Basic XP implementation

src/lib/plugins/experience.js

@@ -0,0 +1,106 @@
+module.exports.player = function(player, serv) {
+  player.xp = 0;
+  player.displayXp = 0;
+  player.xpLevel = 0;
+
+  player.sendXp = () => {
+    player._client.write('experience', {
+      experienceBar: player.displayXp,
+      level: player.level,
+      totalExperience: player.xp
+    });
+  }
+
+  player.setXpLevel = (level) => {
+    player.xpLevel = level;
+    player.sendXp();
+  }
+
+  player.setDisplayXp = (num) => {
+    player.displayXp = Math.max(0, Math.min(1, player.displayXp));
+    player.sendXp();
+  }
+
+  player.setXp = (xp, { setLevel=true, setDisplay=true, send=true }={}) => {
+    player.xp = xp;
+    if (setLevel) player.level = serv.getXpLevel(xp);
+    if (setDisplay) player.displayXp = serv.distanceToXpLevel(xp);
+    if (send) player.sendXp();
+  }
+
+  player.commands.add({
+    base: 'xp',
+    info: 'Give yourself experience',
+    usage: '/xp <amount> [player] OR /xp <amount>L [player]',
+    op: true,
+    parse(str) {
+      return str.match(/(-?\d+)(L)? ?([a-zA-Z0-9_]+)?/) || false;
+    },
+    action(args) {
+      var isLevel = !!args[2];
+      var amt = parseInt(args[1]);
+      var user = args[3] ? serv.getPlayer(args[3]) : player;
+      if (!user) return args[3] + ' is not on this server!';
+
+      if (!isLevel) {
+        user.setXp(user.xp + amt);
+        player.chat('Gave ' + user.username + ' ' + amt + ' xp');
+      } else {
+        var currLevel = serv.getXpLevel(player.xp);
+        var baseCurrLevel = serv.getBaseXpFromLevel(currLevel);
+        var extraXp = player.xp - baseCurrLevel;
+        user.setXp(serv.getBaseXpFromLevel(currLevel + amt) + extraXp);
+        player.chat('Gave ' + user.username + ' ' + amt + ' levels');
+      }
+    }
+  });
+}
+
+module.exports.server = function(serv) {
+  serv.distanceToXpLevel = (xp, toLevel) => {
+    var level = serv.getXpLevel(xp);
+    if (!toLevel) toLevel = level+1;
+    var levelBaseXp = serv.getBaseXpFromLevel(level);
+    var requiredXp = serv.getXpRequired(level, toLevel);
+    return (xp - levelBaseXp) / requiredXp;
+  }
+
+  serv.getXpLevel = (xp) => {
+    // I have to use quadratic equation to reverse the equation from serv.getBaseXpFromLevel(). Ugh.
+    var a;
+    var b;
+    var c;
+    if (xp < 352) { // 352 == Experience at level 16
+      a = 1;
+      b = 6;
+      c = 0;
+    } else if (xp < 1507) { // 1507 == Experience at level 31
+      a = 2.5;
+      b = -40.5;
+      c = 360;
+    } else { // Level 32+
+      a = 4.5;
+      b = -162.5;
+      c = 2220;
+    }
+    c -= xp;
+    return Math.floor((-b + Math.sqrt(b*b - 4*a*c)) / (2 * a)); // Math class was useful I guess mmph
+  }
+
+  serv.getXpRequired = (level, toLevel) => {
+    if (!toLevel) toLevel = level + 1;
+    return serv.getBaseXpFromLevel(toLevel) - serv.getBaseXpFromLevel(level);
+  }
+
+  serv.getBaseXpFromLevel = (level) => {
+    // The equations in this function are stupid and directly from the MC Wiki
+    // http://minecraft.gamepedia.com/Experience#Leveling_up
+    if (level <= 16) {
+      return level*level + 6*level;
+    } else if (level <= 31) {
+      return 2.5*level*level - 40.5*level + 360;
+    } else { // 32+
+      return 4.5*level*level - 162.5*level + 2220;
+    }
+  }
+}