add player.changeBlock method, make digging work in creative mode, basic block_place functionality

doc/api.md

@@ -52,6 +52,7 @@
       - [player.login()](#playerlogin)
       - [player.others()](#playerothers)
       - [player.chat(message)](#playerchatmessage)
+      - [player.changeBlock(position,blockType)](#playerchangeblockpositionblocktype)
     - [Low level properties](#low-level-properties)
       - [player._client](#player_client)
     - [Low level methods](#low-level-methods)
@@ -242,6 +243,10 @@ return the other players than `player`
 
 sends `message` to the player
 
+#### player.changeBlock(position,blockType)
+
+change the block at position `position` to `blockType`
+
 ### Low level properties
 
 #### player._client

lib/playerPlugins/blocks.js

@@ -0,0 +1,15 @@
+module.exports=inject;
+
+function inject(serv,player)
+{
+  function changeBlock(position,blockType)
+  {
+    player._writeOthers("block_change",{
+      location:position,
+      type:blockType<<4
+    });
+    serv.world.setBlockType(position.x,position.y,position.z,blockType);
+  }
+
+  player.changeBlock=changeBlock;
+}

lib/playerPlugins/digging.js

@@ -4,13 +4,8 @@ function inject(serv,player)
 {
   // doesn't check whether the player actually wait the correct time
   player._client.on("block_dig",function(packet){
-    if(packet.status==2)
-    {
-      player._writeOthers("block_change",{
-        location:packet.location,
-        type:0
-      });
-      serv.world.setBlockType(packet.location.x,packet.location.y,packet.location.z,0);
-    }
+    if(packet.status==2 || (packet.status==0 && player.gameMode==1))
+      player.changeBlock(packet.location,0);
   });
+
 }

lib/playerPlugins/placeBlock.js

@@ -0,0 +1,16 @@
+var vec3 = require("vec3");
+
+module.exports=inject;
+
+function inject(serv,player)
+{
+  player._client.on("block_place",function(packet){
+    if(packet.direction==-1) return;
+    var referencePosition=new vec3(packet.location.x,packet.location.y,packet.location.z);
+    var directionVector=directionToVector[packet.direction];
+    var placedPosition=referencePosition.plus(directionVector);
+    player.changeBlock(placedPosition,packet.heldItem.blockId);
+  });
+}
+
+var directionToVector=[new vec3(0,-1,0),new vec3(0,1,0),new vec3(0,0,-1),new vec3(0,0,1),new vec3(-1,0,0),new vec3(1,0,0)];