Josh-HeapsandClaude Opus 4.8
5345427e0c
- Refactor the search to negamax (single side-relative score + alpha/beta window) - Add a shared, process-wide transposition table: lock-free XOR-verified slots, persists across games, with depth-gated and difficulty-capped score reuse so a weak bot can't borrow a stronger game's deeper analysis - Drive the search with iterative deepening, seeding each depth's move ordering from the previous one - Seed prior-position history (Position::seed_history) over a new engine_best_move history parameter so the engine detects threefold/50-move draws the FEN can't carry Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
86 lines
3.7 KiB
C
86 lines
3.7 KiB
C
/* chess_engine.h - C ABI for a swappable chess engine.
|
|
*
|
|
* Contract: FEN string in, UCI move string out (e.g. "e2e4", "e7e8q").
|
|
* The C# host (CustomChessEngine) owns all buffers. The engine NEVER allocates
|
|
* memory that the host must free. Functions are thread-compatible per-handle only:
|
|
* do NOT call two functions on the SAME handle concurrently. Different handles
|
|
* are independent.
|
|
*/
|
|
#ifndef CHESS_ENGINE_H
|
|
#define CHESS_ENGINE_H
|
|
|
|
#include <stddef.h>
|
|
|
|
/* ---- Export / calling-convention macro (MSVC + GCC/Clang) ---- */
|
|
#if defined(_WIN32)
|
|
#ifdef CHESS_ENGINE_BUILD
|
|
#define CHESS_API __declspec(dllexport)
|
|
#else
|
|
#define CHESS_API __declspec(dllimport)
|
|
#endif
|
|
#define CHESS_CALL __cdecl /* explicit; matches C# CallingConvention.Cdecl */
|
|
#else
|
|
#define CHESS_API __attribute__((visibility("default")))
|
|
#define CHESS_CALL /* SysV default; no decoration needed */
|
|
#endif
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" { /* prevent C++ name mangling */
|
|
#endif
|
|
|
|
/* Opaque handle. The host treats this as a token and never dereferences it.
|
|
* Internally it points to your engine state object. */
|
|
typedef struct ChessEngine* EngineHandle;
|
|
|
|
/* Return codes. 0 == success; negative == error. Keep these values stable. */
|
|
enum {
|
|
CHESS_OK = 0,
|
|
CHESS_ERR_NULL_HANDLE = -1, /* handle was null/invalid */
|
|
CHESS_ERR_BAD_FEN = -2, /* fen failed to parse */
|
|
CHESS_ERR_NO_MOVE = -3, /* no legal move (mate/stalemate) */
|
|
CHESS_ERR_BUFFER = -4, /* out_buf too small for the move + NUL */
|
|
CHESS_ERR_INTERNAL = -5 /* unexpected engine failure */
|
|
};
|
|
|
|
/* Create an engine instance.
|
|
* options: optional null-terminated UTF-8 config string (may be NULL),
|
|
* e.g. "skill=20;hash=256". Parse however you like; ignore for now.
|
|
* returns: a valid EngineHandle, or NULL on allocation failure. */
|
|
CHESS_API EngineHandle CHESS_CALL engine_create(const char* options);
|
|
|
|
/* Set a single option by name (optional; may no-op for now).
|
|
* returns CHESS_OK or a negative code. */
|
|
CHESS_API int CHESS_CALL engine_set_option(EngineHandle engine,
|
|
const char* name,
|
|
const char* value);
|
|
|
|
/* Compute the best move for the given position.
|
|
* engine : handle from engine_create.
|
|
* fen : null-terminated UTF-8 FEN of the position to move from.
|
|
* history : optional null-terminated UTF-8 list of the prior positions since the
|
|
* last irreversible move (capture/pawn move), one FEN per line, oldest
|
|
* first, NOT including `fen`. Lets the engine detect threefold/50-move
|
|
* draws that the FEN alone can't carry. May be NULL or empty.
|
|
* out_buf : host-owned buffer the engine writes the UCI move into,
|
|
* as a null-terminated ASCII string (e.g. "e2e4\0").
|
|
* out_len : capacity of out_buf in bytes (host passes >= 8).
|
|
* returns CHESS_OK on success (out_buf now holds the move), else negative.
|
|
* MUST NOT write more than out_len bytes including the NUL terminator. */
|
|
CHESS_API int CHESS_CALL engine_best_move(EngineHandle engine,
|
|
const char* fen,
|
|
const char* history,
|
|
char* out_buf,
|
|
int out_len);
|
|
|
|
/* Write the engine version string into out_buf (null-terminated).
|
|
* returns CHESS_OK or CHESS_ERR_BUFFER. */
|
|
CHESS_API int CHESS_CALL engine_version(char* out_buf, int out_len);
|
|
|
|
/* Destroy an instance created by engine_create. Safe to call with NULL. */
|
|
CHESS_API void CHESS_CALL engine_destroy(EngineHandle engine);
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
#endif /* CHESS_ENGINE_H */
|