SimpleEvalContext Class Reference

Classical, non-neural evaluation context. More...

#include <SimpleEvalContext.h>

Inheritance diagram for SimpleEvalContext:

Collaboration diagram for SimpleEvalContext:

Public Types
using	Score = EvalScore

Public Member Functions
Score	evalOneSide (const Board &board, Color us, int &phase) const
	Evaluates features specific to one side.
void	evalPawns (const Board &board, Color us, const Bitboard &ourPawns, const Bitboard &theirPawns, Score &score) const
	Evaluates pawn structure features.
void	evalKingSafety (const Board &board, Color us, const Bitboard &ourPawns, const Bitboard &theirPawns, Score &score) const
	Evaluates king safety and pawn shield quality.
	SimpleEvalContext ()=default
float	evaluate (const Board &board, int ply=0) override
	Computes the tapered static evaluation of the board.
Public Member Functions inherited from IEvaluator
virtual	~IEvaluator ()=default
virtual WDLConverter::WDL	evaluateWDL (const Board &board, int ply=0)
	Evaluates the board and returns Win/Draw/Loss probabilities.
virtual float	evaluate (const ChessInput &input)
	Evaluates the position using pre-computed features.
virtual void	setAggression (float aggression)
	Sets the contempt or aggression factor for the evaluator.
virtual void	setEvalScale (int base, int weight)
	Sets the scaling parameters for the evaluation score.
virtual void	setEvalNormalization (bool enable)
	Enables or disables dynamic evaluation normalization.
virtual void	setIncrementalRebuildInterval (int interval)
	Sets the interval for forcing full feature rebuilds (to correct accumulation errors).
virtual uint64_t	getFullRebuilds () const
	Retrieves the number of full feature rebuilds performed (for profiling).

Static Public Member Functions
static int	mirror (int sq)
	Mirrors a square index vertically (for black's perspective).

Static Public Attributes
static constexpr int	PHASE_KNIGHT = 1
static constexpr int	PHASE_BISHOP = 1
static constexpr int	PHASE_ROOK = 2
static constexpr int	PHASE_QUEEN = 4
static constexpr int	TOTAL_PHASE = 24
static constexpr int	TEMPO_BONUS = 15
static const Score	PIECE_VALUES [6]
static const Score	PSQT [6][64]
static constexpr Score	BISHOP_PAIR = {30, 80}
static constexpr Score	ROOK_OPEN_FILE = {35, 15}
static constexpr Score	ROOK_SEMI_OPEN = {15, 10}
static constexpr Score	PAWN_PASSED [8]
static constexpr Score	PAWN_ISOLATED = {-10, -15}
static constexpr Score	PAWN_DOUBLED = {-15, -20}

Detailed Description

Classical, non-neural evaluation context.

Implements a traditional evaluation function based on material, PSQT, pawn structure, mobility, and king safety. Useful as a fallback when the neural network is unavailable.

Member Typedef Documentation

Score

using SimpleEvalContext::Score = EvalScore

Constructor & Destructor Documentation

SimpleEvalContext()

SimpleEvalContext::SimpleEvalContext ( )

default

Member Function Documentation

evalKingSafety()

void SimpleEvalContext::evalKingSafety	(	const Board &	board,
		Color	us,
		const Bitboard &	ourPawns,
		const Bitboard &	theirPawns,
		Score &	score ) const

Evaluates king safety and pawn shield quality.

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evalOneSide()

Score SimpleEvalContext::evalOneSide	(	const Board &	board,
		Color	us,
		int &	phase ) const

Evaluates features specific to one side.

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evalPawns()

void SimpleEvalContext::evalPawns	(	const Board &	board,
		Color	us,
		const Bitboard &	ourPawns,
		const Bitboard &	theirPawns,
		Score &	score ) const

Evaluates pawn structure features.

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evaluate()

float SimpleEvalContext::evaluate ( const Board & board, int ply = 0 )

overridevirtual

Computes the tapered static evaluation of the board.

Parameters

board	The chess board position.
ply	Distance from the search root.

Returns

A scalar score from the perspective of the side to move.

Implements IEvaluator.

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mirror()

int SimpleEvalContext::mirror ( int sq )

inlinestatic

Mirrors a square index vertically (for black's perspective).

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Member Data Documentation

BISHOP_PAIR

Score SimpleEvalContext::BISHOP_PAIR = {30, 80}

staticconstexpr

PAWN_DOUBLED

Score SimpleEvalContext::PAWN_DOUBLED = {-15, -20}

staticconstexpr

PAWN_ISOLATED

Score SimpleEvalContext::PAWN_ISOLATED = {-10, -15}

staticconstexpr

PAWN_PASSED

Score SimpleEvalContext::PAWN_PASSED[8]

staticconstexpr

Initial value:

= {{0, 0},     {10, 10}, {10, 20},
      {20, 40},   {40, 80}, {80, 160},
      {150, 250}, {0, 0}}

PHASE_BISHOP

int SimpleEvalContext::PHASE_BISHOP = 1

staticconstexpr

PHASE_KNIGHT

int SimpleEvalContext::PHASE_KNIGHT = 1

staticconstexpr

PHASE_QUEEN

int SimpleEvalContext::PHASE_QUEEN = 4

staticconstexpr

PHASE_ROOK

int SimpleEvalContext::PHASE_ROOK = 2

staticconstexpr

PIECE_VALUES

const SimpleEvalContext::Score SimpleEvalContext::PIECE_VALUES

static

Initial value:

                                                               = {
    {100, 120}, 
    {320, 310}, 
    {330, 320}, 
    {500, 525}, 
    {975, 950}, 
    {0, 0}      
}

PSQT

const SimpleEvalContext::Score SimpleEvalContext::PSQT

static

ROOK_OPEN_FILE

Score SimpleEvalContext::ROOK_OPEN_FILE = {35, 15}

staticconstexpr

ROOK_SEMI_OPEN

Score SimpleEvalContext::ROOK_SEMI_OPEN = {15, 10}

staticconstexpr

TEMPO_BONUS

int SimpleEvalContext::TEMPO_BONUS = 15

staticconstexpr

TOTAL_PHASE

int SimpleEvalContext::TOTAL_PHASE = 24

staticconstexpr

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The documentation for this class was generated from the following files:

• engine/src/eval/SimpleEvalContext.h
• engine/src/eval/SimpleEvalContext.cpp