Subversion Repositories Games.Chess Giants

// board.cpp

#include "common.h"

// initial position of a chess game :

//

//  +-----------------+

// 8| R K B Q K B K R | - black

// 7| P P P P P P P P |

// 6|                 |

// 5|                 |

// 4|                 |

// 3|                 |

// 2| P P P P P P P P |

// 1| R K B Q K B K R | - white

//  +-----------------+

//    a b c d e f g h

bool Board_Init (board_t *board, int white_playertype, int black_playertype, wchar_t *fen_string)

{

   // this function initializes a new chess game

   bool is_success;

   // initialize the moves array and blank out the first move's structure

   board->moves = (boardmove_t *) SAFE_malloc (1, sizeof (boardmove_t), false);

   memset (&board->moves[0], 0, sizeof (boardmove_t));

   board->viewed_move = 0;

   board->move_count = 1;

   board->game_state = STATE_UNKNOWN; // game has not started yet

   board->lastmove_time = 0.0f;

   // initialize this board's players

   Player_Init (&board->players[COLOR_WHITE], COLOR_WHITE, white_playertype);

   Player_Init (&board->players[COLOR_BLACK], COLOR_BLACK, black_playertype);

   // can we NOT successfully initialize from the given FEN string ?

   is_success = Move_SetupFromFEN (&board->moves[0], fen_string);

   if (!is_success)

      Move_SetupFromFEN (&board->moves[0], FENSTARTUP_STANDARDCHESS); // if so, fallback to standard chess table

   // reset all selection and hovering information

   Board_SetSelectedAndHovered (board, -1, -1, -1, -1);

   // notify that board was just set up

   board->was_setup = true;

   board->has_playerchanged = true;

   board->reevaluate = true;

   return (is_success); // finished

}

void Board_Shutdown (board_t *board)

{

   // this function ends a chess game

   boardmove_t *move;

   int move_index;

   // reset the moves array

   for (move_index = 0; move_index < board->move_count; move_index++)

   {

      move = &board->moves[move_index]; // quick access to move

      SAFE_free ((void **) &move->sides[COLOR_WHITE].takenparts); // free white's taken parts

      SAFE_free ((void **) &move->sides[COLOR_BLACK].takenparts); // free black's taken parts

      SAFE_free ((void **) &move->comment); // free each move comment

   }

   SAFE_free ((void **) &board->moves); // and the moves array itself

   board->viewed_move = -1;

   board->move_count = 0;

   // release players

   Player_Shutdown (&board->players[COLOR_WHITE]);

   Player_Shutdown (&board->players[COLOR_BLACK]);

   // game has not started yet

   board->game_state = STATE_UNKNOWN;

   return; // that's all there is

}

bool Board_Reset (board_t *board, wchar_t *fen_string)

{

   // this function initializes a chess game according to a FEN string, WITHOUT changing the players

   boardmove_t *move;

   int move_index;

   bool is_success;

   // reset the moves array

   for (move_index = 0; move_index < board->move_count; move_index++)

   {

      move = &board->moves[move_index]; // quick access to move

      SAFE_free ((void **) &move->sides[COLOR_WHITE].takenparts); // free white's taken parts

      SAFE_free ((void **) &move->sides[COLOR_BLACK].takenparts); // free black's taken parts

      SAFE_free ((void **) &move->comment); // free each move comment

   }

   // resize the moves array and blank out the first move's structure

   board->moves = (boardmove_t *) SAFE_realloc (board->moves, board->move_count, 1, sizeof (boardmove_t), false);

   memset (&board->moves[0], 0, sizeof (boardmove_t));

   board->viewed_move = 0;

   board->move_count = 1;

   board->game_state = STATE_UNKNOWN; // game has not started yet

   board->lastmove_time = 0.0f;

   // reset the players' view angles

   Player_ResetView (&board->players[COLOR_BLACK]);

   Player_ResetView (&board->players[COLOR_WHITE]);

   // can we NOT successfully initialize from the given FEN string ?

   is_success = Move_SetupFromFEN (&board->moves[0], fen_string);

   if (!is_success)

