@awayjs/scene/lib/prefabs/PrimitiveTorusPrefab.ts

AwayJS scene classes

import { IMaterial, ElementsType, ElementsBase, TriangleElements } from '@awayjs/renderer';

import { PrimitivePrefabBase } from '../prefabs/PrimitivePrefabBase';

/**
 * A UV Cylinder primitive sprite.
 */
export class PrimitiveTorusPrefab extends PrimitivePrefabBase {
	private _radius: number;
	private _tubeRadius: number;
	private _segmentsR: number;
	private _segmentsT: number;
	private _yUp: boolean;
	private _numVertices: number = 0;

	/**
	 * The radius of the torus.
	 */
	public get radius(): number {
		return this._radius;
	}

	public set radius(value: number) {
		this._radius = value;
		this._pInvalidatePrimitive();
	}

	/**
	 * The radius of the inner tube of the torus.
	 */
	public get tubeRadius(): number {
		return this._tubeRadius;
	}

	public set tubeRadius(value: number) {
		this._tubeRadius = value;
		this._pInvalidatePrimitive();
	}

	/**
	 * Defines the number of horizontal segments that make up the torus. Defaults to 16.
	 */
	public get segmentsR(): number {
		return this._segmentsR;
	}

	public set segmentsR(value: number) {
		this._segmentsR = value;
		this._pInvalidatePrimitive();
		this._pInvalidateUVs();
	}

	/**
	 * Defines the number of vertical segments that make up the torus. Defaults to 8.
	 */
	public get segmentsT(): number {
		return this._segmentsT;
	}

	public set segmentsT(value: number) {
		this._segmentsT = value;
		this._pInvalidatePrimitive();
		this._pInvalidateUVs();
	}

	/**
	 * Defines whether the torus poles should lay on the Y-axis (true) or on the Z-axis (false).
	 */
	public get yUp(): boolean {
		return this._yUp;
	}

	public set yUp(value: boolean) {
		this._yUp = value;
		this._pInvalidatePrimitive();
	}

	/**
	 * Creates a new <code>Torus</code> object.
	 * @param radius The radius of the torus.
	 * @param tuebRadius The radius of the inner tube of the torus.
	 * @param segmentsR Defines the number of horizontal segments that make up the torus.
	 * @param segmentsT Defines the number of vertical segments that make up the torus.
	 * @param yUp Defines whether the torus poles should lay on the Y-axis (true) or on the Z-axis (false).
	 */
	constructor(material: IMaterial = null, elementsType: string = 'triangle',
		radius: number = 50, tubeRadius: number = 50,
		segmentsR: number = 16, segmentsT: number = 8, yUp: boolean = true) {
		super(material, elementsType);

		this._radius = radius;
		this._tubeRadius = tubeRadius;
		this._segmentsR = segmentsR;
		this._segmentsT = segmentsT;
		this._yUp = yUp;
	}

	/**
	 * @inheritDoc
	 */
	public _pBuildGraphics(target: ElementsBase, elementsType: string): void {
		let indices: Uint16Array;
		let positions: ArrayBufferView;
		let normals: Float32Array;
		let tangents: Float32Array;
		let stride: number;

		let i: number, j: number;
		let x: number, y: number, z: number, nx: number, ny: number, nz: number,
			revolutionAngleR: number, revolutionAngleT: number;
		let vidx: number;
		let fidx: number;
		let numIndices: number = 0;

		if (elementsType == ElementsType.TRIANGLE) {

			const triangleGraphics: TriangleElements = <TriangleElements> target;

			// evaluate target number of vertices, triangles and indices
			this._numVertices = (this._segmentsT + 1) * (this._segmentsR + 1);
			// segmentsT + 1 because of closure, segmentsR + 1 because of closure
			numIndices = this._segmentsT * this._segmentsR * 6;
			// each level has segmentR quads, each of 2 triangles

			// need to initialize raw arrays or can be reused?
			if (this._numVertices == triangleGraphics.numVertices) {
				triangleGraphics.invalidateIndices();
				triangleGraphics.invalidateVertices(triangleGraphics.positions);
				triangleGraphics.invalidateVertices(triangleGraphics.normals);
				triangleGraphics.invalidateVertices(triangleGraphics.tangents);
			} else {
				triangleGraphics.setIndices(new Uint16Array(numIndices));
				triangleGraphics.setPositions(new Float32Array(this._numVertices * 3));
				triangleGraphics.setNormals(new Float32Array(this._numVertices * 3));
				triangleGraphics.setTangents(new Float32Array(this._numVertices * 3));

				this._pInvalidateUVs();
			}

			indices = triangleGraphics.indices.get(triangleGraphics.numElements);
			positions = triangleGraphics.positions.get(this._numVertices);
			normals = triangleGraphics.normals.get(this._numVertices);
			tangents = triangleGraphics.tangents.get(this._numVertices);
			stride = triangleGraphics.concatenatedBuffer.stride / 4;

			vidx = 0;
			fidx = 0;

