static
void
MoveAndReplaceTarget(USER_DATA *ud, BOARD b, int x, int y, int dx, int dy)
{
PIECE *p = GetPieceAt(b, x, y);
PIECE old_p = *p;
// clear drawing at old location
LvzActivate(ud, NULL, p->color, p->type, x, y, false);
// unset target piece
PIECE *t = GetPieceAt(b, dx, dy);
if (t->type != TYPE_NONE) {
LvzActivate(ud, NULL, t->color, t->type, dx, dy, false);
}
// clear old location
SetPieceAt(b, x, y, COLOR_NONE, TYPE_NONE);
// copy old piece to new location
*t = old_p;
// draw it
LvzActivate(ud, NULL, t->color, t->type, dx, dy, true);
}
/*
* 'c' is the attackers color.
* kingx and kingy is the target king location.
*/
static
bool
IsCheckmatedBy(BOARD b, COLOR c, int kingx, int kingy)
{
struct timeval tv;
gettimeofday(&tv, NULL);
COLOR defender = GetOppositeColor(c);
PIECE *p;
// for each piece on the board that is defending
for (int x = 0; x < 8; ++x)
for (int y = 0; y < 8; ++y) {
p = GetPieceAt(b, x, y);
if (p->color != defender) {
continue;
}
// for each tile on the board, see if that piece can move there
for (int j = 0; j < 8; ++j)
for (int i = 0; i < 8; ++i) {
if (PieceCanAttack(b, p->color, p->type, x, y, i, j) == true &&
GetPieceAt(b, i, j)->color != p->color) {
PIECE old_p = *GetPieceAt(b, x, y);
PIECE old_t = *GetPieceAt(b, i, j);
// temporarily make the move
SetPieceAt(b, x, y, COLOR_NONE, TYPE_NONE);
SetPieceAt(b, i, j, old_p.color, old_p.type);
// see if the move cancels check
bool is_mate = true;
int kx, ky;
FindKing(b, defender, &kx, &ky);
if (IsCoordAttackedBy(b, c, kx, ky) == false) {
is_mate = false;
}
// revert the pieces
SetPieceAt(b, x, y, old_p.color, old_p.type);
SetPieceAt(b, i, j, old_t.color, old_t.type);
if (is_mate == false) {
struct timeval tv2;
gettimeofday(&tv2, NULL);
LogFmt(OP_MOD, "Checkmate Calculation: %lu.%06lu", tv2.tv_sec - tv.tv_sec, tv2.tv_usec - tv.tv_usec);
return false;
}
}
}
}
struct timeval tv2;
gettimeofday(&tv2, NULL);
LogFmt(OP_MOD, "Checkmate Calculation: %lu.%06lu", tv2.tv_sec - tv.tv_sec, tv2.tv_usec - tv.tv_usec);
return true;
}
static
void
LvzDrawAll(USER_DATA *ud, PLAYER *p, bool show)
{
PIECE *piece;
for (int j = 0; j < 8; ++j)
for (int i = 0; i < 8; ++i) {
piece = GetPieceAt(ud->board, i, j);
if (piece->type == TYPE_NONE) {
continue;
}
LvzActivate(ud, p, piece->color, piece->type, i, j, show);
}
}
static
bool
IsCoordAttackedBy(BOARD b, COLOR c, int x, int y)
{
PIECE *p;
for (int j = 0; j < 8; ++j) {
for (int i = 0; i < 8; ++i) {
p = GetPieceAt(b, i, j);
if (p->color == c &&
PieceCanAttack(b, c, p->type, i, j, x, y) == true) {
return true;
}
}
}
return false;
}
/*
* This function is no longer necessary with LVZ graphics but
* may still be useful for debugging at some point.
*/
static
void
DrawBoard(BOARD b)
{
text display
char line[128];
int linei = 0;
ArenaMessage("+---------------------+");
ArenaMessage("| a b c d e f g h |");
PIECE *p;
for (int y = 7; y >= 0; --y) {
line[linei++] = '|';
line[linei++] = ' ';
line[linei++] = '1' + y;
line[linei++] = '|';
for (int x = 0; x < 8; ++x) {
p = GetPieceAt(b, x, y);
char c;
if (p->type == TYPE_NONE) {
c = ' ';
} else {
if (p->color == COLOR_WHITE) {
c = p->type;
} else {
c = p->type + ('a' - 'A');
}
}
line[linei++] = c;
line[linei++] = '|';
}
line[linei++] = '1' + y;
line[linei++] = ' ';
line[linei++] = '|';
line[linei] = '\0';
linei = 0;
ArenaMessage("| +-+-+-+-+-+-+-+-+ |");
ArenaMessage(line);
}
ArenaMessage("| +-+-+-+-+-+-+-+-+ |");
ArenaMessage("| a b c d e f g h |");
ArenaMessage("|_____________________|");
}
static
void
FindKing(BOARD b, COLOR c, int *x, int *y)
{
*x = 0;
*y = 0;
PIECE *p;
for (int i = 0; i < 8; ++i) {
for (int j = 0; j < 8; ++j) {
p = GetPieceAt(b, j, i);
if (p->type == TYPE_KING && p->color == c) {
*x = j;
*y = i;
}
}
}
}
void Board::Print() const {
bool colour_toggle = false;
char rank = 8;
for (; rank >= 1; rank--) {
std::cout << char('0' + rank) << " ";
char file = 'A';
for (; file <= 'H'; file++) {
Piece p = GetPieceAt(rank, file);
if (p.GetType() == Piece::None) {
std::cout << (colour_toggle ? '.' : ' ');
}
else {