      Move_SetupFromFEN (&board->moves[0], FENSTARTUP_STANDARDCHESS); // if so, fallback to standard chess table

   // reset all selection and hovering information

   Board_SetSelectedAndHovered (board, -1, -1, -1, -1);

   // notify that board was just set up

   board->was_setup = true;

   board->has_playerchanged = true;

   return (is_success); // finished

}

bool Board_Think (board_t *board)

{

   // helper function to make both a board's players think

   bool do_update;

   do_update = false; // don't update scene until told otherwise

   do_update |= Player_Think (&board->players[COLOR_WHITE]); // make white player think

   do_update |= Player_Think (&board->players[COLOR_BLACK]); // make black player think

   // do the board sides need to be swapped ?

   if (board->want_playerswap)

   {

      Board_SwapSides (board); // if so, swap board sides

      board->want_playerswap = false; // don't do this all day long

      do_update |= true; // and update the scene

   }

   // clear board notifications (they should have been processed in Player_Think())

   board->was_setup = false;

   board->has_playerchanged = false;

   return (do_update); // finished, return whether we update the scene or not

}

void Board_SwapSides (board_t *board)

{

   // helper function to swap a board's sides

   player_t player_to_swap;

   // THREAD-SAFE: wait until all buffers are unlocked

   while (board->players[COLOR_BLACK].sendbuffer_locked

          || board->players[COLOR_WHITE].sendbuffer_locked)

      Sleep (10); // test again in 10 milliseconds

   // lock all the buffers at once

   board->players[COLOR_BLACK].sendbuffer_locked = true;

   board->players[COLOR_WHITE].sendbuffer_locked = true;

   // swap players structures

   memcpy (&player_to_swap, &board->players[COLOR_BLACK], sizeof (player_t));

   memcpy (&board->players[COLOR_BLACK], &board->players[COLOR_WHITE], sizeof (player_t));

   memcpy (&board->players[COLOR_WHITE], &player_to_swap, sizeof (player_t));

   // restore correct colors

   board->players[COLOR_BLACK].color = COLOR_BLACK;

   board->players[COLOR_WHITE].color = COLOR_WHITE;

   // turn their point of view 180 degrees

   board->players[COLOR_BLACK].view_yaw = WrapAngle (board->players[COLOR_BLACK].view_yaw + 180.0f);

   board->players[COLOR_WHITE].view_yaw = WrapAngle (board->players[COLOR_WHITE].view_yaw + 180.0f);

   // now unlock all the players' buffers

   board->players[COLOR_BLACK].sendbuffer_locked = false;

   board->players[COLOR_WHITE].sendbuffer_locked = false;

   board->reevaluate = true; // remember to reevaluate this board

   return; // finished

}

void Board_SetSelectedAndHovered (board_t *board, int selected_line, int selected_column, int hovered_line, int hovered_column)

{

   // helper function to forcibly set a board's selected and hovered slots (respectively move source and destination)

   board->selected_position[0] = selected_line;

   board->selected_position[1] = selected_column;

   board->hovered_position[0] = hovered_line;

   board->hovered_position[1] = hovered_column;

   return; // finished

}

char Board_ColorToMove (board_t *board)

{

   // helper function that returns the current color to move for the given board

   // NOTE: since the return value may be used to address an array, DO NOT return an invalid value !

   if ((board->moves == NULL) || (board->move_count < 1))

      return (COLOR_WHITE); // consistency check

   return (1 - board->moves[the_board.move_count - 1].color); // return the opposite color of the last move's color

}

void Board_AppendMove (board_t *board, int from_line, int from_column, int to_line, int to_column, char promotion_type, wchar_t *comment)

{

   // this function processes a part movement on the specified board.

   boardmove_t *last_move;

   boardmove_t new_move;

   int side_index;

   boardside_t *playing_side;

   boardside_t *opposing_side;

   // get a quick access to board's last move

   last_move = &board->moves[board->move_count - 1];

