mr-crocs-adventures/js/module.js

import Key from "./Key.js";
import MrCroc from "./MrCroc.js";
import RetroArchitecture from "./retro/RetroArchitecture.js";
import FileLoader from "./FileLoader.js";

class ImageLoader
{
    images = [];
    numberImagesLoaded = 0;

    update()
    {
        this.numberImagesLoaded++;

        if (this.numberImagesLoaded === this.images.length) {
            window.dispatchEvent(new Event('imagesloaded'));
        }
    }

    getCurrentProgress()
    {
        return this.numberImagesLoaded / this.images.length;
    }

    addImage(image)
    {
        image.addEventListener(
            'load', () => {
                this.update();
            }
        );

        this.images.push(image);
    }
}

function MainLoop(timestamp)
{
    if (lastRendered === undefined && lastTimestamp === undefined) {
        lastRendered = timestamp;
        lastTimestamp = timestamp;
    }

    let delta = (timestamp - lastTimestamp) / (10 / GAME_SPEED);

    let ceilingHeight = Math.max(
        architecture.getCeilingHeight(mrCroc.getPositionHeadLeft()),
        architecture.getCeilingHeight(mrCroc.getPositionHeadRight()),
    );

    let groundHeight = Math.min(
        architecture.getGroundHeight(mrCroc.getPositionFootLeft()),
        architecture.getGroundHeight(mrCroc.getPositionFootRight())
    );

    /* Handle falling */
    mrCroc.position.y += mrCroc.fallSpeed;
    mrCroc.fallSpeed += GRAVITY * delta;

    /* Handle ground collision */
    if (mrCroc.position.y > groundHeight && mrCroc.fallSpeed > 0) {
        mrCroc.position.y = groundHeight;
        mrCroc.fallSpeed = 0;
    }

    /* Handle ceiling collision */
    if (mrCroc.position.y - mrCroc.getHeight() <= ceilingHeight) {
        mrCroc.fallSpeed = 0;
        mrCroc.position.y = ceilingHeight + mrCroc.getHeight() + 1;
    }

    /* Handle jumping */
    if (!mrCroc.isJumping && mrCroc.fallSpeed === 0 && mrCroc.position.y === groundHeight && KeyJump.isPressed()) {
        mrCroc.jump();
    } else if (!KeyJump.isPressed()) {
        mrCroc.isJumping = false;
    }

    /* Movement left and right */
    if (KeyLeft.isPressed()) {
        let lastWallLeft = Math.min(
            architecture.getWallLeft(mrCroc.getPositionHeadLeft()),
            architecture.getWallLeft(mrCroc.getPositionFootLeft())
        );

        mrCroc.moveLeft(timestamp, delta);

        if (mrCroc.position.x <= lastWallLeft + mrCroc.getWidth() * 0.5) {
            mrCroc.position.x = lastWallLeft + mrCroc.getWidth() * 0.5 + 1;
        }
    } else if (KeyRight.isPressed()) {
        let lastWallRight = Math.max(
            architecture.getWallRight(mrCroc.getPositionHeadRight()),
            architecture.getWallRight(mrCroc.getPositionFootRight())
        );

        mrCroc.moveRight(timestamp, delta);

        if (mrCroc.position.x >= lastWallRight - mrCroc.getWidth() * 0.5) {
            mrCroc.position.x = lastWallRight - mrCroc.getWidth() * 0.5 - 1;
        }
    }

    /* Drawing */
    if (timestamp - lastRendered >= FRAME_DURATION) {
        context.clearRect(0, 0, window.innerWidth, window.innerHeight);
        architecture.draw(context);
        mrCroc.draw(context);

        /*
        context.fillRect(0, ceilingHeight, window.innerWidth, 1);
        context.fillRect(0, groundHeight, window.innerWidth, 1);
        context.fillStyle = 'black';
        context.fillRect(lastWallRight, 0, 1, window.innerHeight);
        context.fillStyle = 'red';
        context.fillRect(lastWallLeft, 0, 1, window.innerHeight);
        mrCroc.getPositionHeadRight().draw(context);
        mrCroc.getPositionFootRight().draw(context);
        mrCroc.getPositionHeadLeft().draw(context);
        mrCroc.getPositionFootLeft().draw(context);
        */

        lastRendered = timestamp;
    }

    lastTimestamp = timestamp;

    window.requestAnimationFrame(MainLoop);
}

const FPS = 60;
const FRAME_DURATION = 1000 / FPS;
const GAME_SPEED = 1;
const GRAVITY = 2;

let levelJson = new FileLoader('levels/test_startpoint.json');

const LEVEL = JSON.parse(levelJson.getContent());

let lastRendered = undefined;
let lastTimestamp = undefined;
let context;
let mrCroc, architecture;

let KeyLeft = new Key('ArrowLeft');
let KeyRight = new Key('ArrowRight');
let KeyJump = new Key('Space');

let loader = new ImageLoader();

let imgAnimation = new Image();
imgAnimation.src = 'graphics/mr-croc-walk-right.png';
loader.addImage(imgAnimation);

let imgAnimationB = new Image();
imgAnimationB.src = 'graphics/mr-croc-walk-left.png';
loader.addImage(imgAnimationB);

let imgArch = new Image();
imgArch.src = 'graphics/tileset-landscape01.jpg';
loader.addImage(imgArch);

window.addEventListener(
    'imagesloaded',
    () => {
        let canvas = document.getElementById('canvas');
        canvas.width = window.innerWidth;
        canvas.height = window.innerHeight;

        window.addEventListener(
            'resize',
            function () {
                canvas.width = window.innerWidth;
                canvas.height = window.innerHeight;
            }
        );

        context = canvas.getContext('2d');

        architecture = RetroArchitecture.createFromData(LEVEL);

        mrCroc = new MrCroc();
        mrCroc.position.x = architecture.tileWidth * LEVEL.startX + architecture.tileWidth * 0.5;
        mrCroc.position.y = architecture.tileHeight * LEVEL.startY;

        window.requestAnimationFrame(MainLoop);
    }
);