multiplayer-canvas/server/core.js

var glob = require('glob'),
fs = require('fs'),
crypto = require('crypto');

commands = require('./commands');

session = {};

class Core {
	constructor() {
		this.timerId = -1;
		this.lastTime = 0;
	}

	load() {
		session.players = [];
		session.playerIndex = 1;

		if(this.timerId != -1 ) {
			clearInterval(this.timerId);
		}

		this.lastTime = new Date().getTime();
		//todo: populate rooms

		this.timerId = setInterval(function() {
			core.tick(new Date().getTime());

		}, 250);
	}

	handleInput(player, input) {
		var action = input.action;
		for(var commanderClass in commands) {
			var commander = new commands[commanderClass]();
			if (typeof commander[action] == 'function') {
				try {
					if(commander[action](player, input)) {
						return true;
					}
				} catch (error) {
					console.error("Exception in command " + commanderClass, error, error.stack);
				}
			}	
		}

		throw new Error("Unhandled Command");
		return true;
	}

	tick(time) {
		var delta = this.getUpdateRate(this.lastTime, time);
		this.lastTime = time;
		try {
			//loop over tick-able items
			for(var i in session.players) {
				var player = session.players[i];
				if(player == null) {
					continue;
				}
				player.update(delta);
			}
		} catch (error) {
			console.error("Tick error", error, error.stack);
		}
	}

	sendUpdateToAll(sender) {
		for(var i in session.players) {
			var player = session.players[i];
			if(player == null) {
				continue;
			}
			player.sendUpdate(sender);
		}
		
	}

	sendToAll(data) {
		for(var i in session.players) {
			var player = session.players[i];
			if(player == null) {
				continue;
			}
			player.sendMessage(data);
		}
		
	}

	getUpdateRate(start, stop) {
		return (stop - start) / 16;
	}

	getColor() {
		var colors = [
		"#DD3333",
		"#DDDD33",
		"#33DD33",
		"#33DDDD",
		"#3333DD",
		"#333333",
		];
		return colors[parseInt(Math.random() * colors.length)];
	}

	attachPlayer(player) {
		player.id = session.playerIndex++;
		player.shipColor = this.getColor();
		player.playerName = "Player " + player.id;

		
		
		for(var i in session.players) {
			var other = session.players[i];
			if(other == null) {
				continue;
			}
			player.sendUpdate(other);
		}
		session.players[player.id] = player;
		core.sendUpdateToAll(player);
	}

	removePlayer(player) {
		session.players[session.players.indexOf(player)] = null;
		core.sendToAll({"remove": player.id});
	}

	rollRandom(probabilitySet) {
		var rollValue = parseInt(Math.random() * 100) + 1;
		var probabilityTotal = 0;
		var sortedSet = probabilitySet.sort(function(a, b) {
			return (a.probability < b.probability) ? 1 : ((a.probability > b.probability) ? -1 : 0);
		});
		for(var index in sortedSet) {
			var row = sortedSet[index];
			probabilityTotal += row.probability;
			if(rollValue <= probabilityTotal) {
				return row.value;
			}
		}
	}
}

module.exports = new Core();