game-engine/modules/game-objects/map.js

59 lines
1.5 KiB
JavaScript

import { COLS, ROWS, TILE_SIZE } from "../constants.js";
import { createCanvas } from "../utils.js";
import { GameObject } from "./game-object.js";
export class Map extends GameObject {
constructor({ name, imageId, elementId, selected = false }) {
super();
this.name = name;
this.imageId = imageId;
this.image = document.getElementById(imageId);
this.width = this.image.width;
this.selected = selected;
this.elementId = elementId;
}
async load() {
const levelConfig = await fetch("/resources/" + this.name + ".json");
this.levelConfig = await levelConfig.json();
}
get level() {
if (this._level) {
return this._level;
}
const { ctx, canvas } = createCanvas(COLS * TILE_SIZE, ROWS * TILE_SIZE);
const image = this.image;
const width = this.width;
const level = this.levelConfig;
const layer = level.layers[0];
const data = layer.data;
for (let row = 0; row < ROWS; row++) {
for (let col = 0; col < COLS; col++) {
const tile = data[row * COLS + col] - 1;
ctx.drawImage(
image,
(tile * TILE_SIZE) % width,
Math.floor((tile * TILE_SIZE) / width) * TILE_SIZE,
TILE_SIZE,
TILE_SIZE,
col * TILE_SIZE,
row * TILE_SIZE,
TILE_SIZE,
TILE_SIZE
);
}
}
return (this._level = canvas);
}
render(ctx) {
if (!this.levelConfig || !this.selected) {
return;
}
ctx.drawImage(this.level, 0, 0);
}
}