move_predicates.h File Reference

Move validation predicates. More...

#include "scid/core/board.h"
#include <cassert>
#include <utility>

Include dependency graph for move_predicates.h:

Go to the source code of this file.

Functions
bool	scid::core::move_predicates::valid_king (squareT sqFrom, squareT sqTo)
bool	scid::core::move_predicates::valid_knight (squareT sqFrom, squareT sqTo)
int	scid::core::move_predicates::valid_slider (squareT sqFrom, squareT sqTo, pieceT pieceType)
bool	scid::core::move_predicates::attack_pawn (squareT sqFrom, squareT sqTo, colorT pieceCol)
template<typename TFunc >
bool	scid::core::move_predicates::attack_slider (squareT sqFrom, squareT sqTo, pieceT pieceType, TFunc isOccupied)
template<typename TFunc >
bool	scid::core::move_predicates::attack (squareT sqFrom, squareT sqTo, pieceT pieceCol, pieceT pieceType, TFunc isOccupied)
	Validate an ATTACK move, that is if a piece placed at sqFrom can capture an enemy piece at sqTo.
template<typename TFunc >
bool	scid::core::move_predicates::pseudo_advance_pawn (squareT sqFrom, squareT sqTo, colorT pieceCol, TFunc isOccupied)
template<typename TFunc >
bool	scid::core::move_predicates::pseudo (squareT sqFrom, squareT sqTo, colorT pieceCol, pieceT pieceType, TFunc isOccupied)
template<typename TFunc >
std::pair< pieceT, squareT >	scid::core::move_predicates::opens_ray (squareT sqFrom, squareT sqTo, squareT sqRay, TFunc isOccupied)
	Given a pseudo-legal move, this functions return the type and the location of the piece that can possibly pin the moving piece, making the move not legal.
bool	scid::core::move_predicates::blocks_ray (squareT sqFrom, squareT sqTo, squareT sqBlock)
	Checks if there is a valid ray from sqFrom to sqTo and if a piece on sqBlock would block that ray.

Variables
constexpr int	scid::core::move_predicates::NSQUARES = 8
constexpr int	scid::core::move_predicates::kWPHomeRank = 1
constexpr int	scid::core::move_predicates::kBPHomeRank = NSQUARES - 2

Detailed Description

Move validation predicates.

Function Documentation

attack()

template<typename TFunc >

bool scid::core::move_predicates::attack	(	squareT	sqFrom,
		squareT	sqTo,
		pieceT	pieceCol,
		pieceT	pieceType,
		TFunc	isOccupied
	)

Validate an ATTACK move, that is if a piece placed at sqFrom can capture an enemy piece at sqTo.

Parameters

sqFrom	square of the piece.
sqTo	square of the piece to be captured.
pieceCol	color of the moving piece.
pieceType	type of the moving piece.
isOccupied	callable object which should returns true if a square is occupied by a piece. Since it is not invoked with sqFrom or sqTo, it's is irrelevant if the position is the one before or after the move was made.

Returns

true if the move is a valid ATTACK move.

blocks_ray()

bool scid::core::move_predicates::blocks_ray ( squareT  sqFrom, squareT  sqTo, squareT  sqBlock  )

inline

Checks if there is a valid ray from sqFrom to sqTo and if a piece on sqBlock would block that ray.

Parameters

sqFrom	start square of the ray.
sqTo	end square of the ray.
sqBlock	the square that may block the ray.

Returns

true if a piece on sqBlock would block the ray.

opens_ray()

template<typename TFunc >

std::pair< pieceT, squareT > scid::core::move_predicates::opens_ray ( squareT  sqFrom, squareT  sqTo, squareT  sqRay, TFunc  isOccupied  )

inline

Given a pseudo-legal move, this functions return the type and the location of the piece that can possibly pin the moving piece, making the move not legal.

Parameters

sqFrom	start square of the pseudo-legal move.
sqTo	destination square of the pseudo-legal move.
sqRay	the projected ray starts from sqRay and goes through sqFrom; it is usually the square where the king is.
isOccupied	callable object which should returns true if a square is occupied by a piece.

Returns

a std::pair with the type (INVALID_PIECE, BISHOP, ROOK) and the square of the candidate pinning piece. If the type is INVALID_PIECE there is no pin and the move is legal, otherwise it's necessary to test the board position and if the returned square is occupied by an enemy QUEEN, or an enemy piece matching the returned type, the move is not legal.