPosition, targetNormal, targetColor);
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}
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sampleFaceIndex() {
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const cumulativeTotal = this.distribution[this.distribution.length - 1];
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return this.binarySearch(this.randomFunction() * cumulativeTotal);
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}
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binarySearch(x) {
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const dist = this.distribution;
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let start = 0;
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let end = dist.length - 1;
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let index = -1;
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while (start <= end) {
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const mid = Math.ceil((start + end) / 2);
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if (mid === 0 || dist[mid - 1] <= x && dist[mid] > x) {
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index = mid;
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break;
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} else if (x < dist[mid]) {
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end = mid - 1;
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} else {
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start = mid + 1;
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}
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}
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return index;
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}
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sampleFace(faceIndex, targetPosition, targetNormal, targetColor) {
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let u = this.randomFunction();
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let v = this.randomFunction();
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if (u + v > 1) {
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u = 1 - u;
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v = 1 - v;
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}
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_face.a.fromBufferAttribute(this.positionAttribute, faceIndex * 3);
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_face.b.fromBufferAttribute(this.positionAttribute, faceIndex * 3 + 1);
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_face.c.fromBufferAttribute(this.positionAttribute, faceIndex * 3 + 2);
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targetPosition.set(0, 0, 0).addScaledVector(_face.a, u).addScaledVector(_face.b, v).addScaledVector(_face.c, 1 - (u + v));
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if (targetNormal !== void 0) {
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_face.getNormal(targetNormal);
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}
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if (targetColor !== void 0 && this.colorAttribute !== void 0) {
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_face.a.fromBufferAttribute(this.colorAttribute, faceIndex * 3);
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_face.b.fromBufferAttribute(this.colorAttribute, faceIndex * 3 + 1);
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_face.c.fromBufferAttribute(this.colorAttribute, faceIndex * 3 + 2);
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_color.set(0, 0, 0).addScaledVector(_face.a, u).addScaledVector(_face.b, v).addScaledVector(_face.c, 1 - (u + v));
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targetColor.r = _color.x;
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targetColor.g = _color.y;
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targetColor.b = _color.z;
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}
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return this;
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}
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}
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exports.MeshSurfaceSampler = MeshSurfaceSampler;
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//# sourceMappingURL=MeshSurfaceSampler.cjs.map
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