From e8f31beb70d0574b7c402f50009fc01643b463e6 Mon Sep 17 00:00:00 2001 From: Jeremy O'Brien Date: Tue, 17 Sep 2024 22:36:34 -0400 Subject: [PATCH] Smallchess face (#272) * smallchess face * use correct game-state modifying board move function * make show last work after undo * use SCL_Game->ply instead of board[ply_byte] * beep when cpu is done computing a move * increase engine strength to ply 3 * match ply type and use the local variable where available * fix warnings * add doc to smallchess face * smallchess: fix compile warnings * smallchess: move smallchesslib.h to movement/lib --- movement/lib/smallchesslib/smallchesslib.h | 3704 +++++++++++++++++ movement/make/Makefile | 2 + movement/movement_faces.h | 1 + .../complication/smallchess_face.c | 504 +++ .../complication/smallchess_face.h | 90 + 5 files changed, 4301 insertions(+) create mode 100644 movement/lib/smallchesslib/smallchesslib.h create mode 100644 movement/watch_faces/complication/smallchess_face.c create mode 100644 movement/watch_faces/complication/smallchess_face.h diff --git a/movement/lib/smallchesslib/smallchesslib.h b/movement/lib/smallchesslib/smallchesslib.h new file mode 100644 index 0000000..7ac8542 --- /dev/null +++ b/movement/lib/smallchesslib/smallchesslib.h @@ -0,0 +1,3704 @@ +#ifndef SMALLCHESSLIB_H +#define SMALLCHESSLIB_H + +/** + @file smallchesslib.h + + Small and simple single header C99 public domain chess library and engine. + + author: Miloslav Ciz (drummyfish) + license: CC0 1.0 (public domain) + found at https://creativecommons.org/publicdomain/zero/1.0/ + + additional waiver of all IP + version: 0.8d + + Default notation format for this library is a coordinate one, i.e. + + squarefrom squareto [promotedpiece] + + e.g.: e2e4 or A2A1q + + This work's goal is to never be encumbered by any exclusive intellectual + property rights. The work is therefore provided under CC0 1.0 + additional + WAIVER OF ALL INTELLECTUAL PROPERTY RIGHTS that waives the rest of + intellectual property rights not already waived by CC0 1.0. The WAIVER OF ALL + INTELLECTUAL PROPERTY RGHTS is as follows: + + Each contributor to this work agrees that they waive any exclusive rights, + including but not limited to copyright, patents, trademark, trade dress, + industrial design, plant varieties and trade secrets, to any and all ideas, + concepts, processes, discoveries, improvements and inventions conceived, + discovered, made, designed, researched or developed by the contributor either + solely or jointly with others, which relate to this work or result from this + work. Should any waiver of such right be judged legally invalid or + ineffective under applicable law, the contributor hereby grants to each + affected person a royalty-free, non transferable, non sublicensable, non + exclusive, irrevocable and unconditional license to this right. +*/ + +#include + +#ifndef SCL_DEBUG_AI +/** AI will print out a Newick-like tree of searched moves. */ + #define SCL_DEBUG_AI 0 +#endif + +/** + Maximum number of moves a chess piece can have (a queen in the middle of the + board). +*/ +#define SCL_CHESS_PIECE_MAX_MOVES 25 +#define SCL_BOARD_SQUARES 64 + +typedef uint8_t (*SCL_RandomFunction)(void); + +#if SCL_COUNT_EVALUATED_POSITIONS + uint32_t SCL_positionsEvaluated = 0; /**< If enabled by + SCL_COUNT_EVALUATED_POSITIONS, this + will increment with every + dynamically evaluated position (e.g. + when AI computes its move). */ +#endif + +#ifndef SCL_CALL_WDT_RESET + #define SCL_CALL_WDT_RESET 0 /**< Option that should be enabled on some + Arduinos. If 1, call to watchdog timer + reset will be performed during dynamic + evaluation (without it if AI takes long the + program will reset). */ +#endif + +/** + Returns a pseudorandom byte. This function has a period 256 and returns each + possible byte value exactly once in the period. +*/ +uint8_t SCL_randomSimple(void); +void SCL_randomSimpleSeed(uint8_t seed); + +/** + Like SCL_randomSimple, but internally uses a 16 bit value, so the period is + 65536. +*/ +uint8_t SCL_randomBetter(void); +void SCL_randomBetterSeed(uint16_t seed); + +#ifndef SCL_EVALUATION_FUNCTION + /** + If defined, AI will always use the static evaluation function with this + name. This helps avoid pointers to functions and can be faster but the + function can't be changed at runtime. + */ + #define SCL_EVALUATION_FUNCTION + #undef SCL_EVALUATION_FUNCTION +#endif + +#ifndef SCL_960_CASTLING + /** + If set, chess 960 (Fisher random) castling will be considered by the library + rather than normal castling. 960 castling is slightly different (e.g. + requires the inital rook positions to be stored in board state). The + castling move is performed as "capturing own rook". + */ + #define SCL_960_CASTLING 0 +#endif + +#ifndef SCL_ALPHA_BETA + /** + Turns alpha-beta pruning (AI optimization) on or off. This can gain + performance and should normally be turned on. AI behavior should not + change at all. + */ + #define SCL_ALPHA_BETA 1 +#endif + +/** + A set of game squares as a bit array, each bit representing one game square. + Useful for representing e.g. possible moves. To easily iterate over the set + use provided macros (SCL_SQUARE_SET_ITERATE, ...). +*/ +typedef uint8_t SCL_SquareSet[8]; + +#define SCL_SQUARE_SET_EMPTY {0, 0, 0, 0, 0, 0, 0, 0} + +void SCL_squareSetClear(SCL_SquareSet squareSet); +void SCL_squareSetAdd(SCL_SquareSet squareSet, uint8_t square); +uint8_t SCL_squareSetContains(const SCL_SquareSet squareSet, uint8_t square); +uint8_t SCL_squareSetSize(const SCL_SquareSet squareSet); +uint8_t SCL_squareSetEmpty(const SCL_SquareSet squareSet); + +/** + Returns a random square from a square set. +*/ +uint8_t SCL_squareSetGetRandom(const SCL_SquareSet squareSet, + SCL_RandomFunction randFunc); + +#define SCL_SQUARE_SET_ITERATE_BEGIN(squareSet) \ + { uint8_t iteratedSquare = 0;\ + uint8_t iterationEnd = 0;\ + for (int8_t _i = 0; _i < 8 && !iterationEnd; ++_i) {\ + uint8_t _row = squareSet[_i];\ + if (_row == 0) { iteratedSquare += 8; continue; }\ + \ + for (uint8_t _j = 0; _j < 8 && !iterationEnd; ++_j) {\ + if (_row & 0x01) { +/* + Between SCL_SQUARE_SET_ITERATE_BEGIN and _END iteratedSquare variable + represents the next square contained in the set. To break out of the + iteration set iterationEnd to 1. +*/ + +#define SCL_SQUARE_SET_ITERATE_END }\ + _row >>= 1;\ + iteratedSquare++;}\ + } /*for*/ } + +#define SCL_SQUARE_SET_ITERATE(squareSet,command)\ + SCL_SQUARE_SET_ITERATE_BEGIN(squareSet)\ + { command }\ + SCL_SQUARE_SET_ITERATE_END + +#define SCL_BOARD_STATE_SIZE 69 + +/** + Represents chess board state as a string in this format: + - First 64 characters represent the chess board (A1, B1, ... H8), each field + can be either a piece (PRNBKQprnbkq) or empty ('.'). I.e. the state looks + like this: + + 0 (A1) RNBQKBNR + PPPPPPPP + ........ + ........ + ........ + ........ + pppppppp + rnbqkbnr 63 (H8) + + - After this more bytes follow to represent global state, these are: + - 64: bits holding en-passant and castling related information: + - bits 0-3 (lsb): Column of the pawn that can, in current turn, be + taken by en-passant (0xF means no pawn can be taken this way). + - bit 4: Whether white is not prevented from short castling by previous + king or rook movement. + - bit 5: Same as 4, but for long castling. + - bit 6: Same as 4, but for black. + - bit 7: Same as 4, but for black and long castling. + - 65: Number saying the number of ply (half-moves) that have already been + played, also determining whose turn it currently is. + - 66: Move counter used in the 50 move rule, says the number of ply since + the last pawn move or capture. + - 67: Extra byte, left for storing additional info in variants. For normal + chess this byte should always be 0. + - 68: The last byte is always 0 to properly terminate the string in case + someone tries to print it. + - The state is designed so as to be simple and also print-friendly, i.e. you + can simply print it with line break after 8 characters to get a human + readable representation of the board. + + NOTE: there is a much more compact representation which however trades some + access speed which would affect the AI performance and isn't print friendly, + so we don't use it. In it each square takes 4 bits, using 15 out of 16 + possible values (empty square and W and B pieces including 2 types of pawns, + one "en-passant takeable"). Then only one extra byte needed is for castling + info (4 bits) and ply count (4 bits). +*/ +typedef char SCL_Board[SCL_BOARD_STATE_SIZE]; + +#define SCL_BOARD_ENPASSANT_CASTLE_BYTE 64 +#define SCL_BOARD_PLY_BYTE 65 +#define SCL_BOARD_MOVE_COUNT_BYTE 66 +#define SCL_BOARD_EXTRA_BYTE 67 + +#if SCL_960_CASTLING + #define _SCL_EXTRA_BYTE_VALUE (0 | (7 << 3)) // rooks on classic positions +#else + #define _SCL_EXTRA_BYTE_VALUE 0 +#endif + +#define SCL_BOARD_START_STATE \ + {82, 78, 66, 81, 75, 66, 78, 82,\ + 80, 80, 80, 80, 80, 80, 80, 80,\ + 46, 46, 46, 46, 46, 46, 46, 46,\ + 46, 46, 46, 46, 46, 46, 46, 46,\ + 46, 46, 46, 46, 46, 46, 46, 46,\ + 46, 46, 46, 46, 46, 46, 46, 46,\ + 112,112,112,112,112,112,112,112,\ + 114,110,98, 113,107,98, 110,114,\ + (char) 0xff,0,0,_SCL_EXTRA_BYTE_VALUE,0} + +#define SCL_FEN_START \ + "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1" + +#define SCL_FEN_HORDE \ + "ppp2ppp/pppppppp/pppppppp/pppppppp/3pp3/8/PPPPPPPP/RNBQKBNR w KQ - 0 1" + +#define SCL_FEN_UPSIDE_DOWN \ + "RNBKQBNR/PPPPPPPP/8/8/8/8/pppppppp/rnbkqbnr w - - 0 1" + +#define SCL_FEN_PEASANT_REVOLT \ + "1nn1k1n1/4p3/8/8/8/8/PPPPPPPP/4K3 w - - 0 1" + +#define SCL_FEN_ENDGAME \ + "4k3/pppppppp/8/8/8/8/PPPPPPPP/4K3 w - - 0 1" + +#define SCL_FEN_KNIGHTS \ + "N6n/1N4n1/2N2n2/3Nn3/k2nN2K/2n2N2/1n4N1/n6N w - - 0 1" + +/** + Holds an info required to undo a single move. +*/ +typedef struct +{ + uint8_t squareFrom; ///< start square + uint8_t squareTo; ///< target square + char enPassantCastle; ///< previous en passant/castle byte + char moveCount; ///< previous values of the move counter byte + uint8_t other; /**< lowest 7 bits: previous value of target square, + highest bit: if 1 then the move was promotion or + en passant */ +} SCL_MoveUndo; + +#define SCL_GAME_STATE_PLAYING 0x00 +#define SCL_GAME_STATE_WHITE_WIN 0x01 +#define SCL_GAME_STATE_BLACK_WIN 0x02 +#define SCL_GAME_STATE_DRAW 0x10 ///< further unspecified draw +#define SCL_GAME_STATE_DRAW_STALEMATE 0x11 ///< draw by stalemate +#define SCL_GAME_STATE_DRAW_REPETITION 0x12 ///< draw by repetition +#define SCL_GAME_STATE_DRAW_50 0x13 ///< draw by 50 move rule +#define SCL_GAME_STATE_DRAW_DEAD 0x14 ///< draw by dead position +#define SCL_GAME_STATE_END 0xff ///< end without known result + +/** + Converts square in common notation (e.g. 'c' 8) to square number. Only accepts + lowercase column. +*/ +#define SCL_SQUARE(colChar,rowInt) (((rowInt) - 1) * 8 + ((colChar) - 'a')) +#define SCL_S(c,r) SCL_SQUARE(c,r) + +void SCL_boardInit(SCL_Board board); +void SCL_boardCopy(const SCL_Board boardFrom, SCL_Board boardTo); + +/** + Initializes given chess 960 (Fisher random) position. If SCL_960_CASTLING + is not set, castling will be disabled by this function. +*/ +void SCL_boardInit960(SCL_Board board, uint16_t positionNumber); + +void SCL_boardDisableCastling(SCL_Board board); + +uint32_t SCL_boardHash32(const SCL_Board board); + +#define SCL_PHASE_OPENING 0 +#define SCL_PHASE_MIDGAME 1 +#define SCL_PHASE_ENDGAME 2 + +/** + Estimates the game phase: opening, midgame or endgame. +*/ +uint8_t SCL_boardEstimatePhase(SCL_Board board); + +/** + Sets the board position. The input string should be 64 characters long zero + terminated C string representing the board as squares A1, A2, ..., H8 with + each char being either a piece (RKBKQPrkbkqp) or an empty square ('.'). +*/ +void SCL_boardSetPosition(SCL_Board board, const char *pieces, + uint8_t castlingEnPassant, uint8_t moveCount, uint8_t ply); + +uint8_t SCL_boardsDiffer(SCL_Board b1, SCL_Board b2); + +/** + Function that prints out a single character. This is passed to printing + functions. +*/ +typedef void (*SCL_PutCharFunction)(char); + +/** + Gets a random move on given board for the player whose move it is. +*/ +void SCL_boardRandomMove(SCL_Board board, SCL_RandomFunction randFunc, + uint8_t *squareFrom, uint8_t *squareTo, char *resultProm); + +#define SCL_FEN_MAX_LENGTH 90 + +/** + Converts a position to FEN (Forsyth–Edwards Notation) string. The string has + to have at least SCL_FEN_MAX_LENGTH bytes allocated to guarantee the + function won't write to unallocated memory. The string will be terminated by + 0 (this is included in SCL_FEN_MAX_LENGTH). The number of bytes written + (including the terminating 0) is returned. +*/ +uint8_t SCL_boardToFEN(SCL_Board board, char *string); + +/** + Loads a board from FEN (Forsyth–Edwards Notation) string. Returns 1 on + success, 0 otherwise. XFEN isn't supported fully but a start position in + chess960 can be loaded with this function. +*/ +uint8_t SCL_boardFromFEN(SCL_Board board, const char *string); + +/** + Returns an approximate/heuristic board rating as a number, 0 meaning equal + chances for both players, positive favoring white, negative favoring black. +*/ +typedef int16_t (*SCL_StaticEvaluationFunction)(SCL_Board); + +/* + NOTE: int8_t as a return value was tried for evaluation function, which would + be simpler, but it fails to capture important non-material