avocado-old/packages/topdown/tiles.js

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

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

class TilesBase {

  fromJSON(json) {
    if (json.size) {
      this.size = json.size;
    }
    if (json.data) {
      this.data = json.data;
    }
    return this;
  }

  get rectangle() {
    return Rectangle.compose([0, 0], this.size);
  }

  setTileAt(x, y, tile) {
    const index = y * this.width + x;
    if (index < 0 || index >= this.data.length) {
      return;
    }
    this.data[index] = tile;
  }

  slice(rectangle) {
    const tilesRectangle = this.rectangle;
    // Get intersection.
    if (!Rectangle.intersects(rectangle, tilesRectangle)) {
      return [];
    }
    let [x, y, sliceWidth, sliceHeight] = Rectangle.intersection(
      rectangle,
      tilesRectangle,
    );
    // No muls in the loop.
    let sliceRow = y * sliceWidth;
    const dataWidth = this.width;
    let dataRow = y * dataWidth;
    // Copy slice.
    const slice = new Array(sliceWidth * sliceHeight);
    for (let j = 0; j < sliceHeight; ++j) {
      for (let i = 0; i < sliceWidth; ++i) {
        slice[sliceRow + x] = this.data[dataRow + x];
        x++;
      }
      sliceRow += sliceWidth;
      dataRow += dataWidth;
      x -= sliceWidth;
    }
    return slice;
  }

  tileAt(x, y) {
    return this.data[y * this.width + x];
  }

  toJSON() {

  }

}

export class Tiles extends decorate(TilesBase) {}