avocado-old/packages/physics/rectangle.js

import {compose} from '@avocado/core';
import {Vector} from '@avocado/math';

import {PolygonShape} from './polygon';

const decorate = compose(
  Vector.Mixin('size', 'width', 'height', {
    default: [0, 0],
    track: true,
  }),
);

export class RectangleShape extends decorate(PolygonShape) {

  constructor() {
    super();
    this.on(['positionChanged', 'sizeChanged'], this.onVerticesChanged, this);
  }

  destroy() {
    super.destroy();
    this.off(['positionChanged', 'sizeChanged'], this.onVerticesChanged);
  }

  fromJSON(json) {
    super.fromJSON(json);
    const keys = [
      'size',
    ];
    for (const key of keys) {
      if (json[key]) {
        this[key] = json[key];
      }
    }
    return this;
  }

  onVerticesChanged() {
    const halfSize = Vector.scale(this.size, 0.5);
    const width = this.width - 0.001;
    const height = this.height - 0.001;
    const position = Vector.add(this.position, Vector.scale(halfSize, -1));
    this.vertices = [
      position,
      Vector.add(position, [width, 0]),
      Vector.add(position, [width, height]),
      Vector.add(position, [0, height]),
    ];
  }

  toJSON() {
    return {
      ...super.toJSON(),
      type: 'rectangle',
      position: this.position,
      size: this.size,
    }
  }

}