User:Sulai7200/Ideas/Scripting

This webpage is about how to implement scripting in minecraft. Scripting should allow both scripting blocks, items and monsters (NPC), and the server admins to change the served world.

Game content is defined through blocks, items and monsters. Those three types of content should be scriptable. Scripts of such game content are text files stored in a file system like that:

 default package
   creeper
     script.js
   redstone block
     script.js
   redstone dust item
     script.js
 
 cool user extension from sulai
   elevator
   catapult
   books with some interesting content

 action pack from CompanionCube
   chaos gun
   ammo

Each level-2 subfolder contains a script.js (as shown in the default package). This script defines the behavior of blocks, items and monsters. More content may be downloaded from various websites. When the server starts up, the server admin may choose, what user extensions packs he wants to allow on his world:

[x]  default package (Mojang)
[ ]  cool user extension from sulai 
[x]  action pack from CompanionCube

On startup, those scripted definitions are loaded into the game. If clients connect to that server, not only the world map, but also the scriped definitions are downloaded. If CompanionCube's ammo is defined to be produced by some recipe, any user connected to that server may now produce ammo.

Of course if those scripted components are downloaded from the server, security is most important. We don't want a server that would crash the game because of some bad code. I propose to use Mozzilla's Rhino JavaScript, which lets the java programmer [ http://www.docjar.com/docs/api/org/mozilla/javascript/ClassShutter.html restrict script access to a blacklist of java methods].

Script Examples

This is what a server admin needs to type into console if he wants to place a monster:

 createMonster("creeper", 20, 10);

This is what a server admin needs to do if he wants to create a 40x40 platform around the spawn point:

 createBlockRect("sand stone", -20, -20, 20, 20);

This is a NPC salesman who sells redstone for some coal and flees from foes.

 getType() {
   return "monster";
 }

 // if hit, run away
 function onHit() {
   message("ouch!");
   setDestiny( rnd(40)-20 , rnd(40)-20 );
 }
 
 function onCollect(obj) {
 
   // if moving, stop
   setDestiny(0,0);
 
   // player throws coal at NPC: do the deal
   if( obj.getName()=="coal" ) {
     message("thanks man!");
     throw(createObject("redstone dust"));
   }

   // player throws something else: give it back
   else {
     message("I only deal with coal");
     throw(obj);
   }
 
 }

This is redstone written in script:

 function getType() {
   return "block";
 }

 function getName() {
    return "redstone";
 }

 function getHardness() {
   return 10000;
 }

 function init() {
   setTexture("redstone.png")
 }
 
 function onHit() {
   setEmitedLight(10);
 }

 function onBreak() {
   spawn("redstone dust", 4);
 }

This is redstone dust written in script:

 function getType(){
   return "object";
 }

 function getName() {
   return "redstone dust";
 }

 function getRecipe() {
   return null
 }
 
 function init() {
   setTexture("redstone dust.png");
 }

 function onPut(x,y,z) {
   put("redstone wire", x, y, z);
   removeObject(this);
 }