   // prepare the new move

   new_move.color = 1 - last_move->color; // switch colors

   new_move.part = last_move->slots[from_line][from_column].part; // save the move part type

   new_move.promotion_type = promotion_type; // save the promotion type

   new_move.has_captured = false; // assume there's no capture until told otherwise

   new_move.is_enpassant = false; // assume no en passant coup is played until told otherwise

   new_move.is_check = false; // assume no check until told otherwise

   new_move.is_stalemate = false; // assume no stalemate until told otherwise

   new_move.source[0] = from_line; // save the move source line and column

   new_move.source[1] = from_column;

   new_move.target[0] = to_line; // save the move target line and column

   new_move.target[1] = to_column;

   new_move.pgntext[0] = 0; // will be evaluated at the end of this function

   new_move.comment = NULL; // assume no comment until told otherwise

   new_move.comment_size = 0;

   for (side_index = 0; side_index < 2; side_index++)

   {

      new_move.sides[side_index].takenparts = (unsigned char *) SAFE_malloc (last_move->sides[side_index].takenpart_count, sizeof (unsigned char), false);

      memcpy (new_move.sides[side_index].takenparts, last_move->sides[side_index].takenparts, last_move->sides[side_index].takenpart_count * sizeof (unsigned char));

      new_move.sides[side_index].takenpart_count = last_move->sides[side_index].takenpart_count; // copy side's taken parts

      new_move.sides[side_index].shortcastle_allowed = last_move->sides[side_index].shortcastle_allowed; // copy whether side can castle short

      new_move.sides[side_index].longcastle_allowed = last_move->sides[side_index].longcastle_allowed; // copy whether side can castle long

   }

   memcpy (&new_move.slots, last_move->slots, sizeof (last_move->slots)); // copy table disposition

   new_move.fen_string[0] = 0; // will be evaluated at the end of this function

   // get a quick access to current and opposing sides

   playing_side = &new_move.sides[new_move.color];

   opposing_side = &new_move.sides[1 - new_move.color];

   // is a piece being taken ?

   if (new_move.slots[to_line][to_column].part != PART_NONE)

   {

      // was the piece being taken a rook ?

      if (new_move.slots[to_line][to_column].part == PART_ROOK)

      {

         // was it a white tower in A1, a white tower in A7, a black tower in H1 or a black tower in H7 ?

         if ((new_move.slots[to_line][to_column].color == COLOR_WHITE) && (to_line == 0) && (to_column == 0))

            new_move.sides[COLOR_WHITE].longcastle_allowed = false; // our opponent can no longer castle queenside

         else if ((new_move.slots[to_line][to_column].color == COLOR_WHITE) && (to_line == 0) && (to_column == 7))

            new_move.sides[COLOR_WHITE].shortcastle_allowed = false; // our opponent can no longer castle bishopside

         else if ((new_move.slots[to_line][to_column].color == COLOR_BLACK) && (to_line == 7) && (to_column == 0))

            new_move.sides[COLOR_BLACK].longcastle_allowed = false; // our opponent can no longer castle queenside

         else if ((new_move.slots[to_line][to_column].color == COLOR_BLACK) && (to_line == 7) && (to_column == 7))

            new_move.sides[COLOR_BLACK].shortcastle_allowed = false; // our opponent can no longer castle bishopside

      }

      // resize this players' taken parts array and move the taken piece in it

      playing_side->takenparts = (unsigned char *) SAFE_realloc (playing_side->takenparts, playing_side->takenpart_count, playing_side->takenpart_count + 1, sizeof (unsigned char), true);

      playing_side->takenparts[playing_side->takenpart_count] = new_move.slots[to_line][to_column].part;

      playing_side->takenpart_count++; // player has now taken one piece more

      new_move.has_captured = true; // remember a part has just been captured

   }

   // else is it an "en passant" coup ?

   else if ((new_move.slots[from_line][from_column].part == PART_PAWN) // we're a pawn

            && (abs (to_column - from_column) == 1) // we moved diagonally

            && (new_move.slots[to_line][to_column].part == PART_NONE) // no part on destination

            && (new_move.slots[from_line][to_column].part == PART_PAWN)) // but a pawn next to us