position + differences counted in fractions of pawn values, hence we have to use int16_t. +*/ + +/** + Basic static evaluation function. WARNING: this function supposes a standard + chess game, for non-standard positions it may either not work well or even + crash the program. You should use a different function for non-standard games. +*/ +int16_t SCL_boardEvaluateStatic(SCL_Board board); + +/** + Dynamic evaluation function (search), i.e. unlike SCL_boardEvaluateStatic, + this one performs a recursive search for deeper positions to get a more + accurate score. Of course, this is much slower and hugely dependent on + baseDepth (you mostly want to keep this under 5). +*/ +int16_t SCL_boardEvaluateDynamic(SCL_Board board, uint8_t baseDepth, + uint8_t extensionExtraDepth, SCL_StaticEvaluationFunction evalFunction); + +#define SCL_EVALUATION_MAX_SCORE 32600 // don't increase this, we need a margin + +/** + Checks if the board position is dead, i.e. mate is impossible (e.g. due to + insufficient material), which by the rules results in a draw. WARNING: This + function may fail to detect some dead positions as this is a non-trivial task. +*/ +uint8_t SCL_boardDead(SCL_Board board); + +/** + Tests whether given player is in check. +*/ +uint8_t SCL_boardCheck(SCL_Board board, uint8_t white); + +/** + Checks whether given move resets the move counter (used in the 50 move rule). +*/ +uint8_t SCL_boardMoveResetsCount(SCL_Board board, + uint8_t squareFrom, uint8_t squareTo); + +uint8_t SCL_boardMate(SCL_Board board); + +/** + Performs a move on a board WITHOUT checking if the move is legal. Returns an + info with which the move can be undone. +*/ +SCL_MoveUndo SCL_boardMakeMove(SCL_Board board, uint8_t squareFrom, uint8_t squareTo, + char promotePiece); + +void SCL_boardUndoMove(SCL_Board board, SCL_MoveUndo moveUndo); + +/** + Checks if the game is over, i.e. the current player to move has no legal + moves, the game is in dead position etc. +*/ +uint8_t SCL_boardGameOver(SCL_Board board); + +/** + Checks if given move is legal. +*/ +uint8_t SCL_boardMoveIsLegal(SCL_Board board, uint8_t squareFrom, + uint8_t squareTo); + +/** + Checks if the player to move has at least one legal move. +*/ +uint8_t SCL_boardMovePossible(SCL_Board board); + +#define SCL_POSITION_NORMAL 0x00 +#define SCL_POSITION_CHECK 0x01 +#define SCL_POSITION_MATE 0x02 +#define SCL_POSITION_STALEMATE 0x03 +#define SCL_POSITION_DEAD 0x04 + +uint8_t SCL_boardGetPosition(SCL_Board board); + +/** + Returns 1 if the square is attacked by player of given color. This is used to + examine checks, so for performance reasons the functions only checks whether + or not the square is attacked (not the number of attackers). +*/ +uint8_t SCL_boardSquareAttacked(SCL_Board board, uint8_t square, + uint8_t byWhite); + +/** + Gets pseudo moves of a piece: all possible moves WITHOUT eliminating moves + that lead to own check. To get only legal moves use SCL_boardGetMoves. +*/ +void SCL_boardGetPseudoMoves( + SCL_Board board, + uint8_t pieceSquare, + uint8_t checkCastling, + SCL_SquareSet result); + +/** + Gets all legal moves of given piece. +*/ +void SCL_boardGetMoves( + SCL_Board board, + uint8_t pieceSquare, + SCL_SquareSet result); + +void _SCL_board960RememberRookPositions(SCL_Board board); +void _SCL_boardPlaceOnNthAvailable(SCL_Board board, uint8_t pos, char piece); +void _SCL_handleRookActivity(SCL_Board board, uint8_t rookSquare); +void SCL_printSquareSet(SCL_SquareSet set, SCL_PutCharFunction putCharFunc); +int16_t _SCL_rateKingEndgamePosition(uint8_t position); +int16_t _SCL_boardEvaluateDynamic(SCL_Board board, int8_t depth, int16_t alphaBeta, int8_t takenSquare); + +static inline uint8_t SCL_boardWhitesTurn(SCL_Board board); + +static inline uint8_t SCL_pieceIsWhite(char piece); +static inline uint8_t SCL_squareIsWhite(uint8_t square); +char SCL_pieceToColor(uint8_t piece, uint8_t toWhite); + +/** + Converts square coordinates to square number. Each coordinate must be a number + <1,8>. Validity of the coordinates is NOT checked. +*/ +static inline uint8_t SCL_coordsToSquare(uint8_t row, uint8_t column); + +#ifndef SCL_VALUE_PAWN + #define SCL_VALUE_PAWN 256 +#endif + +#ifndef SCL_VALUE_KNIGHT + #define SCL_VALUE_KNIGHT 768 +#endif + +#ifndef SCL_VALUE_BISHOP + #define SCL_VALUE_BISHOP 800 +#endif + +#ifndef SCL_VALUE_ROOK + #define SCL_VALUE_ROOK 1280 +#endif + +#ifndef SCL_VALUE_QUEEN + #define SCL_VALUE_QUEEN 2304 +#endif + +#ifndef SCL_VALUE_KING + #define SCL_VALUE_KING 0 +#endif + +#define SCL_ENDGAME_MATERIAL_LIMIT \ + (2 * (SCL_VALUE_PAWN * 4 + SCL_VALUE_QUEEN + \ + SCL_VALUE_KING + SCL_VALUE_ROOK + SCL_VALUE_KNIGHT)) + +#define SCL_START_MATERIAL \ + (16 * SCL_VALUE_PAWN + 4 * SCL_VALUE_ROOK + 4 * SCL_VALUE_KNIGHT + \ + 4 * SCL_VALUE_BISHOP + 2 * SCL_VALUE_QUEEN + 2 * SCL_VALUE_KING) + +#ifndef SCL_RECORD_MAX_LENGTH + #define SCL_RECORD_MAX_LENGTH 256 +#endif + +#define SCL_RECORD_MAX_SIZE (SCL_RECORD_MAX_LENGTH * 2) + +/** + Records a single chess game. The format is following: + + Each record item consists of 2 bytes which record a single move (ply): + + abxxxxxx cdyyyyyy + + xxxxxx Start square of the move, counted as A0, A1, ... + yyyyyy End square of the move in the same format as the start square. + ab 00 means this move isn't the last move of the game, other possible + values are 01: white wins, 10: black wins, 11: draw or end for + other reasons. + cd In case of pawn promotion move this encodes the promoted piece as + 00: queen, 01: rook, 10: bishop, 11: knight (pawn isn't allowed by + chess rules). + + Every record should be ended by an ending move (ab != 00), empty record should + have one move where xxxxxx == yyyyyy == 0 and ab == 11. +*/ +typedef uint8_t SCL_Record[SCL_RECORD_MAX_SIZE]; + +#define SCL_RECORD_CONT 0x00 +#define SCL_RECORD_W_WIN 0x40 +#define SCL_RECORD_B_WIN 0x80 +#define SCL_RECORD_END 0xc0 + +#define SCL_RECORD_PROM_Q 0x00 +#define SCL_RECORD_PROM_R 0x40 +#define SCL_RECORD_PROM_B 0x80 +#define SCL_RECORD_PROM_N 0xc0 + +#define SCL_RECORD_ITEM(s0,s1,p,e) ((e) | (s0)),((p) | (s1)) + +void SCL_recordInit(SCL_Record r); + +void SCL_recordCopy(SCL_Record recordFrom, SCL_Record recordTo); + +/** + Represents a complete game of chess (or a variant with different staring + position). This struct along with associated functions allows to easily + implement a chess game that allows undoing moves, detecting draws, recording + the moves etc. On platforms with extremely little RAM one can reduce + SCL_RECORD_MAX_LENGTH to reduce the size of this struct (which will however + possibly limit how many moves can be undone). +*/ +typedef struct +{ + SCL_Board board; + SCL_Record record; /**< Holds the game record. This record is here + firstly because games are usually recorded and + secondly this allows undoing moves up to the + beginning of the game. This infinite undoing will + only work as long as the record is able to hold + the whole game; if the record is full, undoing is + no longet possible. */ + uint16_t state; + uint16_t ply; ///< ply count (board ply counter is only 8 bit) + + uint32_t prevMoves[14]; ///< stores last moves, for repetition detection + + const char *startState; /**< Optional pointer to the starting board state. + If this is null, standard chess start position is + assumed. This is needed for undoing moves with + game record. */ +} SCL_Game; + +/** + Initializes a new chess game. The startState parameter is optional and allows + for setting up chess variants that differ by starting positions, setting this + to 0 will assume traditional starting position. WARNING: if startState is + provided, the pointed to board mustn't be deallocated afterwards, the string + is not internally copied (for memory saving reasons). +*/ +void SCL_gameInit(SCL_Game *game, const SCL_Board startState); + +void SCL_gameMakeMove(SCL_Game *game, uint8_t squareFrom, uint8_t squareTo, + char promoteTo); + +uint8_t SCL_gameUndoMove(SCL_Game *game); + +/** + Gets a move which if played now would cause a draw by repetition. Returns 1 + if such move exists, 0 otherwise. The results parameters can be set to 0 in + which case they will be ignored and only the existence of a draw move will be + tested. +*/ +uint8_t SCL_gameGetRepetiotionMove(SCL_Game *game, + uint8_t *squareFrom, uint8_t *squareTo); + +/** + Leads a game record from PGN string. The function will probably not strictly + adhere to the PGN input format, but should accept most sanely written PGN + strings. +*/ +void SCL_recordFromPGN(SCL_Record r, const char *pgn); + +uint16_t SCL_recordLength(const SCL_Record r); + +/** + Gets the move out of a game record, returns the end state of the move + (SCL_RECORD_CONT, SCL_RECORD_END etc.) +*/ +uint8_t SCL_recordGetMove(const SCL_Record r, uint16_t index, + uint8_t *squareFrom, uint8_t *squareTo, char *promotedPiece); + +/** + Adds another move to the game record. Terminating the record is handled so + that the last move is always marked with end flag, endState is here to only + indicate possible game result (otherwise pass SCL_RECORD_CONT). Returns 1 if + the item was added, otherwise 0 (replay was already of maximum size). +*/ +uint8_t SCL_recordAdd(SCL_Record r, uint8_t squareFrom, + uint8_t squareTo, char promotePiece, uint8_t endState); + +/** + Removes the last move from the record, returns 1 if the replay is non-empty + after the removal, otherwise 0. +*/ +uint8_t SCL_recordRemoveLast(SCL_Record r); + +/** + Applies given number of half-moves (ply) to a given board (the board is + automatically initialized at the beginning). +*/ +void SCL_recordApply(const SCL_Record r, SCL_Board b, uint16_t moves); + +int16_t SCL_pieceValue(char piece); +int16_t SCL_pieceValuePositive(char piece); + +#define SCL_PRINT_FORMAT_NONE 0 +#define SCL_PRINT_FORMAT_NORMAL 1 +#define SCL_PRINT_FORMAT_COMPACT 2 +#define SCL_PRINT_FORMAT_UTF8 3 +#define SCL_PRINT_FORMAT_COMPACT_UTF8 4 + +/** + Gets the best move for the currently moving player as computed by AI. The + return value is the value of the move (with the same semantics as the value + of an evaluation function). baseDepth is depth in plys to which all moves will + be checked. If baseDepth 0 is passed, the function makes a random move and + returns the evaluation of the board. extensionExtraDepth is extra depth for + checking specific situations like exchanges and checks. endgameExtraDepth is + extra depth which is added to baseDepth in the endgame. If the randomness + function is 0, AI will always make the first best move it finds, if it is + not 0 and randomness is 0, AI will randomly pick between the equally best + moves, if it is not 0 and randomness is positive, AI will randomly choose + between best moves with some bias (may not pick the best rated move). +*/ +int16_t SCL_getAIMove( + SCL_Board board, + uint8_t baseDepth, + uint8_t extensionExtraDepth, + uint8_t endgameExtraDepth, + SCL_StaticEvaluationFunction evalFunc, + SCL_RandomFunction randFunc, + uint8_t randomness, + uint8_t repetitionMoveFrom, + uint8_t repetitionMoveTo, + uint8_t *resultFrom, + uint8_t *resultTo, + char *resultProm); + +/** + Prints given chessboard using given format and an abstract printing function. +*/ +void SCL_printBoard( + SCL_Board board, + SCL_PutCharFunction putCharFunc, + SCL_SquareSet highlightSquares, + uint8_t selectSquare, + uint8_t format, + uint8_t offset, + uint8_t labels, + uint8_t blackDown); + +void SCL_printBoardSimple( + SCL_Board board, + SCL_PutCharFunction putCharFunc, + uint8_t selectSquare, + uint8_t format); + +void SCL_printSquareUTF8(uint8_t square, SCL_PutCharFunction putCharFunc); +void SCL_printPGN(SCL_Record r, SCL_PutCharFunction putCharFunc, + SCL_Board initialState); + +/** + Reads a move from string (the notation format is described at the top of this + file). The function is safe as long as the string is 0 terminated. Returns 1 + on success or 0 on fail (invalid move string). +*/ +uint8_t SCL_stringToMove(const char *moveString, uint8_t *resultFrom, + uint8_t *resultTo, char *resultPromotion); + +char *SCL_moveToString(SCL_Board board, uint8_t s0, uint8_t s1, + char promotion, char *string); + +/** + Function used in drawing, it is called to draw the next pixel. The first + parameter is the pixel color, the second one if the sequential number of the + pixel. +*/ +typedef void (*SCL_PutPixelFunction)(uint8_t, uint16_t); + +#define SCL_BOARD_PICTURE_WIDTH 64 + +/** + Draws a simple 1bit 64x64 pixels board using a provided abstract function for + drawing pixels. The function renders from top left to bottom right, i.e. no + frame buffer is required. +*/ +void SCL_drawBoard( + SCL_Board board, + SCL_PutPixelFunction putPixel, + uint8_t selectedSquare, + SCL_SquareSet highlightSquares, + uint8_t blackDown); + +/** + Converts square number to string representation (e.g. "d2"). This function + will modify exactly the first two bytes of the provided string. +*/ +static inline char *SCL_squareToString(uint8_t square, char *string); + +/** + Converts a string, such as "A1" or "b4", to square number. The string must + start with a letter (lower or upper case) and be followed by a number <1,8>. + Validity of the string is NOT checked. +*/ +uint8_t SCL_stringToSquare(const char *square); + +//============================================================================= +// privates: + +#define SCL_UNUSED(v) (void)(v) + +uint8_t SCL_currentRandom8 = 0; + +uint16_t SCL_currentRandom16 = 0; + +void SCL_randomSimpleSeed(uint8_t seed) +{ + SCL_currentRandom8 = seed; +} + +uint8_t SCL_randomSimple(void) +{ + SCL_currentRandom8 *= 13; + SCL_currentRandom8 += 7; + return SCL_currentRandom8; +} + +uint8_t SCL_randomBetter(void) +{ + SCL_currentRandom16 *= 13; + SCL_currentRandom16 += 7; + return (SCL_currentRandom16 % 256) ^ (SCL_currentRandom16 / 256); +} + +void SCL_randomBetterSeed(uint16_t seed) +{ + SCL_currentRandom16 = seed; +} + +void SCL_squareSetClear(SCL_SquareSet squareSet) +{ + for (uint8_t i = 0; i < 8; ++i) + squareSet[i] = 0; +} + +uint8_t SCL_stringToSquare(const char *square) +{ + return (square[1] - '1') * 8 + + (square[0] - ((square[0] >= 'A' && square[0] <= 'Z') ? 