playcanvas/build/playcanvas.dbg/src/scene/geometry/dome-geometry.js

Open-source WebGL/WebGPU 3D engine for the web

import { SphereGeometry } from "./sphere-geometry.js";
class DomeGeometry extends SphereGeometry {
  /**
   * Create a new DomeGeometry instance.
   *
   * By default, the constructor creates a dome with a radius of 0.5, 16 latitude bands and 16
   * longitude bands. The dome is created with UVs in the range of 0 to 1.
   *
   * @param {object} [opts] - Options object.
   * @param {number} [opts.latitudeBands] - The number of divisions along the latitudinal axis of
   * the sphere. Defaults to 16.
   * @param {number} [opts.longitudeBands] - The number of divisions along the longitudinal axis of
   * the sphere. Defaults to 16.
   * @example
   * const geometry = new pc.DomeGeometry({
   *     latitudeBands: 32,
   *     longitudeBands: 32
   * });
   */
  constructor(opts = {}) {
    const radius = 0.5;
    const latitudeBands = opts.latitudeBands ?? 16;
    const longitudeBands = opts.longitudeBands ?? 16;
    super({
      radius,
      latitudeBands,
      longitudeBands
    });
    const bottomLimit = 0.1;
    const curvatureRadius = 0.95;
    const curvatureRadiusSq = curvatureRadius * curvatureRadius;
    const positions = this.positions;
    for (let i = 0; i < positions.length; i += 3) {
      const x = positions[i] / radius;
      let y = positions[i + 1] / radius;
      const z = positions[i + 2] / radius;
      if (y < 0) {
        y *= 0.3;
        if (x * x + z * z < curvatureRadiusSq) {
          y = -bottomLimit;
        }
      }
      y += bottomLimit;
      y *= radius;
      positions[i + 1] = y;
    }
  }
}
export {
  DomeGeometry
};