stellar

UCI Chess engine written in C++20
git clone git://git.dimitrijedobrota.com/stellar.git
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commit0f8fcd867fd7ddbae2c118b5639acc0c05e9a2af
parent40ec0f1a8e50396cea47115cda5943fcaa6efbf5
authorDimitrije Dobrota <mail@dimitrijedobrota.com>
dateSat, 5 Aug 2023 15:30:48 +0200

Null Move Pruning

Diffstat:
MCMakeLists.txt|+-
Msrc/engine/engine.c|+++++++++++++

2 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt

@@ -3,7 +3,7 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

project(
Stellar
VERSION 0.0.13
VERSION 0.0.14
DESCRIPTION "Chess engine written in C"
HOMEPAGE_URL https://git.dimitrijedobrota.com/stellar.git
LANGUAGES C

diff --git a/src/engine/engine.c b/src/engine/engine.c

@@ -16,6 +16,7 @@

#define MAX_PLY 64
#define FULL_DEPTH 4
#define REDUCTION_LIMIT 3
#define REDUCTION_MOVE 2
#define INFINITY 50000
#define WINDOW 50

@@ -151,6 +152,18 @@ int negamax(Stats *stats, const Board *board, int alpha, int beta, int depth) {

if (isCheck) depth++;
Board copy;
if (depth >= 3 && !isCheck && stats->ply) {
board_copy(board, &copy);
board_side_switch(&copy);
board_enpassant_set(&copy, no_sq);
int score = -negamax(stats, &copy, -beta, -beta + 2,
depth - 1 - REDUCTION_MOVE);
if (score >= beta) return beta;
}
MoveList list;
move_list_generate(&list, board);