Skip to content

Evaluate piece squares relative to king #232

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
FitzOReilly merged 3 commits into from
Jan 28, 2026
Merged

Evaluate piece squares relative to king #232

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
aecc994
Refactor pawn structure evaluation
FitzOReilly Jan 19, 2026
1358a87
Refactor eval for piece square tables and king tropism
FitzOReilly Jan 27, 2026
09761be
Evaluate piece squares relative to king
FitzOReilly Jan 27, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
489 changes: 244 additions & 245 deletions eval/src/hand_crafted_eval.rs
View file
Open in desktop

Large diffs are not rendered by default.

176 changes: 104 additions & 72 deletions eval/src/hand_crafted_eval_coeffs.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,9 @@ use std::{
};

use movegen::{
file::File,
piece::{self, Piece},
rank::Rank,
side::Side,
square::Square,
};
Expand Down Expand Up @@ -40,7 +42,7 @@ impl From<Score> for Coeff {
}
}

#[derive(Debug, Clone, Default, PartialEq)]
#[derive(Debug, Clone, PartialEq)]
pub struct HandCraftedEvalCoeffs {
pub game_phase: usize,
pub pst_pawn: [Coeff; 32],
Expand All @@ -59,34 +61,56 @@ pub struct HandCraftedEvalCoeffs {
pub rook_mobility: [Coeff; params::ROOK_MOB_LEN],
pub queen_mobility: [Coeff; params::QUEEN_MOB_LEN],
pub bishop_pair: Coeff,
pub distance_friendly_pawn: [Coeff; params::DISTANCE_LEN],
pub distance_enemy_pawn: [Coeff; params::DISTANCE_LEN],
pub distance_friendly_knight: [Coeff; params::DISTANCE_LEN],
pub distance_enemy_knight: [Coeff; params::DISTANCE_LEN],
pub distance_friendly_bishop: [Coeff; params::DISTANCE_LEN],
pub distance_enemy_bishop: [Coeff; params::DISTANCE_LEN],
pub distance_friendly_rook: [Coeff; params::DISTANCE_LEN],
pub distance_enemy_rook: [Coeff; params::DISTANCE_LEN],
pub distance_friendly_queen: [Coeff; params::DISTANCE_LEN],
pub distance_enemy_queen: [Coeff; params::DISTANCE_LEN],
pub distance_friendly_king: [Coeff; params::DISTANCE_LEN],
pub distance_enemy_king: [Coeff; params::DISTANCE_LEN],
pub pawn_square_relative_to_friendly_king: [Coeff; params::SQUARE_RELATIVE_TO_KING_LEN],
pub pawn_square_relative_to_enemy_king: [Coeff; params::SQUARE_RELATIVE_TO_KING_LEN],
pub knight_square_relative_to_friendly_king: [Coeff; params::SQUARE_RELATIVE_TO_KING_LEN],
pub knight_square_relative_to_enemy_king: [Coeff; params::SQUARE_RELATIVE_TO_KING_LEN],
pub bishop_square_relative_to_friendly_king: [Coeff; params::SQUARE_RELATIVE_TO_KING_LEN],
pub bishop_square_relative_to_enemy_king: [Coeff; params::SQUARE_RELATIVE_TO_KING_LEN],
pub rook_square_relative_to_friendly_king: [Coeff; params::SQUARE_RELATIVE_TO_KING_LEN],
pub rook_square_relative_to_enemy_king: [Coeff; params::SQUARE_RELATIVE_TO_KING_LEN],
pub queen_square_relative_to_friendly_king: [Coeff; params::SQUARE_RELATIVE_TO_KING_LEN],
pub queen_square_relative_to_enemy_king: [Coeff; params::SQUARE_RELATIVE_TO_KING_LEN],
}

