game-engine/index.js

111 lines
3.1 KiB
JavaScript

import { CanvasResizer } from "./modules/canvas-resizer.js";
import { getLevel } from "./modules/utils.js";
const TILE_SIZE = 16;
const canvasResizer = new CanvasResizer({
canvas: document.getElementById("game"),
width: 320 / 2,
height: 240 / 2,
percentage: 0.9,
});
const cols = canvasResizer.width / TILE_SIZE;
const rows = canvasResizer.height / TILE_SIZE;
const ctx = canvasResizer.canvas.getContext("2d");
let debug = false;
let cameraX = 0;
let cameraY = 0;
async function drawLevel({ levelName, imageName }) {
const levelImage = document.getElementById(imageName);
const level = await getLevel(levelName);
const layer = level.layers[0];
const { data, width, height } = layer; // Obtenemos la capa del tilemap, con su numero de columnas y filas
const endCol = cameraX + cols;
const endRow = cameraY + rows;
for (let row = cameraY; row <= endRow; row++) {
for (let col = cameraX; col <= endCol; col++) {
if (row < 0 || col < 0 || row >= height || col >= width) continue; // Omitimos tiles fuera del rango del tilemap
if (debug) {
ctx.strokeRect(
(col - cameraX) * TILE_SIZE,
(row - cameraY) * TILE_SIZE,
TILE_SIZE,
TILE_SIZE
);
}
const tile = data[row * width + col];
ctx.drawImage(
levelImage,
((tile - 1) * TILE_SIZE) % levelImage.width,
Math.floor(((tile - 1) * TILE_SIZE) / levelImage.width) * TILE_SIZE,
TILE_SIZE,
TILE_SIZE,
(col - cameraX) * TILE_SIZE,
(row - cameraY) * TILE_SIZE,
TILE_SIZE,
TILE_SIZE
);
}
}
}
function moveCamera(dx, dy) {
cameraX = Math.min(
Math.max(cameraX + dx, 0),
Math.floor((320 - canvasResizer.width) / TILE_SIZE)
);
cameraY = Math.min(
Math.max(cameraY + dy, 0),
Math.floor((240 - canvasResizer.height) / TILE_SIZE)
);
}
async function run() {
await canvasResizer.load();
let selectedLevel = { levelName: "overworld", imageName: "overworld" };
const debugButton = document.getElementById("debug");
debugButton.addEventListener("click", async () => {
debug = !debug;
await drawLevel(selectedLevel);
});
const level1Button = document.getElementById("level1");
level1Button.addEventListener("click", async () => {
selectedLevel = { levelName: "overworld", imageName: "overworld" };
await drawLevel(selectedLevel);
});
const level2Button = document.getElementById("level2");
level2Button.addEventListener("click", async () => {
selectedLevel = { levelName: "ocean", imageName: "overworld" };
await drawLevel(selectedLevel);
});
window.addEventListener("keydown", (event) => {
switch (event.key) {
case "ArrowUp":
moveCamera(0, -1);
break;
case "ArrowDown":
moveCamera(0, 1);
break;
case "ArrowLeft":
moveCamera(-1, 0);
break;
case "ArrowRight":
moveCamera(1, 0);
break;
}
drawLevel(selectedLevel);
});
await drawLevel(selectedLevel);
}
run();