private _compute()

in packages/common/src/math/path3.ts [100:156]

• 45 lines of code
• 9 McCabe index (conditional complexity)

	private _compute(firstNormal?: Vector3): void {
		const l = this._curve.length;

		// first and last tangents
		this._tangents[0] = this._getFirstNonNullVector(0);
		if (!this._raw) {
			this._tangents[0].normalize();
		}
		this._tangents[l - 1] = this._curve[l - 1].subtract(this._curve[l - 2]);
		if (!this._raw) {
			this._tangents[l - 1].normalize();
		}

		// normals and binormals at first point : arbitrary vector with _normalVector()
		const tg0 = this._tangents[0];
		const pp0 = this._normalVector(this._curve[0], tg0, firstNormal);
		this._normals[0] = pp0;
		if (!this._raw) {
			this._normals[0].normalize();
		}
		this._binormals[0] = Vector3.Cross(tg0, this._normals[0]);
		if (!this._raw) {
			this._binormals[0].normalize();
		}
		this._distances[0] = 0.0;

		// normals and binormals : next points
		let prev: Vector3;        // previous vector (segment)
		let cur: Vector3;         // current vector (segment)
		let curTang: Vector3;     // current tangent
		// previous normal
		let prevBinor: Vector3;   // previous binormal

		for (let i = 1; i < l; i++) {
			// tangents
			prev = this._getLastNonNullVector(i);
			if (i < l - 1) {
				cur = this._getFirstNonNullVector(i);
				this._tangents[i] = prev.add(cur);
				this._tangents[i].normalize();
			}
			this._distances[i] = this._distances[i - 1] + prev.length();

			// normals and binormals
			// http://www.cs.cmu.edu/afs/andrew/scs/cs/15-462/web/old/asst2camera.html
			curTang = this._tangents[i];
			prevBinor = this._binormals[i - 1];
			this._normals[i] = Vector3.Cross(prevBinor, curTang);
			if (!this._raw) {
				this._normals[i].normalize();
			}
			this._binormals[i] = Vector3.Cross(curTang, this._normals[i]);
			if (!this._raw) {
				this._binormals[i].normalize();
			}
		}
	}