impl HandCraftedEvalCoeffs {
pub fn add_piece(
&mut self,
p: Piece,
square: Square,
white_king: Square,
black_king: Square,
diff: i8,
) {
self.add_pst(p, square, diff);
self.add_distance(p, square, white_king, black_king, diff);
impl Default for HandCraftedEvalCoeffs {
fn default() -> Self {
Self {
game_phase: Default::default(),
pst_pawn: Default::default(),
pst_knight: Default::default(),
pst_bishop: Default::default(),
pst_rook: Default::default(),
pst_queen: Default::default(),
pst_king: Default::default(),
tempo: Default::default(),
passed_pawn: Default::default(),
isolated_pawn: Default::default(),
backward_pawn: Default::default(),
doubled_pawn: Default::default(),
knight_mobility: Default::default(),
bishop_mobility: Default::default(),
rook_mobility: Default::default(),
queen_mobility: Default::default(),
bishop_pair: Default::default(),
pawn_square_relative_to_friendly_king: [Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN],
pawn_square_relative_to_enemy_king: [Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN],
knight_square_relative_to_friendly_king: [Coeff(0);
params::SQUARE_RELATIVE_TO_KING_LEN],
knight_square_relative_to_enemy_king: [Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN],
bishop_square_relative_to_friendly_king: [Coeff(0);
params::SQUARE_RELATIVE_TO_KING_LEN],
bishop_square_relative_to_enemy_king: [Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN],
rook_square_relative_to_friendly_king: [Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN],
rook_square_relative_to_enemy_king: [Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN],
queen_square_relative_to_friendly_king: [Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN],
queen_square_relative_to_enemy_king: [Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN],
}
}
}

fn add_pst(&mut self, p: Piece, square: Square, diff: i8) {
impl HandCraftedEvalCoeffs {
pub fn add_pst(&mut self, p: Piece, square: Square, diff: i8) {
let pst = match p.piece_type() {
piece::Type::Pawn => &mut self.pst_pawn,
piece::Type::Knight => &mut self.pst_knight,
Expand All @@ -101,63 +125,73 @@ impl HandCraftedEvalCoeffs {
}
}

pub fn clear_distance(&mut self) {
self.distance_friendly_pawn = Default::default();
self.distance_enemy_pawn = Default::default();
self.distance_friendly_knight = Default::default();
self.distance_enemy_knight = Default::default();
self.distance_friendly_bishop = Default::default();
self.distance_enemy_bishop = Default::default();
self.distance_friendly_rook = Default::default();
self.distance_enemy_rook = Default::default();
self.distance_friendly_queen = Default::default();
self.distance_enemy_queen = Default::default();
self.distance_friendly_king = Default::default();
self.distance_enemy_king = Default::default();
pub fn clear_squares_relative_to_king(&mut self) {
self.pawn_square_relative_to_friendly_king =
[Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN];
self.pawn_square_relative_to_enemy_king = [Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN];
self.knight_square_relative_to_friendly_king =
[Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN];
self.knight_square_relative_to_enemy_king = [Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN];
self.bishop_square_relative_to_friendly_king =
[Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN];
self.bishop_square_relative_to_enemy_king = [Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN];
self.rook_square_relative_to_friendly_king =
[Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN];
self.rook_square_relative_to_enemy_king = [Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN];
self.queen_square_relative_to_friendly_king =
[Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN];
self.queen_square_relative_to_enemy_king = [Coeff(0); params::SQUARE_RELATIVE_TO_KING_LEN];
}