			// evaluate revolution steps
			const revolutionAngleDeltaR: number = 2 * Math.PI / this._segmentsR;
			const revolutionAngleDeltaT: number = 2 * Math.PI / this._segmentsT;

			let comp1: number, comp2: number;
			let t1: number, t2: number, n1: number, n2: number;
			let startIndex: number = 0;
			let nextVertexIndex: number = 0;

			// surface
			let a: number, b: number, c: number, d: number, length: number;

			for (j = 0; j <= this._segmentsT; ++j) {

				startIndex = vidx;

				for (i = 0; i <= this._segmentsR; ++i) {

					// revolution vertex
					revolutionAngleR = i * revolutionAngleDeltaR;
					revolutionAngleT = j * revolutionAngleDeltaT;

					length = Math.cos(revolutionAngleT);
					nx = length * Math.cos(revolutionAngleR);
					ny = length * Math.sin(revolutionAngleR);
					nz = Math.sin(revolutionAngleT);

					x = this._radius * Math.cos(revolutionAngleR) + this._tubeRadius * nx;
					y = this._radius * Math.sin(revolutionAngleR) + this._tubeRadius * ny;
					z = (j == this._segmentsT) ? 0 : this._tubeRadius * nz;

					if (this._yUp) {

						n1 = -nz;
						n2 = ny;
						t1 = 0;
						t2 = (length ? nx / length : x / this._radius);
						comp1 = -z;
						comp2 = y;

					} else {
						n1 = ny;
						n2 = nz;
						t1 = (length ? nx / length : x / this._radius);
						t2 = 0;
						comp1 = y;
						comp2 = z;
					}

					if (i == this._segmentsR) {
						positions[vidx] = x;
						positions[vidx + 1] = positions[startIndex + 1];
						positions[vidx + 2] = positions[startIndex + 2];
					} else {
						positions[vidx] = x;
						positions[vidx + 1] = comp1;
						positions[vidx + 2] = comp2;
					}

					normals[vidx] = nx;
					normals[vidx + 1] = n1;
					normals[vidx + 2] = n2;
					tangents[vidx] = -(length ? ny / length : y / this._radius);
					tangents[vidx + 1] = t1;
					tangents[vidx + 2] = t2;

					vidx += stride;

					// close triangle
					if (i > 0 && j > 0) {
						a = nextVertexIndex; // current
						b = nextVertexIndex - 1; // previous
						c = b - this._segmentsR - 1; // previous of last level
						d = a - this._segmentsR - 1; // current of last level

						indices[fidx++] = a;
						indices[fidx++] = b;
						indices[fidx++] = c;

						indices[fidx++] = a;
						indices[fidx++] = c;
						indices[fidx++] = d;
					}

					nextVertexIndex++;
				}
			}

		} else if (elementsType == ElementsType.LINE) {
			//TODO
		}
	}

	/**
	 * @inheritDoc
	 */
	public _pBuildUVs(target: ElementsBase, elementsType: string): void {

		let i: number, j: number;
		let uvs: ArrayBufferView;
		let stride: number;

		if (elementsType == ElementsType.TRIANGLE) {

			const triangleGraphics: TriangleElements = <TriangleElements> target;

			// need to initialize raw array or can be reused?
			if (triangleGraphics.uvs && this._numVertices == triangleGraphics.numVertices) {
				triangleGraphics.invalidateVertices(triangleGraphics.uvs);
			} else {
				triangleGraphics.setUVs(new Float32Array(this._numVertices * 2));
			}

			uvs = triangleGraphics.uvs.get(this._numVertices);
			stride = triangleGraphics.uvs.stride;

			// current uv component index
			let index: number = 0;

			// surface
			for (j = 0; j <= this._segmentsT; ++j) {
				for (i = 0; i <= this._segmentsR; ++i) {
					// revolution vertex
					uvs[index] = (i / this._segmentsR) * this._scaleU;
					uvs[index + 1] = (j / this._segmentsT) * this._scaleV;

					index += stride;
				}
			}

		} else if (elementsType == ElementsType.LINE) {
			//nothing to do here
		}
	}
}