'A' : 'a')); +} + +char *SCL_moveToString(SCL_Board board, uint8_t s0, uint8_t s1, + char promotion, char *string) +{ + char *result = string; + + SCL_squareToString(s0,string); + string += 2; + string = SCL_squareToString(s1,string); + string += 2; + + char c = board[s0]; + + if (c == 'p' || c == 'P') + { + uint8_t rank = s1 / 8; + + if (rank == 0 || rank == 7) + { + *string = promotion; + string++; + } + } + + *string = 0; + + return result; +} + +uint8_t SCL_boardWhitesTurn(SCL_Board board) +{ + return (board[SCL_BOARD_PLY_BYTE] % 2) == 0; +} + +uint8_t SCL_coordsToSquare(uint8_t row, uint8_t column) +{ + return row * 8 + column; +} + +uint8_t SCL_pieceIsWhite(char piece) +{ + return piece < 'a'; +} + +char *SCL_squareToString(uint8_t square, char *string) +{ + string[0] = 'a' + square % 8; + string[1] = '1' + square / 8; + + return string; +} + +uint8_t SCL_squareIsWhite(uint8_t square) +{ + return (square % 2) != ((square / 8) % 2); +} + +char SCL_pieceToColor(uint8_t piece, uint8_t toWhite) +{ + return (SCL_pieceIsWhite(piece) == toWhite) ? + piece : (piece + (toWhite ? -32 : 32)); +} + +/** + Records the rook starting positions in the board state. This is required in + chess 960 in order to be able to correctly perform castling (castling rights + knowledge isn't enough as one rook might have moved to the other side and we + wouldn't know which one can castle and which not). +*/ +void _SCL_board960RememberRookPositions(SCL_Board board) +{ + uint8_t pos = 0; + uint8_t rooks = 2; + + while (pos < 8 && rooks != 0) + { + if (board[pos] == 'R') + { + board[SCL_BOARD_EXTRA_BYTE] = rooks == 2 ? pos : + (board[SCL_BOARD_EXTRA_BYTE] | (pos << 3)); + + rooks--; + } + + pos++; + } +} + +void SCL_boardInit(SCL_Board board) +{ + /* + We might use SCL_BOARD_START_STATE and copy it to the board, but that might + waste RAM on Arduino, so we init the board by code. + */ + + char *b = board; + + *b = 'R'; b++; *b = 'N'; b++; + *b = 'B'; b++; *b = 'Q'; b++; + *b = 'K'; b++; *b = 'B'; b++; + *b = 'N'; b++; *b = 'R'; b++; + + char *b2 = board + 48; + + for (uint8_t i = 0; i < 8; ++i, b++, b2++) + { + *b = 'P'; + *b2 = 'p'; + } + + for (uint8_t i = 0; i < 32; ++i, b++) + *b = '.'; + + b += 8; + + *b = 'r'; b++; *b = 'n'; b++; + *b = 'b'; b++; *b = 'q'; b++; + *b = 'k'; b++; *b = 'b'; b++; + *b = 'n'; b++; *b = 'r'; b++; + + for (uint8_t i = 0; i < SCL_BOARD_STATE_SIZE - SCL_BOARD_SQUARES; ++i, ++b) + *b = 0; + + board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] = (char) 0xff; + +#if SCL_960_CASTLING + _SCL_board960RememberRookPositions(board); +#endif +} + +void _SCL_boardPlaceOnNthAvailable(SCL_Board board, uint8_t pos, char piece) +{ + char *c = board; + + while (1) + { + if (*c == '.') + { + if (pos == 0) + break; + + pos--; + } + + c++; + } + + *c = piece; +} + +void SCL_boardInit960(SCL_Board board, uint16_t positionNumber) +{ + SCL_Board b; + + SCL_boardInit(b); + + for (uint8_t i = 0; i < SCL_BOARD_STATE_SIZE; ++i) + board[i] = ((i >= 8 && i < 56) || i >= 64) ? b[i] : '.'; + + uint8_t helper = positionNumber % 16; + + board[(helper / 4) * 2] = 'B'; + board[1 + (helper % 4) * 2] = 'B'; + + helper = positionNumber / 16; + + // maybe there's a simpler way :) + + _SCL_boardPlaceOnNthAvailable(board,helper % 6,'Q'); + _SCL_boardPlaceOnNthAvailable(board,0,helper <= 23 ? 'N' : 'R'); + + _SCL_boardPlaceOnNthAvailable(board,0, + (helper >= 7 && helper <= 23) ? 'R' : + (helper > 41 ? 'K' : 'N' )); + + _SCL_boardPlaceOnNthAvailable(board,0, + (helper <= 5 || helper >= 54) ? 'R' : + (((helper >= 12 && helper <= 23) || + (helper >= 30 && helper <= 41)) ? 'K' : 'N')); + + _SCL_boardPlaceOnNthAvailable(board,0, + (helper <= 11 || (helper <= 29 && helper >= 24)) ? 'K' : + ( + ( + (helper >= 18 && helper <= 23) || + (helper >= 36 && helper <= 41) || + (helper >= 48 && helper <= 53) + ) ? 'R' : 'N' + ) + ); + + uint8_t rooks = 0; + + for (uint8_t i = 0; i < 8; ++i) + if (board[i] == 'R') + rooks++; + + _SCL_boardPlaceOnNthAvailable(board,0,rooks == 2 ? 'N' : 'R'); + + for (uint8_t i = 0; i < 8; ++i) + board[56 + i] = SCL_pieceToColor(board[i],0); + +#if SCL_960_CASTLING + _SCL_board960RememberRookPositions(board); +#else + SCL_boardDisableCastling(board); +#endif +} + +uint8_t SCL_boardsDiffer(SCL_Board b1, SCL_Board b2) +{ + const char *p1 = b1, *p2 = b2; + + while (p1 < b1 + SCL_BOARD_STATE_SIZE) + { + if (*p1 != *p2) + return 1; + + p1++; + p2++; + } + + return 0; +} + +void SCL_recordInit(SCL_Record r) +{ + r[0] = 0 | SCL_RECORD_END; + r[1] = 0; +} + +void SCL_recordFromPGN(SCL_Record r, const char *pgn) +{ + SCL_Board board; + + SCL_boardInit(board); + + SCL_recordInit(r); + + uint8_t state = 0; + uint8_t evenMove = 0; + + while (*pgn != 0) + { + switch (state) + { + case 0: // skipping tags and spaces, outside [] + if (*pgn == '1') + state = 2; + else if (*pgn == '[') + state = 1; + + break; + + case 1: // skipping tags and spaces, inside [] + if (*pgn == ']') + state = 0; + + break; + + case 2: // reading move number + if (*pgn == '{') + state = 3; + else if ((*pgn >= 'a' && *pgn <= 'h') || (*pgn >= 'A' && *pgn <= 'Z')) + { + state = 4; + pgn--; + } + + break; + + case 3: // initial comment + if (*pgn == '}') + state = 2; + + break; + + case 4: // reading move + { + char piece = 'p'; + char promoteTo = 'q'; + uint8_t castle = 0; + uint8_t promotion = 0; + + int8_t coords[4]; + + uint8_t ranks = 0, files = 0; + + for (uint8_t i = 0; i < 4; ++i) + coords[i] = -1; + + while (*pgn != ' ' && *pgn != '\n' && + *pgn != '\t' && *pgn != '{' && *pgn != 0) + { + if (*pgn == '=') + promotion = 1; + if (*pgn == 'O' || *pgn == '0') + castle++; + if (*pgn >= 'A' && *pgn <= 'Z') + { + if (promotion) + promoteTo = *pgn; + else + piece = *pgn; + } + else if (*pgn >= 'a' && *pgn <= 'h') + { + coords[files * 2] = *pgn - 'a'; + files++; + } + else if (*pgn >= '1' && *pgn <= '8') + { + coords[1 + ranks * 2] = *pgn - '1'; + ranks++; + } + + pgn++; + } + + if (castle) + { + piece = 'K'; + + coords[0] = 4; + coords[1] = 0; + coords[2] = castle < 3 ? 6 : 2; + coords[3] = 0; + + if (evenMove) + { + coords[1] = 7; + coords[3] = 7; + } + } + + piece = SCL_pieceToColor(piece,evenMove == 0); + + if (coords[2] < 0) + { + coords[2] = coords[0]; + coords[0] = -1; + } + + if (coords[3] < 0) + { + coords[3] = coords[1]; + coords[1] = -1; + } + + uint8_t squareTo = coords[3] * 8 + coords[2]; + + if (coords[0] < 0 || coords[1] < 0) + { + // without complete starting coords we have to find the piece + + for (int i = 0; i < SCL_BOARD_SQUARES; ++i) + if (board[i] == piece) + { + SCL_SquareSet s; + + SCL_squareSetClear(s); + + SCL_boardGetMoves(board,i,s); + + if (SCL_squareSetContains(s,squareTo) && + (coords[0] < 0 || coords[0] == i % 8) && + (coords[1] < 0 || coords[1] == i / 8)) + { + coords[0] = i % 8; + coords[1] = i / 8; + break; + } + } + } + + uint8_t squareFrom = coords[1] * 8 + coords[0]; + + SCL_boardMakeMove(board,squareFrom,squareTo,promoteTo); + +// for some reason tcc bugs here, the above line sets squareFrom to 0 lol +// can be fixed with doing "squareFrom = coords[1] * 8 + coords[0];" again + + SCL_recordAdd(r,squareFrom,squareTo,promoteTo,SCL_RECORD_CONT); + + while (*pgn == ' ' || *pgn == '\n' || *pgn == '\t' || *pgn == '{') + { + if (*pgn == '{') + while (*pgn != '}') + pgn++; + + pgn++; + } + + if (*pgn == 0) + return; + + pgn--; + + if (evenMove) + state = 2; + + evenMove = !evenMove; + + break; + } + + default: break; + } + + pgn++; + } +} + +uint16_t SCL_recordLength(const SCL_Record r) +{ + if ((r[0] & 0x3f) == (r[1] & 0x3f)) // empty record that's only terminator + return 0; + + uint16_t result = 0; + + while ((r[result] & 0xc0) == 0) + result += 2; + + return (result / 2) + 1; +} + +uint8_t SCL_recordGetMove(const SCL_Record r, uint16_t index, + uint8_t *squareFrom, uint8_t *squareTo, char *promotedPiece) +{ + index *= 2; + + uint8_t b = r[index]; + + *squareFrom = b & 0x3f; + uint8_t result = b & 0xc0; + + index++; + + b = r[index]; + + *squareTo = b & 0x3f; + + b &= 0xc0; + + switch (b) + { + case SCL_RECORD_PROM_Q: *promotedPiece = 'q'; break; + case SCL_RECORD_PROM_R: *promotedPiece = 'r'; break; + case SCL_RECORD_PROM_B: *promotedPiece = 'b'; break; + case SCL_RECORD_PROM_N: + default: *promotedPiece = 'n'; break; + } + + return result; +} + +uint8_t SCL_recordAdd(SCL_Record r, uint8_t squareFrom, + uint8_t squareTo, char promotePiece, uint8_t endState) +{ + uint16_t l = SCL_recordLength(r); + + if (l >= SCL_RECORD_MAX_LENGTH) + return 0; + + l *= 2; + + if (l != 0) + r[l - 2] &= 0x3f; // remove the end flag from previous item + + if (endState == SCL_RECORD_CONT) + endState = SCL_RECORD_END; + + r[l] = squareFrom | endState; + + uint8_t p; + + switch (promotePiece) + { + case 'n': case 'N': p = SCL_RECORD_PROM_N; break; + case 'b': case 'B': p = SCL_RECORD_PROM_B; break; + case 'r': case 'R': p = SCL_RECORD_PROM_R; break; + case 'q': case 'Q': + default: p = SCL_RECORD_PROM_Q; break; + } + + l++; + + r[l] = squareTo | p; + + return 1; +} + +uint8_t SCL_recordRemoveLast(SCL_Record r) +{ + uint16_t l = SCL_recordLength(r); + + if (l == 0) + return 0; + + if (l == 1) + SCL_recordInit(r); + else + { + l = (l - 2) * 2; + + r[l] = (r[l] & 0x3f) | SCL_RECORD_END; + } + + return 1; +} + +void SCL_recordApply(const SCL_Record r, SCL_Board b, uint16_t moves) +{ + SCL_boardInit(b); + + uint16_t l = SCL_recordLength(r); + + if (moves > l) + moves = l; + + for (uint16_t i = 0; i < moves; ++i) + { + uint8_t s0, s1; + char p; + + SCL_recordGetMove(r,i,&s0,&s1,&p); + SCL_boardMakeMove(b,s0,s1,p); + } +} + +void SCL_boardUndoMove(SCL_Board board, SCL_MoveUndo moveUndo) +{ +#if SCL_960_CASTLING + char squareToNow = board[moveUndo.squareTo]; +#endif + + board[moveUndo.squareFrom] = board[moveUndo.squareTo]; + board[moveUndo.squareTo] = moveUndo.other & 0x7f; + board[SCL_BOARD_PLY_BYTE]--; + board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] = moveUndo.enPassantCastle; + board[SCL_BOARD_MOVE_COUNT_BYTE] = moveUndo.moveCount; + + if (moveUndo.other & 0x80) + { + moveUndo.squareTo /= 8; + + if (moveUndo.squareTo == 0 || moveUndo.squareTo == 7) + board[moveUndo.squareFrom] = SCL_pieceIsWhite(board[moveUndo.squareFrom]) + ? 'P' : 'p'; + // ^ was promotion + else + board[(moveUndo.squareFrom / 8) * 8 + (moveUndo.enPassantCastle & 0x0f)] = + (board[moveUndo.squareFrom] == 'P') ? 'p' : 'P'; // was en passant + } +#if !SCL_960_CASTLING + else if (board[moveUndo.squareFrom] == 'k' && // black castling + moveUndo.squareFrom == 60) + { + if (moveUndo.squareTo == 58) + { + board[59] = '.'; + board[56] = 'r'; + } + else if (moveUndo.squareTo == 62) + { + board[61] = '.'; + board[63] = 'r'; + } + } + else if (board[moveUndo.squareFrom] == 'K' && // white castling + moveUndo.squareFrom == 4) + { + if (moveUndo.squareTo == 2) + { + board[3] = '.'; + board[0] = 'R'; + } + else if (moveUndo.squareTo == 6) + { + board[5] = '.'; + board[7] = 'R'; + } + } +#else // 960 castling + else if (((moveUndo.other & 0x7f) == 'r') && // black castling + (squareToNow == '.' || !SCL_pieceIsWhite(squareToNow))) + { + board[moveUndo.squareTo < moveUndo.squareFrom ? 59 : 61] = '.'; + board[moveUndo.squareTo < moveUndo.squareFrom ? 58 : 62] = '.'; + + board[moveUndo.squareFrom] = 'k'; + board[moveUndo.squareTo] = 'r'; + } + else if (((moveUndo.other & 0x7f) == 'R') && // white castling + (squareToNow == '.' || SCL_pieceIsWhite(squareToNow))) + { + board[moveUndo.squareTo < moveUndo.squareFrom ? 3 : 5] = '.'; + board[moveUndo.squareTo < moveUndo.squareFrom ? 