   {

      // resize this players' taken parts array and move the taken piece in it

      playing_side->takenparts = (unsigned char *) SAFE_realloc (playing_side->takenparts, playing_side->takenpart_count, playing_side->takenpart_count + 1, sizeof (unsigned char), true);

      playing_side->takenparts[playing_side->takenpart_count] = new_move.slots[from_line][to_column].part;

      memset (&new_move.slots[from_line][to_column], 0, sizeof (boardslot_t)); // "en passant" coup

      playing_side->takenpart_count++; // player has now taken one piece more

      new_move.has_captured = true; // remember a part has just been captured

      new_move.is_enpassant = true; // and that it's an en passant coup

   }

   // has a promotion been specified ?

   if (promotion_type != PART_NONE)

      Move_SetSlot (&new_move, from_line, from_column, new_move.color, promotion_type); // promote the pawn to the desired type

   // was the moved part the king ? if so, player can't castle anymore

   if (new_move.slots[from_line][from_column].part == PART_KING)

   {

      // did the king castle queenside ? or did it castle bishopside ?

      if ((from_column == 4) && (to_column == 2))

      {

         // move the rook from A to D (0 -> 3) and wipe its previous location

         memcpy (&new_move.slots[to_line][3], &new_move.slots[from_line][0], sizeof (boardslot_t));

         memset (&new_move.slots[from_line][0], 0, sizeof (boardslot_t));

      }

      else if ((from_column == 4) && (to_column == 6))

      {

         // move the rook from H to F (7 -> 5) and wipe its previous location

         memcpy (&new_move.slots[to_line][5], &new_move.slots[from_line][7], sizeof (boardslot_t));

         memset (&new_move.slots[from_line][7], 0, sizeof (boardslot_t));

      }

      // no matter whether it castled or not, remember this king cannot castle anymore

      playing_side->shortcastle_allowed = false;

      playing_side->longcastle_allowed = false;

   }

   // else was it the rook ?

   else if (new_move.slots[from_line][from_column].part == PART_ROOK)

   {

      // was the tower in A ? or was it in H ?

      if (from_column == 0)

         playing_side->longcastle_allowed = false; // player can no longer castle queenside

      else if (from_column == 7)

         playing_side->shortcastle_allowed = false; // player can no longer castle bishopside

   }

   // move the part and erase the starting slot

   memcpy (&new_move.slots[to_line][to_column], &new_move.slots[from_line][from_column], sizeof (boardslot_t));

   memset (&new_move.slots[from_line][from_column], 0, sizeof (boardslot_t));

   // does the new move have a comment ? if so, save it

   if ((comment != NULL) && (comment[0] != 0))

   {

      new_move.comment_size = wcslen (comment) + 1; // save this move's comment and the size of the mallocated space

      new_move.comment = (wchar_t *) SAFE_malloc (new_move.comment_size, sizeof (wchar_t), false);

      wcscpy_s (new_move.comment, new_move.comment_size, comment); // copy comment

   }

   // evaluate check and stalemate status

   new_move.is_check = Move_IsCheck (&new_move, 1 - new_move.color); // save whether opponent is in check or not

   new_move.is_stalemate = Move_IsStaleMate (&new_move, 1 - new_move.color); // save whether opponent is stalemate

   // describe our move in Standard Abbreviated Notation and describe the resulting table in Forsyth-Edwards Notation

   Move_DescribeInSAN (&new_move);

   Move_DescribeInFEN (&new_move);

   // resize the previous moves array and insert our new move at the end of it

   board->moves = (boardmove_t *) SAFE_realloc (board->moves, board->move_count, board->move_count + 1, sizeof (boardmove_t), false);

   memcpy (&board->moves[board->move_count], &new_move, sizeof (boardmove_t));

   board->move_count++; // we know now one previous move more

   board->viewed_move = board->move_count - 1; // set the move to be viewed to be the last move

   // if the game hadn't started yet, remember it has now

   if (board->game_state == STATE_UNKNOWN)

      board->game_state = STATE_PLAYING;

   // remember the last move time

   board->lastmove_time = current_time;

   // reset stoppage time

   stoppage_time = 0;

   // remember the game state should be reevaluated

   board->reevaluate = true;

   return; // finished

}