Raspberry Pi - Minecraft API - the basics

Anyway, I've been exploring the API which comes with the new Pi edition of Minecraft.  See Raspberry Pi - Minecraft - Install for details on how to install Minecraft: Pi Edition.  If you want a more in-depth tutorial rather than just the basics, see my Minecraft: Pi Edition - API Tutorial post.

http://youtu.be/icrbqilD4Ng

The API works by connecting to the 'server' which maintains the Minecraft world and issuing commands to change the world in real-time.  The api specification is included with the the game, ~/mcpi/api/mcpi_protocol_spec.txt.

The nice people at Mojang, who write Minecraft, also provide class libraries in Java and Python to simplify interactions with the game, which are in the ~/mcpi/api/[java/python] directories.

Create a directory for the program

mkdir ~/minecraft-api

Copy the python class library from minecraft to the programs directory

cp -r ~/mcpi/api/python/mcpi ~/minecraft-api/minecraft

Create minecraft-api.py python program

nano ~/minecraft-api/minecraft-api.py

or open Idle and save minecraft-api.py to the minecraft-api directory

Code

#www.stuffaboutcode.com
#Raspberry Pi, Minecraft API - the basics

#import the minecraft.py module from the minecraft directory

import minecraft.minecraft as minecraft
#import minecraft block module
import minecraft.block as block
#import time, so delays can be used
import time

if __name__ == "__main__":
    
    time.sleep(2)

    #Connect to minecraft by creating the minecraft object
    # - minecraft needs to be running and in a game
    mc = minecraft.Minecraft.create()

    #Post a message to the minecraft chat window
    mc.postToChat("Hi, Minecraft API, the basics, what can you do? ")

    time.sleep(5)

    #Find out your players position

    playerPos = mc.player.getPos()

    mc.postToChat("Find your position - its x=" + str(playerPos.x) + ", y=" + str(playerPos.y) + ", z=" + str(playerPos.z))

    time.sleep(5)

    #Using your players position

    # - the players position is an x,y,z coordinate of floats (e.g. 23.59,12.00,-45.32)

    # - in order to use the players position in other commands we need integers (e.g. 23,12,-45)

    # - so round the players position

    # - the Vec3 object is part of the minecraft class library

    playerPos = minecraft.Vec3(int(playerPos.x), int(playerPos.y), int(playerPos.z))

    #Changing your players position

    mc.postToChat("Move your player - 30 blocks UP!")

    time.sleep(2)

    mc.player.setPos(playerPos.x,playerPos.y + 30,playerPos.z)

    # - wait for you to fall!

    time.sleep(5)

    #Interacting with a block

    # - get the type block directly below you

    blockType =  mc.getBlock(playerPos.x,playerPos.y - 1,playerPos.z)

    mc.postToChat("Interact with blocks - the block below you is of type - " + str(blockType))

    time.sleep(5)

    # - change the block below you to wood planks

    mc.setBlock(playerPos.x,playerPos.y-1,playerPos.z,block.WOOD_PLANKS)

    mc.postToChat("Change blocks - the block below you is now wood planks")

    time.sleep(5)

    #Creating many blocks

    mc.postToChat("Create blocks - making a diamond tower")

    # - loop 20 times

    for up in range(0, 20):

        mc.setBlock(playerPos.x + 1, playerPos.y + up, playerPos.z, block.DIAMOND_BLOCK)

    time.sleep(2)

    # - put you on top of the tower

    mc.postToChat("Dont look down, because Im putting you on top of it!")

    time.sleep(1)

    mc.player.setPos(playerPos.x + 1, playerPos.y + 20, playerPos.z)

    time.sleep(5)

    mc.postToChat("www.stuffaboutcode.com")

The complete code repository is also on github, https://github.com/martinohanlon/minecraft-api.git.

Run 

Note - minecraft must be running and you must be in a game

python ~/minecraft-api/minecraft-api.py

or if using Idle, click Run Module

Performance (on pre-release 0.1)

If you are using the pre-release (version 0.1) of Minecraft you will probably notice that the performance of the API is pretty slow, one of the key reasons for this is that the connection module supplied by mojang, prints the commands sent to the server, which is really useful for debugging but VERY slow - you can turn this off by modifying the connection.py module.

nano ~/minecraft-api/minecraft/connection.py

Change the send function and comment out the 2 print statements, so it looks like this:

    def send(self, f, *data):
        """Sends data. Note that a trailing newline '\n' is added here"""
        s = "%s(%s)\n"%(f, flatten_parameters(data))
        #print "f,data:",f,data
        #print "s",s
        self.drain()
        self.lastSent = s
        self.socket.sendall(s)

Check out my minecraft posts, such as a game of Hide and Seek in Minecraft, an Auto Bridge, no matter where you walk a bridge will always be under your feet or a Massive Analogue Clock, big enough so you can walk on the arms.