2 : 6] = '.'; + + board[moveUndo.squareFrom] = 'K'; + board[moveUndo.squareTo] = 'R'; + } +#endif +} + +/** + Potentially disables castling rights according to whether something moved from + or to a square with a rook. +*/ +void _SCL_handleRookActivity(SCL_Board board, uint8_t rookSquare) +{ +#if !SCL_960_CASTLING + switch (rookSquare) + { + case 0: board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] &= (uint8_t) ~0x20; break; + case 7: board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] &= (uint8_t) ~0x10; break; + case 56: board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] &= (uint8_t) ~0x80; break; + case 63: board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] &= (uint8_t) ~0x40; break; + default: break; + } +#else // 960 castling + if (rookSquare == (board[SCL_BOARD_EXTRA_BYTE] & 0x07)) + board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] &= (uint8_t) ~0x20; + else if (rookSquare == (board[SCL_BOARD_EXTRA_BYTE] >> 3)) + board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] &= (uint8_t) ~0x10; + else if (rookSquare == 56 + (board[SCL_BOARD_EXTRA_BYTE] & 0x07)) + board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] &= (uint8_t) ~0x80; + else if (rookSquare == 56 + (board[SCL_BOARD_EXTRA_BYTE] >> 3)) + board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] &= (uint8_t) ~0x40; +#endif +} + +SCL_MoveUndo SCL_boardMakeMove(SCL_Board board, uint8_t squareFrom, uint8_t squareTo, + char promotePiece) +{ + char s = board[squareFrom]; + + SCL_MoveUndo moveUndo; + + moveUndo.squareFrom = squareFrom; + moveUndo.squareTo = squareTo; + moveUndo.moveCount = board[SCL_BOARD_MOVE_COUNT_BYTE]; + moveUndo.enPassantCastle = board[SCL_BOARD_ENPASSANT_CASTLE_BYTE]; + moveUndo.other = board[squareTo]; + + // reset the en-passant state + board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] |= 0x0f; + + if (SCL_boardMoveResetsCount(board,squareFrom,squareTo)) + board[SCL_BOARD_MOVE_COUNT_BYTE] = 0; + else + board[SCL_BOARD_MOVE_COUNT_BYTE]++; + +#if SCL_960_CASTLING + uint8_t castled = 0; +#endif + + if ((s == 'k') || (s == 'K')) + { +#if !SCL_960_CASTLING + if ((squareFrom == 4) || (squareFrom == 60)) // check castling + { + int8_t difference = squareTo - squareFrom; + + char rook = SCL_pieceToColor('r',SCL_pieceIsWhite(s)); + + if (difference == 2) // short + { + board[squareTo - 1] = rook; + board[squareTo + 1] = '.'; + } + else if (difference == -2) // long + { + board[squareTo - 2] = '.'; + board[squareTo + 1] = rook; + } + } +#else // 960 castling + uint8_t isWhite = SCL_pieceIsWhite(s); + char rook = SCL_pieceToColor('r',isWhite); + + if (board[squareTo] == rook) + { + castled = 1; + + board[squareFrom] = '.'; + board[squareTo] = '.'; + + if (squareTo > squareFrom) // short + { + board[isWhite ? 6 : (56 + 6)] = s; + board[isWhite ? 5 : (56 + 5)] = rook; + } + else // long + { + board[isWhite ? 2 : (56 + 2)] = s; + board[isWhite ? 3 : (56 + 3)] = rook; + } + } +#endif + + // after king move disable castling + board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] &= ~(0x03 << ((s == 'K') ? 4 : 6)); + } + else if ((s == 'p') || (s == 'P')) + { + uint8_t row = squareTo / 8; + + int8_t rowDiff = squareFrom / 8 - row; + + if (rowDiff == 2 || rowDiff == -2) // record en passant column + { + board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] = + (board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] & 0xf0) | (squareFrom % 8); + } + + if (row == 0 || row == 7) + { + // promotion + s = SCL_pieceToColor(promotePiece,SCL_pieceIsWhite(s)); + + moveUndo.other |= 0x80; + } + else + { + // check en passant move + + int8_t columnDiff = (squareTo % 8) - (squareFrom % 8); + + if ((columnDiff != 0) && (board[squareTo] == '.')) + { + board[squareFrom + columnDiff] = '.'; + moveUndo.other |= 0x80; + } + } + } + else if ((s == 'r') || (s == 'R')) + _SCL_handleRookActivity(board,squareFrom); + + char taken = board[squareTo]; + + // taking a rook may also disable castling: + + if (taken == 'R' || taken == 'r') + _SCL_handleRookActivity(board,squareTo); + +#if SCL_960_CASTLING + if (!castled) +#endif + { + board[squareTo] = s; + board[squareFrom] = '.'; + } + + board[SCL_BOARD_PLY_BYTE]++; // increase ply count + + return moveUndo; +} + +void SCL_boardSetPosition(SCL_Board board, const char *pieces, + uint8_t castlingEnPassant, uint8_t moveCount, uint8_t ply) +{ + for (uint8_t i = 0; i < SCL_BOARD_SQUARES; ++i, pieces++) + if (*pieces != 0) + board[i] = *pieces; + else + break; + + board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] = castlingEnPassant; + board[SCL_BOARD_PLY_BYTE] = ply; + board[SCL_BOARD_MOVE_COUNT_BYTE] = moveCount; + board[SCL_BOARD_STATE_SIZE - 1] = 0; +} + +void SCL_squareSetAdd(SCL_SquareSet squareSet, uint8_t square) +{ + squareSet[square / 8] |= 0x01 << (square % 8); +} + +uint8_t SCL_squareSetContains(const SCL_SquareSet squareSet, uint8_t square) +{ + return squareSet[square / 8] & (0x01 << (square % 8)); +} + +uint8_t SCL_squareSetSize(const SCL_SquareSet squareSet) +{ + uint8_t result = 0; + + for (uint8_t i = 0; i < 8; ++i) + { + uint8_t byte = squareSet[i]; + + for (uint8_t j = 0; j < 8; ++j) + { + result += byte & 0x01; + byte >>= 1; + } + } + + return result; +} + +uint8_t SCL_squareSetEmpty(const SCL_SquareSet squareSet) +{ + for (uint8_t i = 0; i < 8; ++i) + if (squareSet[i] != 0) + return 0; + + return 1; +} + +uint8_t SCL_squareSetGetRandom( + const SCL_SquareSet squareSet, SCL_RandomFunction randFunc) +{ + uint8_t size = SCL_squareSetSize(squareSet); + + if (size == 0) + return 0; + + uint8_t n = (randFunc() % size) + 1; + uint8_t i = 0; + + while (i < SCL_BOARD_SQUARES) + { + if (SCL_squareSetContains(squareSet,i)) + { + n--; + + if (n == 0) + break; + } + + ++i; + } + + return i; +} + +void SCL_boardCopy(const SCL_Board boardFrom, SCL_Board boardTo) +{ + for (uint8_t i = 0; i < SCL_BOARD_STATE_SIZE; ++i) + boardTo[i] = boardFrom[i]; +} + +uint8_t SCL_boardSquareAttacked( + SCL_Board board, + uint8_t square, + uint8_t byWhite) +{ + const char *currentSquare = board; + + /* We need to place a temporary piece on the tested square in order to test if + the square is attacked (consider testing if attacked by a pawn). */ + + char previous = board[square]; + + board[square] = SCL_pieceToColor('r',!byWhite); + + for (uint8_t i = 0; i < SCL_BOARD_SQUARES; ++i, ++currentSquare) + { + char s = *currentSquare; + + if ((s == '.') || (SCL_pieceIsWhite(s) != byWhite)) + continue; + + SCL_SquareSet moves; + SCL_boardGetPseudoMoves(board,i,0,moves); + + if (SCL_squareSetContains(moves,square)) + { + board[square] = previous; + return 1; + } + } + + board[square] = previous; + return 0; +} + +uint8_t SCL_boardCheck(SCL_Board board,uint8_t white) +{ + const char *square = board; + char kingChar = white ? 'K' : 'k'; + + for (uint8_t i = 0; i < SCL_BOARD_SQUARES; ++i, ++square) + if ((*square == kingChar && + SCL_boardSquareAttacked(board,i,!white))) + return 1; + + return 0; +} + +uint8_t SCL_boardGameOver(SCL_Board board) +{ + uint8_t position = SCL_boardGetPosition(board); + + return (position == SCL_POSITION_MATE) || + (position == SCL_POSITION_STALEMATE) || + (position == SCL_POSITION_DEAD); +} + +uint8_t SCL_boardMovePossible(SCL_Board board) +{ + uint8_t white = SCL_boardWhitesTurn(board); + + for (uint8_t i = 0; i < SCL_BOARD_SQUARES; ++i) + { + char s = board[i]; + + if ((s != '.') && (SCL_pieceIsWhite(s) == white)) + { + SCL_SquareSet moves; + + SCL_boardGetMoves(board,i,moves); + + if (SCL_squareSetSize(moves) != 0) + return 1; + } + } + + return 0; +} + +uint8_t SCL_boardMate(SCL_Board board) +{ + return SCL_boardGetPosition(board) == SCL_POSITION_MATE; +} + +void SCL_boardGetPseudoMoves( + SCL_Board board, + uint8_t pieceSquare, + uint8_t checkCastling, + SCL_SquareSet result) +{ + char piece = board[pieceSquare]; + + SCL_squareSetClear(result); + + uint8_t isWhite = SCL_pieceIsWhite(piece); + int8_t horizontalPosition = pieceSquare % 8; + int8_t pawnOffset = -8; + + switch (piece) + { + case 'P': + pawnOffset = 8; + // intentional fallthrough + case 'p': + { + uint8_t square = pieceSquare + pawnOffset; + uint8_t verticalPosition = pieceSquare / 8; + + if (board[square] == '.') // forward move + { + SCL_squareSetAdd(result,square); + + if (verticalPosition == (1 + (piece == 'p') * 5)) // start position? + { + uint8_t square2 = square + pawnOffset; + + if (board[square2] == '.') + SCL_squareSetAdd(result,square2); + } + } + + #define checkDiagonal(hor,add) \ + if (horizontalPosition != hor) \ + { \ + uint8_t square2 = square + add; \ + char c = board[square2]; \ + if (c != '.' && SCL_pieceIsWhite(c) != isWhite) \ + SCL_squareSetAdd(result,square2); \ + } + + // diagonal moves + checkDiagonal(0,-1) + checkDiagonal(7,1) + + uint8_t enPassantRow = 4; + uint8_t enemyPawn = 'p'; + + if (piece == 'p') + { + enPassantRow = 3; + enemyPawn = 'P'; + } + + // en-passant moves + if (verticalPosition == enPassantRow) + { + uint8_t enPassantColumn = board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] & 0x0f; + uint8_t column = pieceSquare % 8; + + for (int8_t offset = -1; offset < 2; offset += 2) + if ((enPassantColumn == column + offset) && + (board[pieceSquare + offset] == enemyPawn)) + { + SCL_squareSetAdd(result,pieceSquare + pawnOffset + offset); + break; + } + } + + #undef checkDiagonal + } + break; + + case 'r': // rook + case 'R': + case 'b': // bishop + case 'B': + case 'q': // queen + case 'Q': + { + const int8_t offsets[8] = {-8, 1, 8, -1, -7, 9, -9, 7}; + const int8_t columnDirs[8] = { 0, 1, 0, -1, 1, 1, -1,-1}; + + uint8_t from = (piece == 'b' || piece == 'B') * 4; + uint8_t to = 4 + (piece != 'r' && piece != 'R') * 4; + + for (uint8_t i = from; i < to; ++i) + { + int8_t offset = offsets[i]; + int8_t columnDir = columnDirs[i]; + int8_t square = pieceSquare; + int8_t col = horizontalPosition; + + while (1) + { + square += offset; + col += columnDir; + + if (square < 0 || square > 63 || col < 0 || col > 7) + break; + + char squareC = board[square]; + + if (squareC == '.') + SCL_squareSetAdd(result,square); + else + { + if (SCL_pieceIsWhite(squareC) != isWhite) + SCL_squareSetAdd(result,square); + + break; + } + } + } + } + break; + + case 'n': // knight + case 'N': + { + const int8_t offsets[4] = {6, 10, 15, 17}; + const int8_t columnsMinus[4] = {2,-2,1,-1}; + const int8_t columnsPlus[4] = {-2,2,-1,1}; + const int8_t *off, *col; + + #define checkOffsets(op,comp,limit,dir)\ + off = offsets;\ + col = columns ## dir;\ + for (uint8_t i = 0; i < 4; ++i, ++off, ++col)\ + {\ + int8_t square = pieceSquare op (*off);\ + if (square comp limit) /* out of board? */\ + break;\ + int8_t horizontalCheck = horizontalPosition + (*col);\ + if (horizontalCheck < 0 || horizontalCheck >= 8)\ + continue;\ + char squareC = board[square];\ + if ((squareC == '.') || (SCL_pieceIsWhite(squareC) != isWhite))\ + SCL_squareSetAdd(result,square);\ + } + + checkOffsets(-,<,0,Minus) + checkOffsets(+,>=,SCL_BOARD_SQUARES,Plus) + + #undef checkOffsets + } + break; + + case 'k': // king + case 'K': + { + uint8_t verticalPosition = pieceSquare / 8; + + uint8_t + u = verticalPosition != 0, + d = verticalPosition != 7, + l = horizontalPosition != 0, + r = horizontalPosition != 7; + + uint8_t square2 = pieceSquare - 9; + + #define checkSquare(cond,add) \ + if (cond && ((board[square2] == '.') || \ + (SCL_pieceIsWhite(board[square2])) != isWhite))\ + SCL_squareSetAdd(result,square2);\ + square2 += add; + + checkSquare(l && u,1) + checkSquare(u,1) + checkSquare(r && u,6) + checkSquare(l,2) + checkSquare(r,6) + checkSquare(l && d,1) + checkSquare(d,1) + checkSquare(r && d,0) + + #undef checkSquare + + // castling: + + if (checkCastling) + { + uint8_t bitShift = 4 + 2 * (!isWhite); + + if ((board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] & (0x03 << bitShift)) && + !SCL_boardSquareAttacked(board,pieceSquare,!isWhite)) // no check? + { +#if !SCL_960_CASTLING + // short castle: + pieceSquare++; + + if ((board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] & (0x01 << bitShift)) && + (board[pieceSquare] == '.') && + (board[pieceSquare + 1] == '.') && + (board[pieceSquare + 2] == SCL_pieceToColor('r',isWhite)) && + !SCL_boardSquareAttacked(board,pieceSquare,!isWhite)) + SCL_squareSetAdd(result,pieceSquare + 1); + + /* note: don't check the final square for check, it will potentially + be removed later (can't end up in check) */ + + // long castle: + pieceSquare -= 2; + + if ((board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] & (0x02 << bitShift)) && + (board[pieceSquare] == '.') && + (board[pieceSquare - 1] == '.') && + (board[pieceSquare - 2] == '.') && + (board[pieceSquare - 3] == SCL_pieceToColor('r',isWhite)) && + !SCL_boardSquareAttacked(board,pieceSquare,!isWhite)) + SCL_squareSetAdd(result,pieceSquare - 1); +#else // 960 castling + for (int i = 0; i < 2; ++i) // short and long + if (board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] & ((i + 1) << bitShift)) + { + uint8_t + rookPos = board[SCL_BOARD_EXTRA_BYTE] >> 3, + targetPos = 5; + + if (i == 1) + { + rookPos = board[SCL_BOARD_EXTRA_BYTE] & 0x07, + targetPos = 3; + } + + if (!isWhite) + { + rookPos += 56; + targetPos += 56; + } + + uint8_t ok = board[rookPos] == SCL_pieceToColor('r',isWhite); + + if (!ok) + continue; + + int8_t inc = 1 - 2 * (targetPos > rookPos); + + while (targetPos != rookPos) // check vacant squares for the rook + { + if (board[targetPos] != '.' && + targetPos != pieceSquare) + { + ok = 0; + break; + } + + targetPos += inc; + } + + if (!ok) + continue; + + targetPos = i == 0 ? 