awv3/three/ringgeometry.js

⚡ AWV3 embedded CAD

import _inheritsLoose from "@babel/runtime/helpers/inheritsLoose";
import * as THREE from 'three'; //note: number of vertices is constant in order to use the same vertex buffer

var RingGeometry =
/*#__PURE__*/
function (_THREE$BufferGeometry) {
  _inheritsLoose(RingGeometry, _THREE$BufferGeometry);

  function RingGeometry(segments) {
    var _this;

    _this = _THREE$BufferGeometry.call(this) || this;
    _this.parameters = {
      thetaSegments: segments,
      innerRadius: 1.0,
      outerRadius: 2.0,
      thetaStart: 0.0,
      thetaLength: 2 * Math.PI
    };
    var vertsCount = (segments + 1) * 2;
    var facesCount = segments * 2;

    _this.setIndex(new THREE.BufferAttribute(new Uint32Array(facesCount * 3), 1));

    _this.addAttribute('position', new THREE.BufferAttribute(new Float32Array(vertsCount * 3), 3));

    _this.addAttribute('normal', new THREE.BufferAttribute(new Float32Array(vertsCount * 3), 3));

    _this.attributes.position.dynamic = true;
    var f = 0;

    for (var i = 0; i < segments; i++) {
      var _arr = [2 * i, 2 * i + 2, 2 * i + 3, 2 * i + 3, 2 * i + 1, 2 * i];

      for (var _i = 0; _i < _arr.length; _i++) {
        var idx = _arr[_i];
        _this.index.array[f++] = idx;
      }
    }

    var n = 0;

    for (var _i2 = 0; _i2 < vertsCount; _i2++) {
      var _arr2 = [0, 0, 1];

      for (var _i3 = 0; _i3 < _arr2.length; _i3++) {
        var crd = _arr2[_i3];
        _this.attributes.normal.array[n++] = crd;
      }
    }

    _this.updateParameters(_this.parameters);

    return _this;
  }

  var _proto = RingGeometry.prototype;

  _proto.updateParameters = function updateParameters(newParams) {
    Object.assign(this.parameters, newParams);
    var segments = this.parameters.thetaSegments;
    var vertexBuffer = this.attributes.position.array;

    for (var i = 0; i <= segments; i++) {
      var angle = this.parameters.thetaStart + this.parameters.thetaLength * i / segments;
      var cosA = Math.cos(angle),
          sinA = Math.sin(angle);
      var innerPos = new THREE.Vector3(cosA, sinA, 0).multiplyScalar(this.parameters.innerRadius);
      var outerPos = new THREE.Vector3(cosA, sinA, 0).multiplyScalar(this.parameters.outerRadius);
      vertexBuffer[6 * i + 0] = innerPos.x;
      vertexBuffer[6 * i + 1] = innerPos.y;
      vertexBuffer[6 * i + 2] = innerPos.z;
      vertexBuffer[6 * i + 3] = outerPos.x;
      vertexBuffer[6 * i + 4] = outerPos.y;
      vertexBuffer[6 * i + 5] = outerPos.z;
    }

    this.attributes.position.needsUpdate = true; //Note: this update may be done faster:

    this.computeBoundingSphere();
  };

  return RingGeometry;
}(THREE.BufferGeometry);

export { RingGeometry as default };