ts-ritofile/src/structures/quaternion.ts

TypeScript library for reading and writing League of Legends game file formats

import { JsonSerializable } from '../core/json-encoder';

export class Quaternion implements JsonSerializable {
  public x: number;
  public y: number;
  public z: number;
  public w: number;

  constructor(x: number, y: number, z: number, w: number) {
    this.x = x;
    this.y = y;
    this.z = z;
    this.w = w;
  }

  multiply(scalar: number): Quaternion {
    this.x *= scalar;
    this.y *= scalar;
    this.z *= scalar;
    this.w *= scalar;
    return this;
  }

  static slerp(quat1: Quaternion, quat2: Quaternion, weight: number): Quaternion {
    if (weight < 0.005) return quat1;
    if (weight > 0.995) return quat2;

    const epsilon = 1e-6;
    let cosOmega = quat1.x * quat2.x + quat1.y * quat2.y + quat1.z * quat2.z + quat1.w * quat2.w;
    let flip = false;

    if (cosOmega < 0.0) {
      flip = true;
      cosOmega = -cosOmega;
    }

    let s1: number, s2: number;

    if (cosOmega > (1.0 - epsilon)) {
      s1 = 1.0 - weight;
      s2 = flip ? -weight : weight;
    } else {
      const omega = Math.acos(cosOmega);
      const invSinOmega = 1 / Math.sin(omega);
      s1 = Math.sin((1.0 - weight) * omega) * invSinOmega;
      s2 = flip 
        ? -Math.sin(weight * omega) * invSinOmega 
        : Math.sin(weight * omega) * invSinOmega;
    }

    return new Quaternion(
      s1 * quat1.x + s2 * quat2.x,
      s1 * quat1.y + s2 * quat2.y,
      s1 * quat1.z + s2 * quat2.z,
      s1 * quat1.w + s2 * quat2.w
    );
  }

  toString(): string {
    return `${this.x.toFixed(4)} ${this.y.toFixed(4)} ${this.z.toFixed(4)} ${this.w.toFixed(4)}`;
  }

  toArray(): number[] {
    return [this.x, this.y, this.z, this.w];
  }

  __json__(): number[] {
    return this.toArray();
  }

  // Keep toJSON for standard JavaScript compatibility
  toJSON(): number[] {
    return this.__json__();
  }
}