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

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

import { Vec2 } from "../../core/math/vec2.js";
import { calculateTangents } from "./geometry-utils.js";
import { Geometry } from "./geometry.js";
class PlaneGeometry extends Geometry {
  /**
   * Create a new PlaneGeometry instance.
   *
   * By default, the constructor creates a plane centered on the object space origin with a width
   * and length of 1 and 5 segments in either axis (50 triangles). The normal vector of the plane is
   * aligned along the positive Y axis. The plane is created with UVs in the range of 0 to 1.
   *
   * @param {object} [opts] - Options object.
   * @param {Vec2} [opts.halfExtents] - The half dimensions of the plane in the X and Z axes.
   * Defaults to [0.5, 0.5].
   * @param {number} [opts.widthSegments] - The number of divisions along the X axis of the plane.
   * Defaults to 5.
   * @param {number} [opts.lengthSegments] - The number of divisions along the Z axis of the plane.
   * Defaults to 5.
   * @param {boolean} [opts.calculateTangents] - Generate tangent information. Defaults to false.
   * @example
   * const geometry = new pc.PlaneGeometry({
   *     halfExtents: new pc.Vec2(1, 1),
   *     widthSegments: 10,
   *     lengthSegments: 10
   * });
   */
  constructor(opts = {}) {
    super();
    const he = opts.halfExtents ?? new Vec2(0.5, 0.5);
    const ws = opts.widthSegments ?? 5;
    const ls = opts.lengthSegments ?? 5;
    const positions = [];
    const normals = [];
    const uvs = [];
    const indices = [];
    let vcounter = 0;
    for (let i = 0; i <= ws; i++) {
      for (let j = 0; j <= ls; j++) {
        const x = -he.x + 2 * he.x * i / ws;
        const y = 0;
        const z = -(-he.y + 2 * he.y * j / ls);
        const u = i / ws;
        const v = j / ls;
        positions.push(x, y, z);
        normals.push(0, 1, 0);
        uvs.push(u, 1 - v);
        if (i < ws && j < ls) {
          indices.push(vcounter + ls + 1, vcounter + 1, vcounter);
          indices.push(vcounter + ls + 1, vcounter + ls + 2, vcounter + 1);
        }
        vcounter++;
      }
    }
    this.positions = positions;
    this.normals = normals;
    this.uvs = uvs;
    this.uvs1 = uvs;
    this.indices = indices;
    if (opts.calculateTangents) {
      this.tangents = calculateTangents(positions, normals, uvs, indices);
    }
  }
}
export {
  PlaneGeometry
};