6 : 2; + + if (!isWhite) + targetPos += 56; + + inc = 1 - 2 * (targetPos > pieceSquare); + + while (targetPos != pieceSquare) // check squares for the king + { + if ((board[targetPos] != '.' && + targetPos != rookPos) || + SCL_boardSquareAttacked(board,targetPos,!isWhite)) + { + ok = 0; + break; + } + + targetPos += inc; + } + + if (ok) + SCL_squareSetAdd(result,rookPos); + } +#endif + } + } + } + break; + + default: + break; + } +} + +void SCL_printSquareSet(SCL_SquareSet set, SCL_PutCharFunction putCharFunc) +{ + uint8_t first = 1; + + putCharFunc('('); + + for (uint8_t i = 0; i < SCL_BOARD_SQUARES; ++i) + { + if (!SCL_squareSetContains(set, i)) + continue; + + if (!first) + putCharFunc(','); + else + first = 0; + + putCharFunc('A' + i % 8); + putCharFunc('1' + i / 8); + } + + putCharFunc(')'); +} + +void SCL_printSquareUTF8(uint8_t square, SCL_PutCharFunction putCharFunc) +{ + uint32_t val = 0; + + switch (square) + { + case 'r': val = 0x9c99e200; break; + case 'n': val = 0x9e99e200; break; + case 'b': val = 0x9d99e200; break; + case 'q': val = 0x9b99e200; break; + case 'k': val = 0x9a99e200; break; + case 'p': val = 0x9f99e200; break; + case 'R': val = 0x9699e200; break; + case 'N': val = 0x9899e200; break; + case 'B': val = 0x9799e200; break; + case 'Q': val = 0x9599e200; break; + case 'K': val = 0x9499e200; break; + case 'P': val = 0x9999e200; break; + case '.': val = 0x9296e200; break; + case ',': val = 0x9196e200; break; + default: putCharFunc(square); return; break; + } + + uint8_t count = 4; + + while ((val % 256 == 0) && (count > 0)) + { + val /= 256; + count--; + } + + while (count > 0) + { + putCharFunc(val % 256); + val /= 256; + count--; + } +} + +void SCL_boardGetMoves( + SCL_Board board, + uint8_t pieceSquare, + SCL_SquareSet result) +{ + SCL_SquareSet allMoves; + + SCL_squareSetClear(allMoves); + + for (uint8_t i = 0; i < 8; ++i) + result[i] = 0; + + SCL_boardGetPseudoMoves(board,pieceSquare,1,allMoves); + + // Now only keep moves that don't lead to one's check: + + SCL_SQUARE_SET_ITERATE_BEGIN(allMoves) + + SCL_MoveUndo undo = SCL_boardMakeMove(board,pieceSquare,iteratedSquare,'q'); + + if (!SCL_boardCheck(board,!SCL_boardWhitesTurn(board))) + SCL_squareSetAdd(result,iteratedSquare); + + SCL_boardUndoMove(board,undo); + + SCL_SQUARE_SET_ITERATE_END +} + +uint8_t SCL_boardDead(SCL_Board board) +{ + /* + This byte represents material by bits: + + MSB _ _ _ _ _ _ _ _ LSB + | | | | | \_ white knight + | | | | \__ white bishop on white + | | | \____ white bishop on black + | | \________ black knight + | \__________ black bishop on white + \____________ black bishop on black + */ + uint8_t material = 0; + + const char *p = board; + + for (uint8_t i = 0; i < SCL_BOARD_SQUARES; ++i) + { + char c = *p; + + switch (c) + { + case 'n': material |= 0x01; break; + case 'N': material |= 0x10; break; + case 'b': material |= (0x02 << (!SCL_squareIsWhite(i))); break; + case 'B': material |= (0x20 << (!SCL_squareIsWhite(i))); break; + case 'p': + case 'P': + case 'r': + case 'R': + case 'q': + case 'Q': + return 0; // REMOVE later if more complex check are performed + break; + + default: break; + } + + p++; + } + + // TODO: add other checks than only insufficient material + + // possible combinations of insufficient material: + + return + (material == 0x00) || // king vs king + (material == 0x01) || // king and knight vs king + (material == 0x10) || // king and knight vs king + (material == 0x02) || // king and bishop vs king + (material == 0x20) || // king and bishop vs king + (material == 0x04) || // king and bishop vs king + (material == 0x40) || // king and bishop vs king + (material == 0x22) || // king and bishop vs king and bishop (same color) + (material == 0x44); // king and bishop vs king and bishop (same color) +} + +uint8_t SCL_boardGetPosition(SCL_Board board) +{ + uint8_t check = SCL_boardCheck(board,SCL_boardWhitesTurn(board)); + uint8_t moves = SCL_boardMovePossible(board); + + if (check) + return moves ? SCL_POSITION_CHECK : SCL_POSITION_MATE; + else if (!moves) + return SCL_POSITION_STALEMATE; + + if (SCL_boardDead(board)) + return SCL_POSITION_DEAD; + + return SCL_POSITION_NORMAL; +} + +uint8_t SCL_stringToMove(const char *moveString, uint8_t *resultFrom, + uint8_t *resultTo, char *resultPromotion) +{ + char c; + + uint8_t *dst = resultFrom; + + for (uint8_t i = 0; i < 2; ++i) + { + c = *moveString; + + *dst = (c >= 'a') ? (c - 'a') : (c - 'A'); + + if (*dst > 7) + return 0; + + moveString++; + c = *moveString; + + *dst += 8 * (c - '1'); + + if (*dst > 63) + return 0; + + moveString++; + + dst = resultTo; + } + + c = *moveString; + + if (c < 'A') + c = c - 'A' + 'a'; + + switch (c) + { + case 'N': case 'n': *resultPromotion = 'n'; break; + case 'B': case 'b': *resultPromotion = 'b'; break; + case 'R': case 'r': *resultPromotion = 'r'; break; + case 'Q': case 'q': + default: *resultPromotion = 'q'; break; + } + + return 1; +} + +void SCL_printBoard( + SCL_Board board, + SCL_PutCharFunction putCharFunc, + SCL_SquareSet highlightSquares, + uint8_t selectSquare, + uint8_t format, + uint8_t offset, + uint8_t labels, + uint8_t blackDown) +{ + if (labels) + { + for (uint8_t i = 0; i < offset + 2; ++i) + putCharFunc(' '); + + for (uint8_t i = 0; i < 8; ++i) + { + if ((format != SCL_PRINT_FORMAT_COMPACT) && + (format != SCL_PRINT_FORMAT_COMPACT_UTF8)) + putCharFunc(' '); + + putCharFunc(blackDown ? ('H' - i) : ('A' + i)); + } + + putCharFunc('\n'); + } + + int8_t i = 7; + int8_t add = 1; + + if (!blackDown) + { + i = 56; + add = -1; + } + + for (int8_t row = 0; row < 8; ++row) + { + for (uint8_t j = 0; j < offset; ++j) + putCharFunc(' '); + + if (labels) + { + putCharFunc(!blackDown ? ('8' - row) : ('1' + row)); + putCharFunc(' '); + } + + const char *square = board + i; + + for (int8_t col = 0; col < 8; ++col) + { + switch (format) + { + case SCL_PRINT_FORMAT_COMPACT: + putCharFunc( + (*square == '.') ? ( + ((i != selectSquare) ? + (!SCL_squareSetContains(highlightSquares,i) ? *square : '*') + : '#')) : *square); + break; + + case SCL_PRINT_FORMAT_UTF8: + { + char squareChar = SCL_squareIsWhite(i) ? '.' : ','; + char pieceChar = (*square == '.') ? squareChar : *square; + + if (i == selectSquare) + { + putCharFunc('('); + + if (*square == '.') + putCharFunc(')'); + else + SCL_printSquareUTF8(pieceChar,putCharFunc); + } + else if (!SCL_squareSetContains(highlightSquares,i)) + { + SCL_printSquareUTF8(squareChar,putCharFunc); + SCL_printSquareUTF8(pieceChar,putCharFunc); + } + else + { + putCharFunc('['); + + if (*square == '.') + putCharFunc(']'); + else + SCL_printSquareUTF8(*square,putCharFunc); + } + + break; + } + + case SCL_PRINT_FORMAT_COMPACT_UTF8: + SCL_printSquareUTF8( + (*square == '.') ? ( + SCL_squareSetContains(highlightSquares,i) ? '*' : + (i == selectSquare ? '#' : ((SCL_squareIsWhite(i) ? '.' : ','))) + ) : *square,putCharFunc); + break; + + case SCL_PRINT_FORMAT_NORMAL: + default: + { + uint8_t c = *square; + + char squareColor = SCL_squareIsWhite(i) ? ' ' : ':'; + + putCharFunc((i != selectSquare) ? + (!SCL_squareSetContains(highlightSquares,i) ? + squareColor : '#') : '@'); + + putCharFunc(c == '.' ? squareColor : *square); + break; + } + } + + i -= add; + square -= add; + } + + putCharFunc('\n'); + + i += add * 16; + } // for rows +} + +int16_t SCL_pieceValuePositive(char piece) +{ + switch (piece) + { + case 'p': + case 'P': return SCL_VALUE_PAWN; break; + case 'n': + case 'N': return SCL_VALUE_KNIGHT; break; + case 'b': + case 'B': return SCL_VALUE_BISHOP; break; + case 'r': + case 'R': return SCL_VALUE_ROOK; break; + case 'q': + case 'Q': return SCL_VALUE_QUEEN; break; + case 'k': + case 'K': return SCL_VALUE_KING; break; + default: break; + } + + return 0; +} + +int16_t SCL_pieceValue(char piece) +{ + switch (piece) + { + case 'P': return SCL_VALUE_PAWN; break; + case 'N': return SCL_VALUE_KNIGHT; break; + case 'B': return SCL_VALUE_BISHOP; break; + case 'R': return SCL_VALUE_ROOK; break; + case 'Q': return SCL_VALUE_QUEEN; break; + case 'K': return SCL_VALUE_KING; break; + case 'p': return -1 * SCL_VALUE_PAWN; break; + case 'n': return -1 * SCL_VALUE_KNIGHT; break; + case 'b': return -1 * SCL_VALUE_BISHOP; break; + case 'r': return -1 * SCL_VALUE_ROOK; break; + case 'q': return -1 * SCL_VALUE_QUEEN; break; + case 'k': return -1 * SCL_VALUE_KING; break; + default: break; + } + + return 0; +} + +#define ATTACK_BONUS 3 +#define MOBILITY_BONUS 10 +#define CENTER_BONUS 7 +#define CHECK_BONUS 5 +#define KING_CASTLED_BONUS 30 +#define KING_BACK_BONUS 15 +#define KING_NOT_CENTER_BONUS 15 +#define PAWN_NON_DOUBLE_BONUS 3 +#define PAWN_PAIR_BONUS 3 +#define KING_CENTERNESS 10 + +int16_t _SCL_rateKingEndgamePosition(uint8_t position) +{ + int16_t result = 0; + uint8_t rank = position / 8; + position %= 8; + + if (position > 1 && position < 6) + result += KING_CENTERNESS; + + if (rank > 1 && rank < 6) + result += KING_CENTERNESS; + + return result; +} + +int16_t SCL_boardEvaluateStatic(SCL_Board board) +{ + uint8_t position = SCL_boardGetPosition(board); + + int16_t total = 0; + + switch (position) + { + case SCL_POSITION_MATE: + return SCL_boardWhitesTurn(board) ? + -1 * SCL_EVALUATION_MAX_SCORE : SCL_EVALUATION_MAX_SCORE; + break; + + case SCL_POSITION_STALEMATE: + case SCL_POSITION_DEAD: + return 0; + break; + + /* + main points are assigned as follows: + - points for material as a sum of all material on board + - for playing side: if a piece attacks piece of greater value, a fraction + of the value difference is gained (we suppose exchange), this is only + gained once per every attacking piece (maximum gain is taken), we only + take fraction so that actually taking the piece is favored + - ATTACK_BONUS points for any attacked piece + + other points are assigned as follows (in total these shouldn't be more + than the value of one pawn) + - mobility: MOBILITY_BONUS points for each piece with at least 4 possible + moves + - center control: CENTER_BONUS points for a piece on a center square + - CHECK_BONUS points for check + - king: + - safety (non endgame): KING_BACK_BONUS points for king on staring rank, + additional KING_CASTLED_BONUS if the kind if on castled square or + closer to the edge, additional KING_NOT_CENTER_BONUS for king not on + its start neighbouring center square + - center closeness (endgame): up to 2 * KING_CENTERNESS points for + being closer to center + - non-doubled pawns: PAWN_NON_DOUBLE_BONUS points for each pawn without + same color pawn directly in front of it + - pawn structure: PAWN_PAIR_BONUS points for each pawn guarding own pawn + - advancing pawns: 1 point for each pawn's rank in its move + direction + */ + + case SCL_POSITION_CHECK: + total += SCL_boardWhitesTurn(board) ? -1 * CHECK_BONUS : CHECK_BONUS; + // intentional fallthrough + case SCL_POSITION_NORMAL: + default: + { + SCL_SquareSet moves; + + const char *p = board; + + int16_t positiveMaterial = 0; + uint8_t endgame = 0; + + // first count material to see if this is endgame or not + for (uint8_t i = 0; i < SCL_BOARD_SQUARES; ++i, ++p) + { + char s = *p; + + if (s != '.') + { + positiveMaterial += SCL_pieceValuePositive(s); + total += SCL_pieceValue(s); + } + } + + endgame = positiveMaterial <= SCL_ENDGAME_MATERIAL_LIMIT; + + p = board; + + for (uint8_t i = 0; i < SCL_BOARD_SQUARES; ++i, ++p) + { + char s = *p; + + if (s != '.') + { + uint8_t white = SCL_pieceIsWhite(s); + + switch (s) + { + case 'k': // king safety + if (endgame) + total -= _SCL_rateKingEndgamePosition(i); + else if (i >= 56) + { + total -= KING_BACK_BONUS; + + if (i != 59) + { + total -= KING_NOT_CENTER_BONUS; + + if (i >= 62 || i <= 58) + total -= KING_CASTLED_BONUS; + } + } + break; + + case 'K': + if (endgame) + total += _SCL_rateKingEndgamePosition(i); + else if (i <= 7) + { + total += KING_BACK_BONUS; + + if (i != 3) + { + total += KING_NOT_CENTER_BONUS; + + if (i <= 2 || i >= 6) + total += KING_CASTLED_BONUS; + } + } + break; + + case 'P': // pawns + case 'p': + { + int8_t rank = i / 8; + + if (rank != 0 && rank != 7) + { + if (s == 'P') + { + total += rank; + + char *tmp = board + i + 8; + + if (*tmp != 'P') + total += PAWN_NON_DOUBLE_BONUS; + + if (i % 8 != 7) + { + tmp++; + + if (*tmp == 'P') + total += PAWN_PAIR_BONUS; + + if (*(tmp - 16) == 'P') + total += PAWN_PAIR_BONUS; + } + } + else + { + total -= 7 - rank; + + char *tmp = board + i - 8; + + if (*tmp != 'p') + total -= PAWN_NON_DOUBLE_BONUS; + + if (i % 8 != 7) + { + tmp += 17; + + if (*tmp == 'p') + total -= PAWN_PAIR_BONUS; + + if (*(tmp - 16) == 'p') + total -= PAWN_PAIR_BONUS; + } + } + } + + break; + } + + default: break; + } + + if (i >= 27 && i <= 36 && (i >= 35 || i <= 28)) // center control + total += white ? CENTER_BONUS : (-1 * CENTER_BONUS); + + // for performance we only take pseudo moves + SCL_boardGetPseudoMoves(board,i,0,moves); + + if (SCL_squareSetSize(moves) >= 4) // mobility + total += white ? + MOBILITY_BONUS : (-1 * MOBILITY_BONUS); + + int16_t exchangeBonus = 0; + + SCL_SQUARE_SET_ITERATE_BEGIN(moves) + + if (board[iteratedSquare] != '.') + { + total += white ? + ATTACK_BONUS : (- 1 * ATTACK_BONUS); + + if (SCL_boardWhitesTurn(board) == white) + { + int16_t valueDiff = + SCL_pieceValuePositive(board[iteratedSquare]) - + SCL_pieceValuePositive(s); + + valueDiff /= 4; // only take a fraction to favor taking + + if (valueDiff > exchangeBonus) + exchangeBonus = valueDiff; + } + } + + SCL_SQUARE_SET_ITERATE_END + + if (exchangeBonus != 0) + total += white ? exchangeBonus : -1 * exchangeBonus; + } + } // for each square + + return total; + + break; + + } // normal position + } // switch + + return 0; +} + +#undef ATTACK_BONUS +#undef MOBILITY_BONUS +#undef CENTER_BONUS +#undef CHECK_BONUS +#undef KING_CASTLED_BONUS +#undef KING_BACK_BONUS +#undef PAWN_NON_DOUBLE_BONUS +#undef PAWN_PAIR_BONUS +#undef KING_CENTERNESS + +SCL_StaticEvaluationFunction _SCL_staticEvaluationFunction; +int16_t _SCL_currentEval; +int8_t _SCL_depthHardLimit; + +/** + Inner recursive function for SCL_boardEvaluateDynamic. It is passed a square + (or -1) at which last capture happened, to implement capture extension. +*/ +int16_t _SCL_boardEvaluateDynamic(SCL_Board board, int8_t depth, + int16_t alphaBeta, int8_t takenSquare) +{ +#if SCL_COUNT_EVALUATED_POSITIONS + SCL_positionsEvaluated++; +#endif + +#if SCL_CALL_WDT_RESET + wdt_reset(); +#endif + + uint8_t whitesTurn = SCL_boardWhitesTurn(board); + int8_t valueMultiply = whitesTurn ? 