game.js

import {Entity, Room} from "../../../hampsterengine/src/things";
import Player from "../objects/player";
import {clone, clonePlayer, abs} from "../extras";
import Ground from "../objects/ground";

export const rm_game = new Room();
const GRAVITY_X = 0; // I don't think we're going to use X gravity but i'm going to keep in the source in case i do
const GRAVITY_Y = 300; // Per second
const entities = rm_game.entities;

rm_game.width = 1000;
rm_game.height = 1000;

rm_game.start = _=>{
    engine.running = true;
}

rm_game.stop = _=>{
    engine.running = false;
}

rm_game.step = _=>{
    const elapsed = 1 / 60;
    const player = rm_game.get('plr');

    let friction = 0.9;
    const boost = keyboard.keys.includes("Shift") ? 40 : 0;

    for (const key of keyboard.keys) {
        switch (key) {
            case "ArrowLeft":
                player.vx = -80-boost;
                break;
            case "ArrowRight":
                player.vx = 80+boost;
                break;
            case " ":
                if (!player.jumping) {
                    player.jumping = true;
                    player.vy -= 150;
                }
        }
    }

    const entitiesWithoutThePlayer = [...entities].toSpliced(entities.indexOf(player), 1);
    // console.debug(entitiesWithoutThePlayer);

    player.vx = Math.min(500, player.vx + (player.ax * elapsed + GRAVITY_X*elapsed));
    player.vy = Math.min(500, player.vy + (player.ay * elapsed + GRAVITY_Y*elapsed));
    player.x += player.vx * elapsed;
    player.y += player.vy * elapsed;

    // Make acceleration decay
    player.ax *= 0.1;
    player.ay *= 0.1;

    if (abs(player.ax) < 0.01) player.ax = 0;
    if (abs(player.ay) < 0.01) player.ay = 0;

    rm_game.x = player.x;
    rm_game.y = player.y;

    for (const entity of entitiesWithoutThePlayer) {
        if (player.checkCollision(entity)) {
            friction = 0.8;
            let side = player.resolveCollision(entity);
            if (side === 2) player.jumping = 0;
            if (side === 1 || side === 3) friction = 0.5;
        }