Levev/Chessterm

A terminal based chess interface.

What is it?

Chessterm is a terminal based chess interface.

It was originally created to provide a bridge between several chess engines made by a group of friends to compete with each other.

The current functionality includes:

• Printing the current position of the board
• Moving pieces on the board
• Keeping track of whose turn it is
• Validating any inputted moves
• exporting FEN and PGN of the game
• Detection of checkmate and stalemate

Roadmap

Features that still need to be added

• Add UCI compatability Minimally implemented
• Detect Stalemate
• Detect 3-fold repetition stalemate
• Load/save FEN from/to files
• export/import PGN format
• Flip view of the board between black and white perspective
• Networking

Usage

run $make to compile and start the program with $./chessterm.
The program can be started with the following flags:
-f "fen string between quotes"
to start the board in a given fen position. Fen must be between quotes
-w ./path/to/engine depth
to start the uci compatible engine as the white player with the given computation depth
-b ./path/to/engine depth
to start the uci compatible engine as the black player with the given computation depth
-r ./path/to/engine depth
to start the uci compatible engine as a random player with the given computation depth

All of the above flags can be used interchangibly with each other.

In the program you will be presented with a view of the current position and a prompt. You can type
: exit
to exit the program,
: flip
to switch perspectives between black and white
: autoflip
to switch perspectives between black and white every move
: noflip
to disable autoflip
: fen
to print the current position's FEN to the screen
: pgn
to print the PGN of the game to the screen

: new
to start a new game after one has finished
: go
to allow two engines to play against each other
: thousand
to have two engines play each other 1000 times
: prand
to rate one engine as a percentage of another. Example:
Bad engine equates to Good engine performing at 63.0000%
This output means Bad engine played against Good engine but 37% of Good engine's moves were random.
: status
to view the current board information, or you can type a move in SAN notation to make a move.
Example: : e4 or : Nf3
Pieces must be uppercase, and files must be lowercase for the move to be read correctly.

Implementation Details

Squares on the board will be represented by an array of 64 8-bit unsigned integers. The leading bit will determine the color of the piece on the square.

Empty square = 0

Colors:

Color	Binary	Decimal
white	00000000	0
black	10000000	128

White pieces:

Piece	Binary	Decimal
pawn	00000001	1
bishop	00000010	2
knight	00000100	4
rook	00001000	8
queen	00010000	16
king	00100000	32

Black pieces:

Piece	Binary	Decimal
pawn	10000001	129
bishop	10000010	130
knight	10000100	132
rook	10001000	136
queen	10010000	144
king	10100000	160

Bit-wise OR a piece and a color together to get a colored piece.

The directions a piece can move are described below as relative positions in the array that holds all of the pieces.

-9|-8 |-7
----------
-1| P |+1  
----------  
+7|+8 |+9