1 : -1; + int16_t bestMoveValue = -1 * SCL_EVALUATION_MAX_SCORE; + uint8_t shouldCompute = depth > 0; + uint8_t extended = 0; + uint8_t positionType = SCL_boardGetPosition(board); + + if (!shouldCompute) + { + /* here we do two extensions (deeper search): taking on a same square + (exchanges) and checks (good for mating and preventing mates): */ + extended = + (depth > _SCL_depthHardLimit) && + (takenSquare >= 0 || + (SCL_boardGetPosition(board) == SCL_POSITION_CHECK)); + + shouldCompute = extended; + } + +#if SCL_DEBUG_AI + char moveStr[8]; + uint8_t debugFirst = 1; +#endif + + if (shouldCompute && + (positionType == SCL_POSITION_NORMAL || positionType == SCL_POSITION_CHECK)) + { +#if SCL_DEBUG_AI + putchar('('); +#endif + + alphaBeta *= valueMultiply; + uint8_t end = 0; + const char *b = board; + + depth--; + + for (uint8_t i = 0; i < SCL_BOARD_SQUARES; ++i, ++b) + { + char s = *b; + + if (s != '.' && SCL_pieceIsWhite(s) == whitesTurn) + { + SCL_SquareSet moves; + + SCL_squareSetClear(moves); + + SCL_boardGetMoves(board,i,moves); + + if (!SCL_squareSetEmpty(moves)) + { + SCL_SQUARE_SET_ITERATE_BEGIN(moves) + + int8_t captureExtension = -1; + + if (board[iteratedSquare] != '.' && // takes a piece + (takenSquare == -1 || // extend on first taken sq. + (extended && takenSquare != -1) || // ignore check extension + (iteratedSquare == takenSquare))) // extend on same sq. taken + captureExtension = iteratedSquare; + + SCL_MoveUndo undo = SCL_boardMakeMove(board,i,iteratedSquare,'q'); + + uint8_t s0Dummy, s1Dummy; + char pDummy; + + SCL_UNUSED(s0Dummy); + SCL_UNUSED(s1Dummy); + SCL_UNUSED(pDummy); + +#if SCL_DEBUG_AI + if (debugFirst) + debugFirst = 0; + else + putchar(','); + + if (extended) + putchar('*'); + + printf("%s ",SCL_moveToString(board,i,iteratedSquare,'q',moveStr)); +#endif + + int16_t value = _SCL_boardEvaluateDynamic( + board, + depth, // this is depth - 1, we decremented it +#if SCL_ALPHA_BETA + valueMultiply * bestMoveValue, +#else + 0, +#endif + captureExtension + ) * valueMultiply; + + SCL_boardUndoMove(board,undo); + + if (value > bestMoveValue) + { + bestMoveValue = value; + +#if SCL_ALPHA_BETA + // alpha-beta pruning: + + if (value > alphaBeta) // no, >= can't be here + { + end = 1; + iterationEnd = 1; + } +#endif + } + + SCL_SQUARE_SET_ITERATE_END + } // !squre set empty? + } // valid piece? + + if (end) + break; + + } // for each square + +#if SCL_DEBUG_AI + putchar(')'); +#endif + } + else // don't dive recursively, evaluate statically + { + bestMoveValue = valueMultiply * + #ifndef SCL_EVALUATION_FUNCTION + _SCL_staticEvaluationFunction(board); + #else + SCL_EVALUATION_FUNCTION(board); + #endif + + /* For stalemate return the opposite value of the board, i.e. if the + position is good for white, then stalemate is good for black and vice + versa. */ + if (positionType == SCL_POSITION_STALEMATE) + bestMoveValue *= -1; + } + + /* Here we either improve (if the move worsens the situation) or devalve (if + it improves the situation) the result: this needs to be done so that good + moves far away are seen as worse compared to equally good moves achieved + in fewer moves. Without this an AI in winning situation may just repeat + random moves and draw by repetition even if it has mate in 1 (it sees all + moves as leading to mate). */ + bestMoveValue += bestMoveValue > _SCL_currentEval * valueMultiply ? -1 : 1; + +#if SCL_DEBUG_AI + printf("%d",bestMoveValue * valueMultiply); +#endif + + return bestMoveValue * valueMultiply; +} + +int16_t SCL_boardEvaluateDynamic(SCL_Board board, uint8_t baseDepth, + uint8_t extensionExtraDepth, SCL_StaticEvaluationFunction evalFunction) +{ + _SCL_staticEvaluationFunction = evalFunction; + _SCL_currentEval = evalFunction(board); + _SCL_depthHardLimit = 0; + _SCL_depthHardLimit -= extensionExtraDepth; + + return _SCL_boardEvaluateDynamic( + board, + baseDepth, + SCL_boardWhitesTurn(board) ? + SCL_EVALUATION_MAX_SCORE : (-1 * SCL_EVALUATION_MAX_SCORE),-1); +} + +void SCL_boardRandomMove(SCL_Board board, SCL_RandomFunction randFunc, + uint8_t *squareFrom, uint8_t *squareTo, char *resultProm) +{ + *resultProm = (randFunc() < 128) ? + ((randFunc() < 128) ? 'r' : 'n') : + ((randFunc() < 128) ? 'b' : 'q'); + + SCL_SquareSet set; + uint8_t white = SCL_boardWhitesTurn(board); + const char *s = board; + + SCL_squareSetClear(set); + + // find squares with pieces that have legal moves + + for (uint8_t i = 0; i < SCL_BOARD_SQUARES; ++i, ++s) + { + char c = *s; + + if (c != '.' && SCL_pieceIsWhite(c) == white) + { + SCL_SquareSet moves; + + SCL_boardGetMoves(board,i,moves); + + if (SCL_squareSetSize(moves) != 0) + SCL_squareSetAdd(set,i); + } + } + + *squareFrom = SCL_squareSetGetRandom(set,randFunc); + + SCL_boardGetMoves(board,*squareFrom,set); + + *squareTo = SCL_squareSetGetRandom(set,randFunc); +} + +void SCL_printBoardSimple( + SCL_Board board, + SCL_PutCharFunction putCharFunc, + uint8_t selectSquare, + uint8_t format) +{ + SCL_SquareSet s; + + SCL_squareSetClear(s); + + SCL_printBoard(board,putCharFunc,s,selectSquare,format,1,1,0); +} + +int16_t SCL_getAIMove( + SCL_Board board, + uint8_t baseDepth, + uint8_t extensionExtraDepth, + uint8_t endgameExtraDepth, + SCL_StaticEvaluationFunction evalFunc, + SCL_RandomFunction randFunc, + uint8_t randomness, + uint8_t repetitionMoveFrom, + uint8_t repetitionMoveTo, + uint8_t *resultFrom, + uint8_t *resultTo, + char *resultProm) +{ +#if SCL_DEBUG_AI + puts("===== AI debug ====="); + putchar('('); + unsigned char debugFirst = 1; + char moveStr[8]; +#endif + + if (baseDepth == 0) + { + SCL_boardRandomMove(board,randFunc,resultFrom,resultTo,resultProm); +#ifndef SCL_EVALUATION_FUNCTION + return evalFunc(board); +#else + return SCL_EVALUATION_FUNCTION(board); +#endif + } + + if (SCL_boardEstimatePhase(board) == SCL_PHASE_ENDGAME) + baseDepth += endgameExtraDepth; + + *resultFrom = 0; + *resultTo = 0; + *resultProm = 'q'; + + int16_t bestScore = + SCL_boardWhitesTurn(board) ? + -1 * SCL_EVALUATION_MAX_SCORE - 1 : (SCL_EVALUATION_MAX_SCORE + 1); + + for (uint8_t i = 0; i < SCL_BOARD_SQUARES; ++i) + if (board[i] != '.' && + SCL_boardWhitesTurn(board) == SCL_pieceIsWhite(board[i])) + { + SCL_SquareSet moves; + + SCL_squareSetClear(moves); + + SCL_boardGetMoves(board,i,moves); + + SCL_SQUARE_SET_ITERATE_BEGIN(moves) + + int16_t score = 0; + +#if SCL_DEBUG_AI + if (debugFirst) + debugFirst = 0; + else + putchar(','); + +printf("%s ",SCL_moveToString( +board,i,iteratedSquare,'q',moveStr)); + +#endif + + if (i != repetitionMoveFrom || iteratedSquare != repetitionMoveTo) + { + SCL_MoveUndo undo = SCL_boardMakeMove(board,i,iteratedSquare,'q'); + + score = SCL_boardEvaluateDynamic(board,baseDepth - 1, + extensionExtraDepth,evalFunc); + + SCL_boardUndoMove(board,undo); + } + + if (randFunc != 0 && + randomness > 1 && + score < 16000 && + score > -16000) + { + /*^ We limit randomizing by about half the max score for two reasons: + to prevent over/under flows and secondly we don't want to alter + the highest values for checkmate -- these are modified by tiny + values depending on their depth so as to prevent endless loops in + which most moves are winning, biasing such values would completely + kill that algorithm */ + + int16_t bias = randFunc(); + bias = (bias - 128) / 2; + bias *= randomness - 1; + score += bias; + } + + uint8_t comparison = + score == bestScore; + + if ((comparison != 1) && + ( + (SCL_boardWhitesTurn(board) && score > bestScore) || + (!SCL_boardWhitesTurn(board) && score < bestScore) + )) + comparison = 2; + + uint8_t replace = 0; + + if (randFunc == 0) + replace = comparison == 2; + else + replace = (comparison == 2) || + ((comparison == 1) && (randFunc() < 160)); // not uniform distr. but simple + + if (replace) + { + *resultFrom = i; + *resultTo = iteratedSquare; + bestScore = score; + } + + SCL_SQUARE_SET_ITERATE_END + } + +#if SCL_DEBUG_AI + printf(")%d %s\n",bestScore,SCL_moveToString(board,*resultFrom,*resultTo,'q',moveStr)); + puts("===== AI debug end ===== "); +#endif + + return bestScore; +} + +uint8_t SCL_boardToFEN(SCL_Board board, char *string) +{ + uint8_t square = 56; + uint8_t spaces = 0; + uint8_t result = 0; + + #define put(c) { *string = (c); string++; result++; } + + while (1) // pieces + { + char s = board[square]; + + if (s == '.') + { + spaces++; + } + else + { + if (spaces != 0) + { + put('0' + spaces) + spaces = 0; + } + + put(s) + } + + square++; + + if (square % 8 == 0) + { + if (spaces != 0) + { + put('0' + spaces) + spaces = 0; + } + + if (square == 8) + break; + + put('/'); + + square -= 16; + } + } + + put(' '); + put(SCL_boardWhitesTurn(board) ? 'w' : 'b'); + put(' '); + + uint8_t b = board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] & 0xf0; + + if (b != 0) // castling + { + if (b & 0x10) put('K'); + if (b & 0x20) put('Q'); + if (b & 0x40) put('k'); + if (b & 0x80) put('q'); + } + else + put('-'); + + put(' '); + + b = board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] & 0x0f; + + if (b < 8) + { + put('a' + b); + put(SCL_boardWhitesTurn(board) ? '6' : '3'); + } + else + put('-'); + + for (uint8_t i = 0; i < 2; ++i) + { + put(' '); + + uint8_t moves = i == 0 ? + ((uint8_t) board[SCL_BOARD_MOVE_COUNT_BYTE]) : + (((uint8_t) board[SCL_BOARD_PLY_BYTE]) / 2 + 1); + + uint8_t hundreds = moves / 100; + uint8_t tens = (moves % 100) / 10; + + if (hundreds != 0) + { + put('0' + hundreds); + put('0' + tens); + } + else if (tens != 0) + put('0' + tens); + + put('0' + moves % 10); + + } + + *string = 0; // terminate the string + + return result + 1; + + #undef put +} + +uint8_t SCL_boardFromFEN(SCL_Board board, const char *string) +{ + uint8_t square = 56; + + while (1) + { + char c = *string; + + if (c == 0) + return 0; + + if (c != '/' && c != ' ') // ignore line separators + { + if (c < '9') // empty square sequence + { + while (c > '0') + { + board[square] = '.'; + square++; + c--; + } + } + else // piece + { + board[square] = c; + square++; + } + } + else + { + if (square == 8) + break; + + square -= 16; + } + + string++; + } + +#define nextChar string++; if (*string == 0) return 0; + + nextChar // space + + board[SCL_BOARD_PLY_BYTE] = *string == 'b'; + nextChar + + nextChar // space + + uint8_t castleEnPassant = 0x0; + + while (*string != ' ') + { + switch (*string) + { + case 'K': castleEnPassant |= 0x10; break; + case 'Q': castleEnPassant |= 0x20; break; + case 'k': castleEnPassant |= 0x40; break; + case 'q': castleEnPassant |= 0x80; break; + default: castleEnPassant |= 0xf0; break; // for partial XFEN compat. + } + + nextChar + } + + nextChar // space + + if (*string != '-') + { + castleEnPassant |= *string - 'a'; + nextChar + } + else + castleEnPassant |= 0x0f; + + nextChar + + board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] = castleEnPassant; + + for (uint8_t i = 0; i < 2; ++i) + { + nextChar // space + + uint8_t ply = 0; + + while (1) + { + char c = *string; + + if (c < '0' || c > '9') + break; + + ply = ply * 10 + (c - '0'); + + string++; + } + + if (i == 0 && *string == 0) + return 0; + + if (i == 0) + board[SCL_BOARD_MOVE_COUNT_BYTE] = ply; + else + board[SCL_BOARD_PLY_BYTE] += (ply - 1) * 2; + } + +#if SCL_960_CASTLING + _SCL_board960RememberRookPositions(board); +#endif + + return 1; +#undef nextChar +} + +uint8_t SCL_boardEstimatePhase(SCL_Board board) +{ + uint16_t totalMaterial = 0; + + uint8_t ply = board[SCL_BOARD_PLY_BYTE]; + + for (uint8_t i = 0; i < SCL_BOARD_SQUARES; ++i) + { + char s = *board; + + if (s != '.') + { + int16_t v = SCL_pieceValue(s); + + if (!SCL_pieceIsWhite(s)) + v *= -1; + + totalMaterial += v; + } + + board++; + } + + if (totalMaterial < SCL_ENDGAME_MATERIAL_LIMIT) + return SCL_PHASE_ENDGAME; + + if (ply <= 10 && (totalMaterial >= SCL_START_MATERIAL - 3 * SCL_VALUE_PAWN)) + return SCL_PHASE_OPENING; + + return SCL_PHASE_MIDGAME; +} + +#define SCL_IMAGE_COUNT 12 + +static const uint8_t SCL_images[8 * SCL_IMAGE_COUNT] = +{ + 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff, + 0xff,0x81,0xff,0xff,0xff,0xff,0xff,0x81,0xff,0xff,0xff,0xff, + 0xff,0x81,0xe7,0xf7,0xf7,0xaa,0xff,0xbd,0xe7,0xf7,0xf7,0xaa, + 0xff,0xc3,0xc3,0xe3,0xc1,0x80,0xff,0x99,0xdb,0xeb,0xc9,0x94, + 0xe7,0xc3,0x81,0xc1,0x94,0x80,0xe7,0xdb,0xbd,0xdd,0xbe,0xbe, + 0xc3,0xc3,0x91,0xe3,0x80,0x80,0xdb,0x99,0x8d,0xeb,0xaa,0xbe, + 0xc3,0x81,0xe1,0xc1,0xc1,0xc1,0xdb,0xbd,0xdd,0xe3,0xdd,0xdd, + 0x81,0x81,0xc1,0x9c,0xc1,0xc1,0x81,0x81,0xc1,0x9c,0xc1,0xc1 +}; + +void SCL_drawBoard( + SCL_Board board, + SCL_PutPixelFunction putPixel, + uint8_t selectedSquare, + SCL_SquareSet highlightSquares, + uint8_t blackDown) +{ + uint8_t row = 0; + uint8_t col = 0; + uint8_t x = 0; + uint8_t y = 0; + uint16_t n = 0; + uint8_t s = 0; + + uint8_t pictureLine = 0; + uint8_t loadLine = 1; + + while (row < 8) + { + if (loadLine) + { + s = blackDown ? (row * 8 + (7 - col)) : ((7 - row) * 8 + col); + + char piece = board[s]; + + if (piece == '.') + pictureLine = (y == 4) ? 0xef : 0xff; + else + { + uint8_t offset = SCL_pieceIsWhite(piece) ? 6 : 0; + piece = SCL_pieceToColor(piece,1); + + switch (piece) + { + case 'R': offset += 1; break; + case 'N': offset += 2; break; + case 'B': offset += 3; break; + case 'K': offset += 4; break; + case 'Q': offset += 5; break; + default: break; + } + + pictureLine = SCL_images[y * SCL_IMAGE_COUNT + offset]; + } + + if (SCL_squareSetContains(highlightSquares,s)) + pictureLine &= (y % 2) ? 