@giro3d/giro3d/core/OffsetScale.js

A JS/WebGL framework for 3D geospatial data visualization

import { Vector2, Vector4 } from 'three';

/**
 * Describes a transformation of a point in 2D space without rotation.
 * Typically used for to transform texture coordinates.
 */
export default class OffsetScale extends Vector4 {
  isOffsetScale = true;
  get offsetX() {
    return this.x;
  }
  get offsetY() {
    return this.y;
  }
  get scaleX() {
    return this.z;
  }
  get scaleY() {
    return this.w;
  }
  constructor(offsetX, offsetY, scaleX, scaleY) {
    super(offsetX, offsetY, scaleX, scaleY);
  }
  static identity() {
    return new OffsetScale(0, 0, 1, 1);
  }

  /**
   * Transforms the point.
   * @param point - The point to transform.
   * @param target - The target to fill with the transformed point.
   * @returns The transformed point.
   */
  transform(point, target = new Vector2()) {
    target.x = point.x * this.scaleX + this.offsetX;
    target.y = point.y * this.scaleY + this.offsetY;
    return target;
  }
  combine(offsetScale, target = new OffsetScale()) {
    target.copy(this);
    target.x += offsetScale.x * target.z;
    target.y += offsetScale.y * target.w;
    target.z *= offsetScale.z;
    target.w *= offsetScale.w;
    return target;
  }
}