pub fn add_distance(
pub fn add_squares_relative_to_king(
&mut self,
p: Piece,
square: Square,
white_king: Square,
black_king: Square,
kings: &[Square; 2],
diff: i8,
) {
let (friendly_dist, enemy_dist) = match p.piece_type() {
let (friendly_square_relative, enemy_square_relative) = match p.piece_type() {
piece::Type::Pawn => (
&mut self.distance_friendly_pawn,
&mut self.distance_enemy_pawn,
&mut self.pawn_square_relative_to_friendly_king,
&mut self.pawn_square_relative_to_enemy_king,
),
piece::Type::Knight => (
&mut self.distance_friendly_knight,
&mut self.distance_enemy_knight,
&mut self.knight_square_relative_to_friendly_king,
&mut self.knight_square_relative_to_enemy_king,
),
piece::Type::Bishop => (
&mut self.distance_friendly_bishop,
&mut self.distance_enemy_bishop,
&mut self.bishop_square_relative_to_friendly_king,
&mut self.bishop_square_relative_to_enemy_king,
),
piece::Type::Rook => (
&mut self.distance_friendly_rook,
&mut self.distance_enemy_rook,
&mut self.rook_square_relative_to_friendly_king,
&mut self.rook_square_relative_to_enemy_king,
),
piece::Type::Queen => (
&mut self.distance_friendly_queen,
&mut self.distance_enemy_queen,
),
piece::Type::King => (
&mut self.distance_friendly_king,
&mut self.distance_enemy_king,
&mut self.queen_square_relative_to_friendly_king,
&mut self.queen_square_relative_to_enemy_king,
),
piece::Type::King => unreachable!(),
};
const OFFSET: i8 = ((Rank::NUM_RANKS - 1) * File::NUM_FILES) as i8;
match p.piece_side() {
Side::White => {
*friendly_dist[square.distance(white_king)] += diff;
*enemy_dist[square.distance(black_king)] -= diff;
*friendly_square_relative
[(OFFSET + square.relative_to(kings[Side::White as usize])) as usize] += diff;
*enemy_square_relative[(OFFSET
+ square
.flip_vertical()
.relative_to(kings[Side::Black as usize].flip_vertical()))
as usize] -= diff;
}
Side::Black => {
*friendly_dist[square.distance(black_king)] -= diff;
*enemy_dist[square.distance(white_king)] += diff;
*friendly_square_relative[(OFFSET
+ square
.flip_vertical()
.relative_to(kings[Side::Black as usize].flip_vertical()))
as usize] -= diff;
*enemy_square_relative
[(OFFSET + square.relative_to(kings[Side::White as usize])) as usize] += diff;
}
}
}
Expand All @@ -180,17 +214,15 @@ impl HandCraftedEvalCoeffs {
.chain(self.rook_mobility.iter())
.chain(self.queen_mobility.iter())
.chain(iter::once(&self.bishop_pair))
.chain(self.distance_friendly_pawn.iter())
.chain(self.distance_enemy_pawn.iter())
.chain(self.distance_friendly_knight.iter())
.chain(self.distance_enemy_knight.iter())
.chain(self.distance_friendly_bishop.iter())
.chain(self.distance_enemy_bishop.iter())
.chain(self.distance_friendly_rook.iter())
.chain(self.distance_enemy_rook.iter())
.chain(self.distance_friendly_queen.iter())
.chain(self.distance_enemy_queen.iter())
.chain(self.distance_friendly_king.iter())
.chain(self.distance_enemy_king.iter())
.chain(self.pawn_square_relative_to_friendly_king.iter())
.chain(self.pawn_square_relative_to_enemy_king.iter())
.chain(self.knight_square_relative_to_friendly_king.iter())
.chain(self.knight_square_relative_to_enemy_king.iter())
.chain(self.bishop_square_relative_to_friendly_king.iter())
.chain(self.bishop_square_relative_to_enemy_king.iter())
.chain(self.rook_square_relative_to_friendly_king.iter())
.chain(self.rook_square_relative_to_enemy_king.iter())
.chain(self.queen_square_relative_to_friendly_king.iter())
.chain(self.queen_square_relative_to_enemy_king.iter())
}
}
1 change: 1 addition & 0 deletions eval/src/lib.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -15,3 +15,4 @@ pub mod score;
pub mod score_pair;

mod game_phase;
mod piece_table_refs;
Loading