so://phie

blob: 00188553191e49cd1cb2936fedf4e0afc6e50dee (1137 bytes)[doc][blame][raw]

 1import { scaleCanvas } from '../util/canvas.js';
 2
 3const cache = new Map();
 4const canvas = document.createElement('canvas');
 5const g = canvas.getContext('2d');
 6
 7export default class Bitmap {
 8	static from(sprite, width, height) {
 9		const key = `${sprite.path}:${width}x${height}`;
10		if(!cache.has(key)) {
11			cache.set(key, new Bitmap(sprite.image, width, height));
12		}
13		return cache.get(key);
14	}
15	constructor(image, width, height) {
16		this.image = image;
17		this.width = width;
18		this.height = height;
19		scaleCanvas(canvas, width, height);
20		g.imageSmoothingEnabled = false;
21		g.drawImage(this.image, 0, 0, width, height);
22		const {data} = g.getImageData(0, 0, width, height);
23		this.map = [];
24		let row = [];
25		for(let i = 0; i < data.length; i += 4) {
26			const r = data[i];
27			const g = data[i + 1];
28			const b = data[i + 2];
29			const a = data[i + 3];
30			if((i / 4) % width === 0 && Math.floor(i / 4 / width) > 0) {
31				this.map.push(row);
32				row = [];
33			}
34			row.push([r, g, b, a]);
35		}
36		this.map.push(row);
37	}
38	get(x, y) {
39		if(x < 0 || y < 0 || x >= this.width || y >= this.height) {
40			return [];
41		}
42		return this.map[y][x];
43	}