papercats/paper-io-bot.js

if (process.argv.length < 3) {
	console.log("Usage: node paper-io-bot.js <socket-url> [<name>]")
	process.exit(1);
}

var core = require("./src/core");
var client = require("./src/game-client");
var { consts } = require("./config.json");

var MOVES = [[-1, 0], [0, 1], [1, 0], [0, -1]];

var startFrame = -1;
var endFrame = -1;
var grid, others, user, playerPortion = {}, claim = [];

function mod(x) {
	x %= 4;
	if (x < 0) x += 4;
	return x;
}

function connect() {
	var prefixes = consts.PREFIXES.split(" ");
	var names = consts.NAMES.split(" ");
	var name = process.argv[3] || [prefixes[Math.floor(Math.random() * prefixes.length)], names[Math.floor(Math.random() * names.length)]].join(" ");
	client.connectGame(process.argv[2], "[BOT] " + name, function(success, msg) {
		if (!success) {
			console.error(msg);
			setTimeout(connect, 1000);
		}
	});
}

function Loc(row, col) {
	if (this.constructor != Loc) return new Loc(row, col);

	this.row = row;
	this.col = col;
}

function update(frame) {
	if (startFrame == -1) startFrame = frame;
	endFrame = frame;

	if (frame % 6 == (startFrame + 1) % 6) {
		grid = client.grid;
		others = client.getOthers();

		//Note: the code below isn't really my own code. This code is in fact the
		//approximate algorithm used by the paper.io game. It has been modified from
		//the original code (i.e. deobfuscating) and made more efficient in some
		//areas (and some tweaks), otherwise, the original logic is about the same.
		var row = user.row, col = user.col, dir = user.currentHeading;
		var thres = (.05 + .1 * Math.random()) * consts.GRID_COUNT * consts.GRID_COUNT;

		if (row < 0 || col < 0 || row >= consts.GRID_COUNT || col >= consts.GRID_COUNT) return;

		if (grid.get(row, col) === user) {
			//When we are inside our territory
			claim = [];
			weights = [25, 25, 25, 25];
			weights[dir] = 100;
			weights[mod(dir + 2)] = -9999;

			for (var nd = 0; nd < 4; nd++) {
				for (var S = 1; S < 20; S++) {
					var nr = MOVES[nd][0] * S + row;
					var nc = MOVES[nd][1] * S + col;

					if (nr < 0 || nc < 0 || nr >= consts.GRID_COUNT || nc >= consts.GRID_COUNT) {
						if (S > 1) weights[nd]--;
						else weights[nd] = -9999;
					}
					else {
						if (grid.get(nr, nc) !== user) weights[nd]--;

						var tailed = undefined;
						for (var o of others) {
							if (o.tail.hitsTail(new Loc(nr, nc))) {
								tailed = o;
								break;
							}
						}

						if (tailed) {
							if (o.name.indexOf("PAPER") != -1) weights[nd] += 3 * (30 - S); //Don't really try to kill our own kind
							else weights[nd] += 30 * (30 - S);
						}
					}
				}
			}

			//View a selection of choices based on the weights we computed
			var choices = [];
			for (var d = 0; d < 4; d++) {
				for (var S = 1; S < weights[d]; S++) {
					choices.push(d);
				}
			}

			if (choices.length === 0) choices.push(dir);
			dir = choices[Math.floor(Math.random() * choices.length)];
		}
		else if (playerPortion[user.num] < thres) {
			//Claim some land if we are relatively tiny and have little to risk.
			if (claim.length === 0) {
				var breadth = 4 * Math.random() + 2;
				var length = 4 * Math.random() + 2;
				var ccw = 2 * Math.floor(2 * Math.random()) - 1;

				turns = [dir, mod(dir + ccw), mod(dir + ccw * 2), mod(dir + ccw * 3)];
				lengths = [breadth, length, breadth + 2 * Math.random() + 1, length];

				for (var i = 0; i < turns.length; i++) {
					for (var j = 0; j < lengths[i]; j++) {
						claim.push(turns[i]);
					}
				}
			}

			if (claim.length !== 0) dir = claim.shift();
		}
		else {
			claim = [];
			//We are playing a little bit more cautious when we are outside and have a
			//lot of land
			weights = [5, 5, 5, 5];
			weights[dir] = 50;
			weights[mod(dir + 2)] = -9999;

			for (var nd = 0; nd < 4; nd++) {
				for (var S = 1; S < 20; S++) {
					var nr = MOVES[nd][0] * S + row;
					var nc = MOVES[nd][1] * S + col;

					if (nr < 0 || nc < 0 || nr >= consts.GRID_COUNT || nc >= consts.GRID_COUNT) {
						if (S > 1) weights[nd]--;
						else weights[nd] = -9999;
					}
					else {
						if (user.tail.hitsTail(new Loc(nr, nc))) {
							if (S > 1) weights[nd] -= 50 - S;
							else weights[nd] = -9999;
						}

						if (grid.get(nr, nc) === user) weights[nd] += 10 + S;

						var tailed = undefined;
						for (var o of others) {
							if (o.tail.hitsTail(new Loc(nr, nc))) {
								tailed = o;
								break;
							}
						}

						if (tailed) {
							if (o.name.indexOf("PAPER") != -1) weights[nd] += 3 * (30 - S); //Don't really try to kill our own kind
							else weights[nd] += 30 * (30 - S);
						}
					}
				}
			}

			//View a selection of choices based on the weights we computed
			var choices = [];
			for (var d = 0; d < 4; d++) {
				for (var S = 1; S < weights[d]; S++) {
					choices.push(d);
				}
			}

			if (choices.length === 0) choices.push(dir);
			dir = choices[Math.floor(Math.random() * choices.length)];
		}
		client.changeHeading(dir);
	}
}

function calcFavorability(params) {
	return params.portion + params.kills * 50 + params.survival / 100;
}

client.allowAnimation = false;
client.renderer = {
	addPlayer: function(player) {
		playerPortion[player.num] = 0;
	},
	disconnect: function() {
		var dt = (endFrame - startFrame);
		startFrame = -1;

		console.log(`[${new Date()}] I died... (survived for ${dt} frames.)`);
		console.log(`[${new Date()}] I killed ${client.kills} player(s).`);
		setTimeout(connect, 5000);
	},
	removePlayer: function(player) {
		delete playerPortion[player.num];
	},
	setUser: function(u) {
		user = u;
	},
	update: update,
	updateGrid: function(row, col, before, after) {
		before && playerPortion[before.num]--;
		after && playerPortion[after.num]++;
	}
};

connect();