====== Chess - Programming - Polyglot Book Format - Piece ======

**Piece** is part of the [[Chess:Programming:Polyglot Book Format:Key|Key]].

It is the exclusive or of entries from the **RANDOM_PIECE** sub-array, one for each piece on the board.

The offset of the entry in **RANDOM_PIECE** corresponding to a piece is computed as follows: <code>
piece = 64 * Piece_Type + 8 * Rank + File;
</code>

----

**Piece_Type** is encoded as:

<code cpp>
  constexpr int BlackPawn   = 0;
  constexpr int WhitePawn   = 1;
  constexpr int BlackKnight = 2;
  constexpr int WhiteKnight = 3;
  constexpr int BlackBishop = 4;
  constexpr int WhiteBishop = 5;
  constexpr int BlackRook   = 6;
  constexpr int WhitekRook  = 7;
  constexpr int BlackQueen  = 8;
  constexpr int WhiteQueen  = 9;
  constexpr int BlackKing   = 10;
  constexpr int WhiteKing   = 11;
  constexpr int None        = 12;
</code>

----

**Rank** and **File** are counted from 0 to 7:

^Square^File^Rank^
|a1|0|0|
|h1|7|0|
|a8|0|7|
|h8|7|7|

----

[[Chess:Programming:Polyglot Book Format:Piece|Piece]]