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This repository contains a C++ and web implementation of the Langton's ant universal Turing machine.

The web version can be found here

Table of contents

• Implementation notes
• Usage
  • Web version
  • C++ version
    • Arguments
      • -x & -y
      • -m
      • -a
      • -i
      • -s
      • -o
      • -t

Implementation notes

Both the C++ (Ant.h) and JavaScript (Ant.js) version share the same implementation concept. There's support for 8 possible operations, which are:

• R45/L45
• R90/L90 (or R/L)
• R135/L135
• C (continue)
• U (180 degree turn)

Usage

Web version

Placeholder

C++ version

Arguments:

-x & -y:

Canvas width/height

-m:

Defines a state machine, can later be used when defining a ant with -a. Can be chained using ;
Example:
-m LRRRRRLLR;RLLLLLRRL: Creates two state machines with index 0 and 1

-a:

Defines ants using the following format P(X,Y)D(DX,DY)M(M)S(S)F(W?) which can be chained using ;

• P Initial position
• D Initial direction
• M Defines which state machine to use, this can be a string (for example RL/R90L90) or a index when using the -m argument
• S Defines the step size
• F Optional section that defines flags (W: Wrap)

Example:
-a P(500,500)D(0,-1)M(RL): Creates a single ant with the state machine RL
-a P(500,500)D(0,-1)M(0)S(10)F(W);P(500,500)D(0,1)M(1): Creates two ants using state machine 0 and 1, ant 0 wraps and has a step size of 10

-i:

Defines how many iterations should be evaluated, by default it will run until all ants run out of bounds or (if wrap is enabled) will run indefinitely. Alternatively t can be added before the number to make it time based.
Example:
-i i50b: Run for 50 billion iterations
-i t100s: Run a maximum of 100 seconds

-s:

Defines when a canvas snapshot should be taken. Can be chained using ;

• i<interval?>: Snapshots every interval iterations (if not specified 1 is assumed)
• f: Snapshots the final state

-o:

Defines how to output images.

• f:<format>:<name>: Write image files. %d can be used for the image index and %i for the current iteration.
• s:<format>:<stdout|stream>:<stream_name?>: Write images to a pipe/stream.
  Supported formats:
• idx: Outputs the raw buffer.
• rgb24: Outputs the raw buffer as RGB24.
• png: Outputs the raw buffer as PNG.

-t:

Defines how many threads should be used, for now this argument only changes the amount of threads used when encoding images, eventually multithreading for the ants will also be added.