avocado-old/packages/physics/polygon.js

import {Rectangle, Vector, Vertice} from '@avocado/math';

import {Shape} from './shape';

export class PolygonShape extends Shape {

  constructor() {
    super();
    this._translatedVertices = [];
    this._vertices = [];
    this.on([
      'parentOriginChanged',
      'parentRotationChanged',
      'parentScaleChanged',
      'originChanged',
      'rotationChanged',
      'scaleChanged',
      'verticesChanged',
    ], this.onRecalculateVertices, this);
  }

  destroy() {
    super.destroy();
    this.off([
      'parentOriginChanged',
      'parentRotationChanged',
      'parentScaleChanged',
      'originChanged',
      'rotationChanged',
      'scaleChanged',
      'verticesChanged',
    ], this.onRecalculateVertices);
  }

  *[Symbol.iterator]() {
    for (const vertice of this._translatedVertices) {
      yield vertice;
    }
  }

  get aabb() {
    if (0 === this._vertices.length) {
      return [0, 0, 0, 0];
    }
    const min = [Infinity, Infinity];
    const max = [-Infinity, -Infinity];
    for (const vertice of this._translatedVertices) {
      min[0] = vertice[0] < min[0] ? vertice[0] : min[0];
      min[1] = vertice[1] < min[1] ? vertice[1] : min[1];
      max[0] = vertice[0] > max[0] ? vertice[0] : max[0];
      max[1] = vertice[1] > max[1] ? vertice[1] : max[1];
    }
    return Rectangle.translated(
      [min[0], min[1], max[0] - min[0], max[1] - min[1]],
      this.position
    );
  }

  fromJSON(json) {
    super.fromJSON(json);
    if (json.vertices) {
      this.vertices = json.vertices;
    }
    return this;
  }

  onRecalculateVertices() {
    const parentOrigin = this.parent ? this.parent.origin : [0, 0];
    const origin = Vector.add(this.origin, parentOrigin);
    const parentRotation = this.parent ? this.parent.rotation : 0;
    const rotation = this.rotation + parentRotation;
    const parentScale = this.parent ? this.parent.scale : 1;
    const scale = this.scale * parentScale;
    this._translatedVertices = this._vertices.map((vertice) => {
      return Vertice.translate(vertice, origin, rotation, scale);
    });
    this.emit('aabbChanged');
  }

  get vertices() {
    return this._vertices;
  }

  set vertices(vertices) {
    this._vertices = [...vertices];
    this.emit('verticesChanged');
  }

  toJSON() {
    return {
      ...super.toJSON(),
      type: 'polygon',
      vertices: [...this._vertices]
    }
  }

}