Merge pull request #23 from nickpoorman/master

Added falling damage

.gitignore

@@ -1,3 +1,4 @@
 /node_modules
 /config.json
 /map
+/server.js

lib/game.js

@@ -5,6 +5,7 @@ var Map = require("./map");
 
 var Game = module.exports = function Game(config) {
   events.EventEmitter.call(this);
+  this.setMaxListeners(0);
 
   if (!config) {
     config = {};

lib/player.js

@@ -13,6 +13,10 @@ var Player = module.exports = function Player(game, options) {
   this.stance = 0;
   this.on_ground = 1;
 
+  this.health = 20;
+  this.food = 20;
+  this.saturation = 5;
+
   if (typeof this.options.stance    === "number") { this.stance    = this.options.stance;    }
   if (typeof this.options.on_ground === "number") { this.on_ground = this.options.on_ground; }
 };

plugins/player-abilities.js

@@ -0,0 +1,27 @@
+/**
+  Player abilities plugin.
+  This is used to keep track of player ability state between the client and the server.
+  Handles 0xCA in protocol.
+*/
+module.exports = function() {
+  return function(game) {
+    game.on("player:join", function(player) {
+      player.client.on("packet:ca", function(packet) {
+
+        var creativeMode = (packet.flags & 0x01);
+        var flying = (packet.flags & 0x02) >> 1;
+        var canFly = (packet.flags & 0x04) >> 2;
+        var invulnerable = (packet.flags & 0x08) >> 3;
+
+        if(player.mode != creativeMode) {
+          // something weird is happening here, lets log it
+          console.warn('[Warning] Player client side game mode does not match server side!');
+        }
+
+        player.flying = flying;
+        // trigger an event here to notify any plugins listening for flying status
+        player.emit("flying", flying);
+      });
+    });
+  };
+};

plugins/player-fall.js

@@ -0,0 +1,76 @@
+/**
+  Fall plugin.
+  When a user falls apply the damage to their health.
+  This is by no means complete. Just having some fun playing with node and minecraft.
+  Also, this doesn't yet take into consideration velocity, and falling into water.
+
+  This might need to be loaded after player-abilities plugin.
+*/
+module.exports = function() {
+  return function(game) {
+    game.on("player:join", function(player) {
+      player.client.on("packet:0a", on_fall.bind(player, game));
+      player.client.on("packet:0b", on_fall.bind(player, game));
+      player.client.on("packet:0c", on_fall.bind(player, game));
+      player.client.on("packet:0d", on_fall.bind(player, game));
+      player.on("flying", handle_falling_pos.bind(player));
+    });
+  };
+};
+
+var set_falling_pos = function set_falling_pos(player) {
+    player.start_falling_pos = player.y;
+  }
+
+var handle_falling_pos = function handle_falling_pos(flying) {
+    // if the player stops flying
+    if(!flying) set_falling_pos(this);
+  }
+
+var on_fall = function on_fall(game, packet) {
+    // Need the block type to determine if the player is swimming.
+    // Maybe there is a better way to do this? ...swimming/flying should probably be kept track of in player.js with movement.js
+    var x = packet.x || this.x,
+      z = packet.z || this.z,
+      y = packet.y || this.y;
+
+    var block_x = x & 0x0f,
+      block_z = z & 0x0f,
+      block_y = y;
+
+    var WATER = 8;
+    var STATIONARY_WATER = 9;
+
+    game.map.get_abs_chunk(x, z, function(err, chunk) {
+      var blockType = chunk.get_block_type(block_x, block_z, block_y);
+      var swimming = blockType == STATIONARY_WATER || blockType == WATER;
+
+      // try to guess if they are flying to begin with
+      // if the block below them is air then they are probably flying
+      // this is untested - might need to find a way to do this with the protocol
+      if(typeof this.flying == "undefined") {
+        this.flying = chunk.get_block_type(block_x, block_z, block_y - 1) == 0;
+      }
+
+      // don't apply fall if they are swimming
+      if(!swimming) {
+        // when on_ground changes from true to false start keeping track of distance
+        if(this.on_ground && !packet["on_ground"]) {
+          set_falling_pos(this);
+        }
+        // Edge case:
+        // also when flying changes from true to false we need to set the height
+        // - this will get handled when the "flying",false event fires
+
+        // when it changes from false to true then calculate damage
+        if(!this.on_ground && packet["on_ground"]) {
+          var damage = Math.floor(this.start_falling_pos - packet.y - 3);
+          //trigger a damage event on the player
+          if(damage > 0) this.emit("damage", damage);
+
+          //TODO?: emit sound 0x3e
+        }
+      }
+
+    }.bind(this));
+  };

plugins/player-health.js

@@ -0,0 +1,32 @@
+module.exports = function() {
+  return function(game) {
+    game.on("player:join", function(player) {
+      player.on("damage", on_damage.bind(player));
+
+      // defaults
+      player.damaged = 0;
+    });
+
+    game.on("tick", update_health.bind(null, game));
+  };
+};
+
+var on_damage = function on_damage(damage) {
+    //set the damage to the player if they aren't on creative mode, so 0 or 2
+    if(this.mode != 1) {
+      this.damaged += damage;
+    }
+  };
+
+var update_health = function update_health(game) {
+    game.players.filter(function(e) {
+      return e.damaged > 0;
+    }).forEach(function(player) {
+      // modify the players health to match the damage done
+      player.health -= player.damaged;
+      // send out necessary packet to update the health
+      player.health < 0 ? player.kill() : player.setHealth(player.health, player.food, player.saturation);
+      // reset the damage done
+      player.damaged = 0;
+    });
+  };

server.example.js

@@ -150,6 +150,18 @@ game.use(SaveMapPlugin(__dirname + "/map"));
 var AdminPlugin = require('./plugins/admin');
 game.use(AdminPlugin());
 
+// This is used to keep track of player ability state between the client and the server
+var PlayerAbilitiesPlugin = require('./plugins/player-abilities');
+game.use(PlayerAbilitiesPlugin());
+
+// This plugin manages players health & hunger
+var PlayerHealthPlugin = require('./plugins/player-health');
+game.use(PlayerHealthPlugin());
+
+// This plugin controlls falling damage/death
+var PlayerFallPlugin = require('./plugins/player-fall');
+game.use(PlayerFallPlugin());
+
 // The server object is basically a wrapper around `net.Server` that constructs
 // `Client` objects as they connect.