0xaa : 0x55; + + if (s == selectedSquare) + pictureLine &= (y == 0 || y == 7) ? 0x00 : ~0x81; + + loadLine = 0; + } + + putPixel(pictureLine & 0x80,n); + pictureLine <<= 1; + + n++; + x++; + + if (x == 8) + { + col++; + loadLine = 1; + x = 0; + } + + if (col == 8) + { + y++; + col = 0; + x = 0; + } + + if (y == 8) + { + row++; + y = 0; + } + } +} + +uint32_t SCL_boardHash32(const SCL_Board board) +{ + uint32_t result = (board[SCL_BOARD_PLY_BYTE] & 0x01) + + (((uint32_t) ((uint8_t) board[SCL_BOARD_ENPASSANT_CASTLE_BYTE])) << 24) + + board[SCL_BOARD_MOVE_COUNT_BYTE]; + + const char *b = board; + + for (uint8_t i = 0; i < SCL_BOARD_SQUARES; ++i, ++b) + { + switch (*b) + { +#define C(p,n) case p: result ^= (i + 1) * n; break; + // the below number are primes + C('P',4003) + C('R',84673) + C('N',93911) + C('B',999331) + C('Q',909091) + C('K',2796203) + C('p',4793) + C('r',19391) + C('n',391939) + C('b',108301) + C('q',174763) + C('k',2474431) +#undef C + default: break; + } + } + + // for extra spread of values we swap the low/high parts: + result = (result >> 16) | (result << 16); + + return result; +} + +void SCL_boardDisableCastling(SCL_Board board) +{ + board[SCL_BOARD_ENPASSANT_CASTLE_BYTE] &= 0x0f; +} + +uint8_t SCL_boardMoveResetsCount(SCL_Board board, + uint8_t squareFrom, uint8_t squareTo) +{ + return board[squareFrom] == 'P' || board[squareFrom] == 'p' || + board[squareTo] != '.'; +} + +void SCL_printPGN(SCL_Record r, SCL_PutCharFunction putCharFunc, + SCL_Board initialState) +{ + if (SCL_recordLength(r) == 0) + return; + + uint16_t pos = 0; + + SCL_Board board; + + if (initialState != 0) + for (uint8_t i = 0; i < SCL_BOARD_STATE_SIZE; ++i) + board[i] = initialState[i]; + else + SCL_boardInit(board); + + while (1) + { + uint8_t s0, s1; + char p; + + uint8_t state = SCL_recordGetMove(r,pos,&s0,&s1,&p); + + pos++; + + if (pos % 2) + { + uint8_t move = pos / 2 + 1; + + if (move / 100 != 0) + putCharFunc('0' + move / 100); + + if (move / 10 != 0 || move / 100 != 0) + putCharFunc('0' + (move % 100) / 10); + + putCharFunc('0' + move % 10); + + putCharFunc('.'); + putCharFunc(' '); + } + +#if !SCL_960_CASTLING + if ((board[s0] == 'K' && s0 == 4 && (s1 == 2 || s1 == 6)) || + (board[s0] == 'k' && s0 == 60 && (s1 == 62 || s1 == 58))) +#else + if ((board[s0] == 'K' && board[s1] == 'R') || + (board[s0] == 'k' && board[s1] == 'r')) +#endif + { + putCharFunc('O'); + putCharFunc('-'); + putCharFunc('O'); + +#if !SCL_960_CASTLING + if (s1 == 58 || s1 == 2) +#else + if ((s1 == (board[SCL_BOARD_EXTRA_BYTE] & 0x07)) || + (s1 == 56 + (board[SCL_BOARD_EXTRA_BYTE] & 0x07))) +#endif + { + putCharFunc('-'); + putCharFunc('O'); + } + } + else + { + uint8_t pawn = board[s0] == 'P' || board[s0] == 'p'; + + if (!pawn) + { + putCharFunc(SCL_pieceToColor(board[s0],1)); + + // disambiguation: + + uint8_t specify = 0; + + for (int i = 0; i < SCL_BOARD_SQUARES; ++i) + if (i != s0 && board[i] == board[s0]) + { + SCL_SquareSet s; + + SCL_squareSetClear(s); + + SCL_boardGetMoves(board,i,s); + + if (SCL_squareSetContains(s,s1)) + specify |= (s0 % 8 != s1 % 8) ? 1 : 2; + } + + if (specify & 0x01) + putCharFunc('a' + s0 % 8); + + if (specify & 0x02) + putCharFunc('1' + s0 / 8); + } + + if (board[s1] != '.' || + (pawn && s0 % 8 != s1 % 8 && board[s1] == '.')) // capture? + { + if (pawn) + putCharFunc('a' + s0 % 8); + + putCharFunc('x'); + } + + putCharFunc('a' + s1 % 8); + putCharFunc('1' + s1 / 8); + + if (pawn && (s1 >= 56 || s1 <= 7)) // promotion? + { + putCharFunc('='); + putCharFunc(SCL_pieceToColor(p,1)); + } + } + + SCL_boardMakeMove(board,s0,s1,p); + + uint8_t position = SCL_boardGetPosition(board); + + if (position == SCL_POSITION_CHECK) + putCharFunc('+'); + + if (position == SCL_POSITION_MATE) + { + putCharFunc('#'); + break; + } + else if (state != SCL_RECORD_CONT) + { + putCharFunc('*'); + break; + } + + putCharFunc(' '); + } +} + +void SCL_recordCopy(SCL_Record recordFrom, SCL_Record recordTo) +{ + for (uint16_t i = 0; i < SCL_RECORD_MAX_SIZE; ++i) + recordTo[i] = recordFrom[i]; +} + +void SCL_gameInit(SCL_Game *game, const SCL_Board startState) +{ + game->startState = startState; + + if (startState != 0) + SCL_boardCopy(startState,game->board); + else + SCL_boardInit(game->board); + + SCL_recordInit(game->record); + + for (uint8_t i = 0; i < 14; ++i) + game->prevMoves[i] = 0; + + game->state = SCL_GAME_STATE_PLAYING; + game->ply = 0; + + SCL_recordInit(game->record); +} + +uint8_t SCL_gameGetRepetiotionMove(SCL_Game *game, + uint8_t *squareFrom, uint8_t *squareTo) +{ + if (squareFrom != 0 && squareTo != 0) + { + *squareFrom = 0; + *squareTo = 0; + } + + /* pos. 1st 2nd 3rd + | | | + v v v + 01 23 45 67 89 AB CD EF + move ab cd ba dc ab cd ba dc */ + + if (game->ply >= 7 && + game->prevMoves[0] == game->prevMoves[5] && + game->prevMoves[0] == game->prevMoves[8] && + game->prevMoves[0] == game->prevMoves[13] && + + game->prevMoves[1] == game->prevMoves[4] && + game->prevMoves[1] == game->prevMoves[9] && + game->prevMoves[1] == game->prevMoves[12] && + + game->prevMoves[2] == game->prevMoves[7] && + game->prevMoves[2] == game->prevMoves[10] && + + game->prevMoves[3] == game->prevMoves[6] && + game->prevMoves[3] == game->prevMoves[11] + ) + { + if (squareFrom != 0 && squareTo != 0) + { + *squareFrom = game->prevMoves[3]; + *squareTo = game->prevMoves[2]; + } + + return 1; + } + + return 0; +} + +void SCL_gameMakeMove(SCL_Game *game, uint8_t squareFrom, uint8_t squareTo, + char promoteTo) +{ + uint8_t repetitionS0, repetitionS1; + + SCL_gameGetRepetiotionMove(game,&repetitionS0,&repetitionS1); + SCL_boardMakeMove(game->board,squareFrom,squareTo,promoteTo); + SCL_recordAdd(game->record,squareFrom,squareTo,promoteTo,SCL_RECORD_CONT); + // ^ TODO: SCL_RECORD_CONT + + game->ply++; + + for (uint8_t i = 0; i < 14 - 2; ++i) + game->prevMoves[i] = game->prevMoves[i + 2]; + + game->prevMoves[12] = squareFrom; + game->prevMoves[13] = squareTo; + + if (squareFrom == repetitionS0 && squareTo == repetitionS1) + game->state = SCL_GAME_STATE_DRAW_REPETITION; + else if (game->board[SCL_BOARD_MOVE_COUNT_BYTE] >= 50) + game->state = SCL_GAME_STATE_DRAW_50; + else + { + uint8_t position = SCL_boardGetPosition(game->board); + + switch (position) + { + case SCL_POSITION_MATE: + game->state = SCL_boardWhitesTurn(game->board) ? + SCL_GAME_STATE_BLACK_WIN : SCL_GAME_STATE_WHITE_WIN; + break; + + case SCL_POSITION_STALEMATE: + game->state = SCL_GAME_STATE_DRAW_STALEMATE; + break; + + case SCL_POSITION_DEAD: + game->state = SCL_GAME_STATE_DRAW_DEAD; + break; + + default: break; + } + } +} + +uint8_t SCL_gameUndoMove(SCL_Game *game) +{ + if (game->ply == 0) + return 0; + + if ((game->ply - 1) > SCL_recordLength(game->record)) + return 0; // can't undo, lacking record + + SCL_Record r; + + SCL_recordCopy(game->record,r); + + uint16_t applyMoves = game->ply - 1; + + SCL_gameInit(game,game->startState); + + for (uint16_t i = 0; i < applyMoves; ++i) + { + uint8_t s0, s1; + char p; + + SCL_recordGetMove(r,i,&s0,&s1,&p); + SCL_gameMakeMove(game,s0,s1,p); + } + + return 1; +} + +uint8_t SCL_boardMoveIsLegal(SCL_Board board, uint8_t squareFrom, + uint8_t squareTo) +{ + if (squareFrom >= SCL_BOARD_SQUARES || squareTo >= SCL_BOARD_SQUARES) + return 0; + + char piece = board[squareFrom]; + + if ((piece == '.') || + (SCL_boardWhitesTurn(board) != SCL_pieceIsWhite(piece))) + return 0; + + SCL_SquareSet moves; + + SCL_boardGetMoves(board,squareFrom,moves); + + return SCL_squareSetContains(moves,squareTo); +} + +#endif // guard diff --git a/movement/make/Makefile b/movement/make/Makefile index 8d045bf..2116eba 100644 --- a/movement/make/Makefile +++ b/movement/make/Makefile @@ -24,6 +24,7 @@ INCLUDES += \ -I../lib/vsop87/ \ -I../lib/astrolib/ \ -I../lib/morsecalc/ \ + -I../lib/smallchesslib/ \ # If you add any other source files you wish to compile, add them after ../app.c # Note that you will need to add a backslash at the end of any line you wish to continue, i.e. @@ -147,6 +148,7 @@ SRCS += \ ../watch_faces/demo/beeps_face.c \ ../watch_faces/sensor/accel_interrupt_count_face.c \ ../watch_faces/complication/metronome_face.c \ + ../watch_faces/complication/smallchess_face.c \ # New watch faces go above this line. # Leave this line at the bottom of the file; it has all the targets for making your project. diff --git a/movement/movement_faces.h b/movement/movement_faces.h index 1364ca9..630f264 100644 --- a/movement/movement_faces.h +++ b/movement/movement_faces.h @@ -122,6 +122,7 @@ #include "beeps_face.h" #include "accel_interrupt_count_face.h" #include "metronome_face.h" +#include "smallchess_face.h" // New includes go above this line. #endif // MOVEMENT_FACES_H_ diff --git a/movement/watch_faces/complication/smallchess_face.c b/movement/watch_faces/complication/smallchess_face.c new file mode 100644 index 0000000..df70064 --- /dev/null +++ b/movement/watch_faces/complication/smallchess_face.c @@ -0,0 +1,504 @@ +/* + * MIT License + * + * Copyright (c) 2023 Jeremy O'Brien + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in all + * copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include +#include + +#include "smallchesslib.h" + +#include "smallchess_face.h" +#include "watch.h" + +#define PIECE_LIST_END_MARKER 0xff + +int8_t cpu_done_beep[] = {BUZZER_NOTE_C5, 5, BUZZER_NOTE_C6, 5, BUZZER_NOTE_C7, 5, 0}; + +static void smallchess_init_board(smallchess_face_state_t *state) { + SCL_gameInit((SCL_Game *)state->game, 0); + memset(state->moveable_pieces, 0xff, sizeof(state->moveable_pieces)); + memset(state->moveable_dests, 0xff, sizeof(state->moveable_dests)); +} + +void smallchess_face_setup(movement_settings_t *settings, uint8_t watch_face_index, void ** context_ptr) { + (void) settings; + (void) watch_face_index; + if (*context_ptr == NULL) { + *context_ptr = malloc(sizeof(smallchess_face_state_t)); + memset(*context_ptr, 0, sizeof(smallchess_face_state_t)); + + /* now alloc/init the game board */ + smallchess_face_state_t *state = (smallchess_face_state_t *)*context_ptr; + state->game = malloc(sizeof(SCL_Game)); + smallchess_init_board(*context_ptr); + } +} + +void smallchess_face_activate(movement_settings_t *settings, void *context) { + (void) settings; + (void) context; +} + +static void _smallchess_calc_moveable_pieces(smallchess_face_state_t *state) { + int moveable_pieces_idx = 0; + SCL_Game *game = (SCL_Game *)state->game; + for (int i = 0; i < SCL_BOARD_SQUARES; ++i) { + if (game->board[i] != '.' && + SCL_pieceIsWhite(game->board[i]) == SCL_boardWhitesTurn(game->board)) { + SCL_SquareSet moveable_pieces = SCL_SQUARE_SET_EMPTY; + SCL_boardGetMoves(game->board, i, moveable_pieces); + if (SCL_squareSetSize(moveable_pieces) != 0) { + state->moveable_pieces[moveable_pieces_idx] = i; + moveable_pieces_idx++; + } + } + } + state->moveable_pieces[moveable_pieces_idx] = PIECE_LIST_END_MARKER; + state->moveable_pieces_idx = 0; +} + +static void _smallchess_make_ai_move(smallchess_face_state_t *state) { + char ai_from_str[3] = {0}; + char ai_to_str[3] = {0}; + uint8_t rep_from, rep_to; + char ai_prom; + + watch_clear_display(); + watch_start_character_blink('C', 100); + SCL_gameGetRepetiotionMove(state->game, &rep_from, &rep_to); + +#ifndef __EMSCRIPTEN__ + hri_oscctrl_write_OSC16MCTRL_FSEL_bf(OSCCTRL, OSCCTRL_OSC16MCTRL_FSEL_16_Val); +#endif + SCL_getAIMove(state->game, 3, 0, 0, SCL_boardEvaluateStatic, NULL, 0, rep_from, rep_to, &state->ai_from_square, &state->ai_to_square, &ai_prom); +#ifndef __EMSCRIPTEN__ + hri_oscctrl_write_OSC16MCTRL_FSEL_bf(OSCCTRL, OSCCTRL_OSC16MCTRL_FSEL_4_Val); +#endif + + SCL_gameMakeMove(state->game, state->ai_from_square, state->ai_to_square, ai_prom); + watch_stop_blink(); + + watch_buzzer_play_sequence(cpu_done_beep, NULL); + + /* cache the move as a string for SHOW_CPU_MOVE state */ + SCL_squareToString(state->ai_from_square, ai_from_str); + SCL_squareToString(state->ai_to_square, ai_to_str); + snprintf(state->last_move_str, sizeof(state->last_move_str), " %s-%s", ai_from_str, ai_to_str); + + /* now cache the list of legal pieces we can move */ + _smallchess_calc_moveable_pieces(state); +} + +static char _smallchess_make_lowercase(char c) { + if (c < 0x61) + return c + 0x20; + + return c; +} + +static void _smallchess_get_endgame_string(smallchess_face_state_t *state, char *buf, uint8_t len) { + uint8_t endgame_state = ((SCL_Game *)state->game)->state; + uint16_t ply = ((SCL_Game *)state->game)->ply; + + switch (endgame_state) { + case SCL_GAME_STATE_WHITE_WIN: + snprintf(buf, len, "Wh%2dm&ate ", ply); + break; + case SCL_GAME_STATE_BLACK_WIN: + snprintf(buf, len, "bL%2dm&ate ", ply); + break; + case SCL_GAME_STATE_DRAW: + case SCL_GAME_STATE_DRAW_STALEMATE: + case SCL_GAME_STATE_DRAW_REPETITION: + case SCL_GAME_STATE_DRAW_50: + case SCL_GAME_STATE_DRAW_DEAD: + snprintf(buf, len, " %2d Drauu", ply); + break; + default: + snprintf(buf, len, " %2d Error", ply); + break; + } +} + +static void _smallchess_face_update_lcd(smallchess_face_state_t *state) { + uint8_t start_square; + uint8_t end_square; + char start_coord[3] = {0}; + char end_coord[3] = {0}; + char buf[14] = {0}; + + uint16_t ply = ((SCL_Game *)state->game)->ply; + + switch (state->state) { + case SMALLCHESS_MENU_RESUME: + snprintf(buf, sizeof(buf), "SC%2dResume", ply); + break; + case SMALLCHESS_MENU_UNDO: + snprintf(buf, sizeof(buf), "SC%2d Undo ", ply); + break; + case SMALLCHESS_MENU_SHOW_LAST_MOVE: + snprintf(buf, sizeof(buf), "SC%2dShLast", ply); + break; + case SMALLCHESS_MENU_NEW_WHITE: + snprintf(buf, sizeof(buf), "Wh%2dStart ", ply); + break; + case SMALLCHESS_MENU_NEW_BLACK: + snprintf(buf, sizeof(buf), "bL%2dStart ", ply); + break; + case SMALLCHESS_SHOW_CPU_MOVE: + case SMALLCHESS_SHOW_LAST_MOVE: + snprintf(buf, + sizeof(buf), + "%c %2d%s", + _smallchess_make_lowercase(((SCL_Game *)state->game)->board[state->ai_to_square]), + ply, + state->last_move_str); + + break; + case SMALLCHESS_SELECT_PIECE: + if (((SCL_Game *)state->game)->state != SCL_GAME_STATE_PLAYING) { + _smallchess_get_endgame_string(state, buf, sizeof(buf)); + break; + } + start_square = state->moveable_pieces[state->moveable_pieces_idx]; + SCL_squareToString(start_square, start_coord); + snprintf(buf, + sizeof(buf), + "%c %2d %s- ", + _smallchess_make_lowercase(((SCL_Game *)state->game)->board[start_square]), + ply + 1, + start_coord); + break; + case SMALLCHESS_SELECT_DEST: + start_square = state->moveable_pieces[state->moveable_pieces_idx]; + SCL_squareToString(start_square, start_coord); + end_square = state->moveable_dests[state->moveable_dests_idx]; + SCL_squareToString(end_square, end_coord); + snprintf(buf, + sizeof(buf), + "%c %2d %s-%s", + _smallchess_make_lowercase(((SCL_Game *)state->game)->board[start_square]), + ply + 1, + start_coord, + end_coord); + break; + default: + break; + } + + watch_display_string(buf, 0); +} + +static void _smallchess_select_main_menu_subitem(smallchess_face_state_t *state) { + char from_str[3] = {0}; + char to_str[3] = {0}; + char prom; + + switch (state->state) { + case SMALLCHESS_MENU_RESUME: + state->state = SMALLCHESS_SELECT_PIECE; + break; + case SMALLCHESS_MENU_UNDO: + /* undo twice to undo the CPU's move and our move */ + SCL_gameUndoMove((SCL_Game *)state->game); + SCL_gameUndoMove((SCL_Game *)state->game); + /* and re-calculate the moveable pieces for this new state */ + _smallchess_calc_moveable_pieces(state); + break; + case SMALLCHESS_MENU_NEW_WHITE: + SCL_gameInit((SCL_Game *)state->game, 0); + _smallchess_calc_moveable_pieces(state); + state->state = SMALLCHESS_SELECT_PIECE; + break; + case SMALLCHESS_MENU_NEW_BLACK: + SCL_gameInit((SCL_Game *)state->game, 0); + /* force a move since black is playing */ + _smallchess_make_ai_move(state); + state->state = SMALLCHESS_SHOW_CPU_MOVE; + break; + case SMALLCHESS_MENU_SHOW_LAST_MOVE: + /* fetch the move */ + SCL_recordGetMove(((SCL_Game *)state->game)->record, ((SCL_Game *)state->game)->ply - 1, &state->ai_from_square, &state->ai_to_square, &prom); + SCL_squareToString(state->ai_from_square, from_str); + SCL_squareToString(state->ai_to_square, to_str); + snprintf(state->last_move_str, sizeof(state->last_move_str), " %s-%s", from_str, to_str); + state->state = SMALLCHESS_SHOW_LAST_MOVE; + break; + default: + break; + } +} + +static void _smallchess_handle_select_piece_button_event(smallchess_face_state_t *state, movement_event_t event) { + SCL_SquareSet moveable_dests = SCL_SQUARE_SET_EMPTY; + + /* back to main menu on any event when game ends */ + if (((SCL_Game *)state->game)->state != SCL_GAME_STATE_PLAYING) { + state->state = SMALLCHESS_MENU_RESUME; + return; + } + + switch (event.event_type) { + case EVENT_ALARM_BUTTON_UP: + // check for no moves possible state (shouldn't happen but this will prevent weirdness) + if (state->moveable_pieces[0] == PIECE_LIST_END_MARKER) { + return; + } + + state->moveable_pieces_idx += 1; + if (state->moveable_pieces_idx >= NUM_ELEMENTS(state->moveable_pieces)) { + state->moveable_pieces_idx = 0; + } + + if (state->moveable_pieces[state->moveable_pieces_idx] == PIECE_LIST_END_MARKER) { + state->moveable_pieces_idx = 0; + } + break; + case EVENT_LIGHT_BUTTON_UP: + // check for no moves possible state (shouldn't happen but this will prevent weirdness) + if (state->moveable_pieces[0] == PIECE_LIST_END_MARKER) { + return; + } + + /* handle wrap around */ + if (state->moveable_pieces_idx == 0) { + for (unsigned int i = 0; i < NUM_ELEMENTS(state->moveable_pieces); i++) { + if (state->moveable_pieces[i] == 0xff) { + state->moveable_pieces_idx = i - 1; + break; + } + } + } else { + state->moveable_pieces_idx -= 1; + } + break; + case EVENT_LIGHT_LONG_PRESS: + if (((SCL_Game *)state->game)->ply == 0) { + state->state = SMALLCHESS_MENU_NEW_WHITE; + } else { + state->state = SMALLCHESS_MENU_RESUME; + } + break; + case EVENT_ALARM_LONG_PRESS: + /* pre-calculate the possible moves this piece can make */ + SCL_boardGetMoves(((SCL_Game *)state->game)->board, state->moveable_pieces[state->moveable_pieces_idx], moveable_dests); + state->moveable_dests_idx = 0; + SCL_SQUARE_SET_ITERATE_BEGIN(moveable_dests) + state->moveable_dests[state->moveable_dests_idx] = iteratedSquare; + state->moveable_dests_idx++; + SCL_SQUARE_SET_ITERATE_END + state->moveable_dests[state->moveable_dests_idx] = PIECE_LIST_END_MARKER; + state->moveable_dests_idx = 0; + state->state = SMALLCHESS_SELECT_DEST; + default: + break; + } +} + +static void _smallchess_handle_select_dest_button_event(smallchess_face_state_t *state, movement_event_t event) { + switch (event.event_type) { + case EVENT_ALARM_BUTTON_UP: + // check for no moves possible state (shouldn't happen but this will prevent weirdness) + if (state->moveable_dests[0] == PIECE_LIST_END_MARKER) { + return; + } + state->moveable_dests_idx += 1; + if (state->moveable_dests_idx >= (sizeof(state->moveable_dests) / sizeof(state->moveable_dests[0]))) { + state->moveable_dests_idx = 0; + } + + if (state->moveable_dests[state->moveable_dests_idx] == PIECE_LIST_END_MARKER) { + state->moveable_dests_idx = 0; + } + break; + case EVENT_LIGHT_BUTTON_UP: + // check for no moves possible state (shouldn't happen but this will prevent weirdness) + if (state->moveable_dests[0] == PIECE_LIST_END_MARKER) { + return; + } + + /* handle wrap around */ + if (state->moveable_dests_idx == 0) { + for (unsigned int i = 0; i < NUM_ELEMENTS(state->moveable_dests); i++) { + if (state->moveable_dests[i] == 0xff) { + state->moveable_dests_idx = i - 1; + break; + } + } + } else { + state->moveable_dests_idx -= 1; + } + break; + case EVENT_LIGHT_LONG_PRESS: + state->state = SMALLCHESS_SELECT_PIECE; + break; + case EVENT_ALARM_LONG_PRESS: + SCL_gameMakeMove((SCL_Game *)state->game, state->moveable_pieces[state->moveable_pieces_idx], state->moveable_dests[state->moveable_dests_idx], 'q'); + + /* if the player didn't win or draw here, calculate a move */ + if (((SCL_Game *)state->game)->state == SCL_GAME_STATE_PLAYING) { + _smallchess_make_ai_move(state); + state->state = SMALLCHESS_SHOW_CPU_MOVE; + } else { + /* player ended the game through mate or draw; jump to select piece screen to show state */ + state->state = SMALLCHESS_SELECT_PIECE; + } + break; + default: + break; + } +} + +/* this just waits until any button is hit */ +static void _smallchess_handle_show_cpu_move_button_event(smallchess_face_state_t *state, movement_event_t event) { + switch (event.event_type) { + case EVENT_ALARM_BUTTON_UP: + case EVENT_LIGHT_BUTTON_UP: + case EVENT_ALARM_LONG_PRESS: + case EVENT_LIGHT_LONG_PRESS: + state->state = SMALLCHESS_SELECT_PIECE; + break; + default: + break; + } +} + +static void _smallchess_handle_show_last_move_button_event(smallchess_face_state_t *state, movement_event_t event) { + switch (event.event_type) { + case EVENT_ALARM_BUTTON_UP: + case EVENT_LIGHT_BUTTON_UP: + case EVENT_ALARM_LONG_PRESS: + case EVENT_LIGHT_LONG_PRESS: + state->state = SMALLCHESS_MENU_SHOW_LAST_MOVE; + break; + default: + break; + } +} + +static void _smallchess_handle_playing_button_event(smallchess_face_state_t *state, movement_event_t event) { + if (state->state == SMALLCHESS_SELECT_PIECE) { + _smallchess_handle_select_piece_button_event(state, event); + } else if (state->state == SMALLCHESS_SELECT_DEST) { + _smallchess_handle_select_dest_button_event(state, event); + } else if (state->state == SMALLCHESS_SHOW_CPU_MOVE) { + _smallchess_handle_show_cpu_move_button_event(state, event); + } else if (state->state == SMALLCHESS_SHOW_LAST_MOVE) { + _smallchess_handle_show_last_move_button_event(state, event); + } +} + +static void _smallchess_handle_main_menu_button_event(smallchess_face_state_t *state, movement_event_t event) { + uint16_t ply = ((SCL_Game *)state->game)->ply; + + switch (event.event_type) { + case EVENT_ALARM_BUTTON_UP: + /* no game started; only offer start white/start black */ + if (ply == 0) { + if (state->state == SMALLCHESS_MENU_NEW_WHITE) { + state->state = SMALLCHESS_MENU_NEW_BLACK; + } else { + state->state = SMALLCHESS_MENU_NEW_WHITE; + } + } else { + state->state++; + if (state->state >= SMALLCHESS_PLAYING_SPLIT) { + state->state = SMALLCHESS_MENU_RESUME; + } + } + + break; + case EVENT_LIGHT_BUTTON_UP: + /* no game started; only offer start white/start black */ + if (ply == 0) { + if (state->state == SMALLCHESS_MENU_NEW_BLACK) { + state->state = SMALLCHESS_MENU_NEW_WHITE; + } else { + state->state = SMALLCHESS_MENU_NEW_BLACK; + } + } else { + if (state->state == SMALLCHESS_MENU_RESUME) { + state->state = SMALLCHESS_PLAYING_SPLIT - 1; + } else { + state->state--; + } + } + + break; + case EVENT_ALARM_LONG_PRESS: + _smallchess_select_main_menu_subitem(state); + break; + default: + break; + } +} + +static void _smallchess_handle_button_event(smallchess_face_state_t *state, movement_event_t event) { + if (state->state < SMALLCHESS_PLAYING_SPLIT) { + /* in main menu */ + _smallchess_handle_main_menu_button_event(state, event); + } else if (state->state > SMALLCHESS_PLAYING_SPLIT) { + /* in piece selection */ + _smallchess_handle_playing_button_event(state, event); + } +} + +bool smallchess_face_loop(movement_event_t event, movement_settings_t *settings, void *context) { + (void) settings; + smallchess_face_state_t *state = (smallchess_face_state_t *)context; + + switch (event.event_type) { + case EVENT_ACTIVATE: + if (((SCL_Game *)state->game)->ply == 0) { + state->state = SMALLCHESS_MENU_NEW_WHITE; + } else { + state->state = SMALLCHESS_MENU_RESUME; + } + _smallchess_face_update_lcd(state); + break; + case EVENT_LIGHT_BUTTON_UP: + case EVENT_LIGHT_LONG_PRESS: + case EVENT_ALARM_BUTTON_UP: + case EVENT_ALARM_LONG_PRESS: + _smallchess_handle_button_event(state, event); + _smallchess_face_update_lcd(state); + break; + case EVENT_TICK: + break; + case EVENT_TIMEOUT: + break; + case EVENT_LIGHT_BUTTON_DOWN: + break; + default: + movement_default_loop_handler(event, settings); + break; + } + + return true; +} + +void smallchess_face_resign(movement_settings_t *settings, void *context) { + (void) settings; + (void) context; + watch_set_led_off(); +} diff --git a/movement/watch_faces/complication/smallchess_face.h b/movement/watch_faces/complication/smallchess_face.h new file mode 100644 index 0000000..2eb0786 --- /dev/null +++ b/movement/watch_faces/complication/smallchess_face.h @@ -0,0 +1,90 @@ +/* + * MIT License + * + * Copyright (c) 2023 Jeremy O'Brien + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in all + * copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#ifndef SMALLCHESS_FACE_H_ +#define SMALLCHESS_FACE_H_ + +#include "movement.h" + +/* + * Chess watchface + * + * Implements a (very) simple chess engine. + * Uses smallchesslib for the engine: https://codeberg.org/drummyfish/smallchesslib + * + * When moving a piece, only valid pieces and moves are presented. + * + * Interaction is done through a simple menu/submenu system: + * - Light button: navigate backwards through the current menu + * - Alarm button: navigate forwards through the current menu + * - Light button (long press): navigate up to the parent menu + * - Alarm button (long press): select the current item or submenu + */ + +enum smallchess_state { + /* main menu */ + SMALLCHESS_MENU_RESUME, + SMALLCHESS_MENU_SHOW_LAST_MOVE, + SMALLCHESS_MENU_UNDO, + SMALLCHESS_MENU_NEW_WHITE, + SMALLCHESS_MENU_NEW_BLACK, + + SMALLCHESS_PLAYING_SPLIT, + + /* playing game submenu */ + SMALLCHESS_SHOW_LAST_MOVE, + SMALLCHESS_SHOW_CPU_MOVE, + SMALLCHESS_SELECT_PIECE, + SMALLCHESS_SELECT_DEST, +}; + +#define NUM_ELEMENTS(a) (sizeof(a) / sizeof(a[0])) +#define SMALLCHESS_NUM_PIECES 16 // number of pieces each player has + +typedef struct { + void *game; + enum smallchess_state state; + uint8_t moveable_pieces[SMALLCHESS_NUM_PIECES + 1]; + uint8_t moveable_pieces_idx; + uint8_t moveable_dests[29]; // this magic number represents the maximum number of moves a piece can make (queen in center of board) + // plus one for the end list marker + uint8_t moveable_dests_idx; + char last_move_str[7]; + uint8_t ai_from_square, ai_to_square; +} smallchess_face_state_t; + +void smallchess_face_setup(movement_settings_t *settings, uint8_t watch_face_index, void ** context_ptr); +void smallchess_face_activate(movement_settings_t *settings, void *context); +bool smallchess_face_loop(movement_event_t event, movement_settings_t *settings, void *context); +void smallchess_face_resign(movement_settings_t *settings, void *context); + +#define smallchess_face ((const watch_face_t){ \ + smallchess_face_setup, \ + smallchess_face_activate, \ + smallchess_face_loop, \ + smallchess_face_resign, \ + NULL, \ +}) + +#endif // SMALLCHESS_FACE_H_