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#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "vector.h"
#include "chesshelpers.h"
board_t init_board(int** pieces) {
board_t board;
board.pieces = pieces;
board.whiteCanCastleKingside = 1;
board.whiteCanCastleQueenside = 1;
board.blackCanCastleKingside = 1;
board.blackCanCastleQueenside = 1;
board.lastPawnMove = -1;
return board;
}
//function applies side effects to board values like king move state
board_t make_move(board_t board, vector_t origin, vector_t end) {
int piece = board.pieces[origin.mx][origin.my];
int captured = board.pieces[end.mx][end.my];
board.pieces[origin.mx][origin.my] = 0;
board.pieces[end.mx][end.my] = piece;
//white king moved
if(piece == king) {
board.whiteCanCastleQueenside = 0;
board.whiteCanCastleKingside = 0;
//if the king moved farther than it normally could, move must have been castling. move the rook as well
if(origin.mx == 4 && end.mx == 6) {
board = make_move(board, init_vector(7, 7), init_vector(5, 7));
}
else if(origin.mx == 4 && end.mx == 2) {
board = make_move(board, init_vector(0, 7), init_vector(3, 7));
}
}
//white kingside rook moved
else if(origin.mx == 7 && origin.my == 7) {
board.whiteCanCastleKingside = 0;
}
//white queenside rook moved
else if(origin.mx == 0 && origin.my == 7) {
board.whiteCanCastleQueenside = 0;
}
//black king moved
else if(piece == king + 6) {
board.blackCanCastleQueenside = 0;
board.blackCanCastleKingside = 0;
//if the king moved farther than it normally could, move must have been castling. move the rook as well
if(origin.mx == 4 && end.mx == 6) {
board = make_move(board, init_vector(7, 0), init_vector(5, 0));
}
else if(origin.mx == 4 && end.mx == 2) {
board = make_move(board, init_vector(0, 0), init_vector(3, 0));
}
}
//black kingside rook moved
else if(origin.mx == 7 && origin.my == 0) {
board.blackCanCastleKingside = 0;
}
//black queenside rook moved
else if(origin.mx == 0 && origin.my == 0) {
board.blackCanCastleQueenside = 0;
}
//this is not an else if! lastPawnMove must be reset
if(piece == pawn || piece == pawn + 6) {
board.lastPawnMove = origin.mx;
//check if move was an en passant capture
if(captured == 0 && origin.mx != end.mx) {
//kill the enemy pawn
board.pieces[end.mx][origin.my] = 0;
}
}
else {
//en passant no longer possible
board.lastPawnMove = -1;
}
return board;
}
board_t clone_board(board_t board) {
board_t newBoard = board;
int** pieces = malloc(8 * sizeof(int*));
for(int r = 0; r < 8; r++) {
pieces[r] = malloc(8 * sizeof(int));
for(int c = 0; c < 8; c++) {
pieces[r][c] = board.pieces[r][c];
}
}
newBoard.pieces = pieces;
return newBoard;
}
int in_board(vector_t position) {
return position.mx < 8 && position.mx >= 0 && position.my < 8 && position.my >= 0;
}
int is_empty(board_t board, vector_t position) {
return board.pieces[position.mx][position.my] == 0;
}
int is_color(board_t board, vector_t position, int color) {
if(color == 0) {
return board.pieces[position.mx][position.my] >= 1 && board.pieces[position.mx][position.my] <= 6;
}
else {
return board.pieces[position.mx][position.my] >= 7;
}
}
//returns true if a pawn that moved two squares would have been here if it moved one square
int would_have_been_pawn(board_t board, vector_t position, int color) {
if(board.lastPawnMove == position.mx) {
if((position.my == 6 && color == 0) || (position.my == 2 && color == 1)) {
return 1;
}
}
return 0;
}
//converts board coordinates into algebraic notation
char* get_readable_coords(vector_t position) {
char* output = malloc(3 * sizeof(char));
output[0] = 'a' + position.mx;
output[1] = '8' - position.my;
output[2] = '\0';
return output;
}
//gets the proper algebraic notation for the move
char* get_move_name(board_t board, vector_t origin, vector_t end) {
int piece = board.pieces[origin.mx][origin.my];
if(piece > 6) {
piece -= 6;
}
if(piece != 1) {
char cPiece = piece == pawn ? 'P' : piece == knight ? 'N' : piece == bishop ? 'B' : piece == rook ? 'R' : piece == queen ? 'Q' : 'K';
int isCapture = board.pieces[end.mx][end.my] != 0;
char* output = calloc(isCapture ? 5 : 4, sizeof(char));
output[0] = cPiece;
if(isCapture) {
output[1] = 'x';
}
char* rEnd = get_readable_coords(end);
strcat(output, rEnd);
free(rEnd);
output[isCapture ? 4 : 3] = '\0';
return output;
}
else {
int isCapture = board.pieces[end.mx][end.my] != 0;
char* output = calloc(isCapture ? 5 : 3, sizeof(char));
if(isCapture) {
output[0] = 'a' + origin.mx;
output[1] = 'x';
}
char* rEnd = get_readable_coords(end);
strcat(output, rEnd);
free(rEnd);
output[isCapture ? 4 : 2] = '\0';
return output;
}
}
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