src/buffer/ellipsoidgeometry-buffer.js

/**
 * @file Ellipsoid Geometry Buffer
 * @author Alexander Rose <alexander.rose@weirdbyte.de>
 * @private
 */

import { IcosahedronBufferGeometry, Vector3 } from '../../lib/three.es6.js'

import { defaults } from '../utils.js'
import GeometryBuffer from './geometry-buffer.js'

const scale = new Vector3()
const target = new Vector3()
const up = new Vector3()
const eye = new Vector3(0, 0, 0)

/**
 * Ellipsoid geometry buffer. Draws ellipsoids.
 *
 * @example
 * var ellipsoidGeometryBuffer = new EllipsoidGeometryBuffer({
 *   position: new Float32Array([ 0, 0, 0 ]),
 *   color: new Float32Array([ 1, 0, 0 ]),
 *   radius: new Float32Array([ 1 ]),
 *   majorAxis: new Float32Array([ 1, 1, 0 ]),
 *   minorAxis: new Float32Array([ 0.5, 0, 0.5 ]),
 * });
 */
class EllipsoidGeometryBuffer extends GeometryBuffer {
  constructor (data, params) {
    const p = params || {}
    const detail = defaults(p.sphereDetail, 2)
    const geo = new IcosahedronBufferGeometry(1, detail)

    super(data, p, geo)

    this.setAttributes(data, true)
  }

  applyPositionTransform (matrix, i, i3) {
    target.fromArray(this._majorAxis, i3)
    up.fromArray(this._minorAxis, i3)
    matrix.lookAt(eye, target, up)

    scale.set(this._radius[ i ], up.length(), target.length())
    matrix.scale(scale)
  }

  setAttributes (data, initNormals) {
    if (data.radius) this._radius = data.radius
    if (data.majorAxis) this._majorAxis = data.majorAxis
    if (data.minorAxis) this._minorAxis = data.minorAxis

    super.setAttributes(data, initNormals)
  }

  get updateNormals () { return true }
}

export default EllipsoidGeometryBuffer