std::cout << p.GetText();
}
colour_toggle = !colour_toggle;
std::cout << ' ';
}
std::cout << std::endl;
colour_toggle = !colour_toggle;
}
std::cout << " A B C D E F G H " << std::endl;
}
/*
* TODO: rewrite this to remove duplicated code
*/
static
char*
TryCastle(USER_DATA *ud, COLOR c, int x, int y, int dx, int dy)
{
BOARD b = ud->board;
// coordinates were already verified by IsCastleMove()
COLOR opp = GetOppositeColor(c);
if (IsCoordAttackedBy(b, opp, x, y) == true) {
return "Can't castle out of check";
}
if (c == COLOR_WHITE) {
if (dx == 6) {
if (IsCoordAttackedBy(b, opp, 5, 0) ||
IsCoordAttackedBy(b, opp, 6, 0)) {
return "Can't castle through or into check";
}
if (GetPieceAt(b, 5, 0)->type != TYPE_NONE ||
GetPieceAt(b, 6, 0)->type != TYPE_NONE) {
return "Can't castle through pieces";
}
if (GetPieceAt(b, 7, 0)->type != TYPE_ROOK ||
GetPieceAt(b, 7, 0)->color != COLOR_WHITE) {
return "No rook";
}
MoveAndReplaceTarget(ud, b, x, y, dx, dy);
MoveAndReplaceTarget(ud, b, 7, 0, 5, 0);
ArenaMessageFmt("%s (%s) Moves: Castle kingside",
GetPlayerName(ud, c), GetColorText(c));
return NULL;
} else if (dx == 2) {
// castle queenside
if (IsCoordAttackedBy(b, opp, 2, 0) ||
IsCoordAttackedBy(b, opp, 3, 0)) {
return "Can't castle through or into check";
}
if (GetPieceAt(b, 1, 0)->type != TYPE_NONE ||
GetPieceAt(b, 2, 0)->type != TYPE_NONE ||
GetPieceAt(b, 3, 0)->type != TYPE_NONE) {
return "Can't castle through pieces";
}
if (GetPieceAt(b, 0, 0)->type != TYPE_ROOK ||
GetPieceAt(b, 0, 0)->color != COLOR_WHITE) {
return "No rook";
}
MoveAndReplaceTarget(ud, b, x, y, dx, dy);
MoveAndReplaceTarget(ud, b, 0, 0, 3, 0);
ArenaMessageFmt("%s (%s) Moves: Castle queenside",
GetPlayerName(ud, c), GetColorText(c));
return NULL;
}
} else if (c == COLOR_BLACK) {
if (dx == 6) {
// castle kingside
if (IsCoordAttackedBy(b, opp, 5, 7) ||
IsCoordAttackedBy(b, opp, 6, 7)) {
return "Can't castle through or into check";
}
if (GetPieceAt(b, 5, 7)->type != TYPE_NONE ||
GetPieceAt(b, 6, 7)->type != TYPE_NONE) {
return "Can't castle through pieces";
}
if (GetPieceAt(b, 7, 7)->type != TYPE_ROOK ||
GetPieceAt(b, 7, 7)->color != COLOR_BLACK) {
return "No rook";
}
MoveAndReplaceTarget(ud, b, x, y, dx, dy);
MoveAndReplaceTarget(ud, b, 7, 7, 5, 7);
ArenaMessageFmt("%s (%s) Moves: Castle kingside",
GetPlayerName(ud, c), GetColorText(c));
return NULL;
} else if (dx == 2) {
// castle queenside
if (IsCoordAttackedBy(b, opp, 2, 7) ||
IsCoordAttackedBy(b, opp, 3, 7)) {
return "Can't castle through or into check";
}
if (GetPieceAt(b, 1, 7)->type != TYPE_NONE ||
GetPieceAt(b, 2, 7)->type != TYPE_NONE ||
GetPieceAt(b, 3, 7)->type != TYPE_NONE) {
return "Can't castle through pieces";
}
if (GetPieceAt(b, 0, 7)->type != TYPE_ROOK ||
GetPieceAt(b, 0, 7)->color != COLOR_BLACK) {
return "No rook";
}
MoveAndReplaceTarget(ud, b, x, y, dx, dy);
MoveAndReplaceTarget(ud, b, 0, 7, 3, 7);
ArenaMessageFmt("%s (%s) Moves: Castle queenside",
GetPlayerName(ud, c), GetColorText(c));
return NULL;
}
} else {
return "Error castling";
}
return "Could not castle";
}
static
bool
PieceCanAttack(BOARD b, COLOR c, TYPE t, int x, int y, int dx, int dy)
{
if (dx < 0 || dx >= 8) {
return false;
} else if (dy < 0 || dy >= 8) {
return false;
} else if (x == dx && y == dy) {
// cant attack self
return false;
}
int tx, ty; // temp x and y values
PIECE *p;
switch (t) {
case TYPE_KING:
for (int j = x - 1; j <= x + 1; ++j)
for (int i = y - 1; i <= y + 1; ++i) {
if (j == dx && i == dy) {
return true;
}
}
break;
case TYPE_QUEEN:
return PieceCanAttack(b, c, TYPE_BISHOP, x, y, dx, dy) ||
PieceCanAttack(b, c, TYPE_ROOK, x, y, dx, dy);
case TYPE_ROOK:
// search up
for (int i = x + 1; i < 8; ++i) {
if (i == dx && y == dy) {
return true;
}
p = GetPieceAt(b, i, y);
if (p->type != TYPE_NONE) {
break;
}
}
// search down
for (int i = x - 1; i >= 0; --i) {
if (i == dx && y == dy) {
return true;
}
p = GetPieceAt(b, i, y);
if (p->type != TYPE_NONE) {
break;
}
}
// search right
for (int i = y + 1; i < 8; ++i) {
if (i == dy && x == dx) {
return true;
}
p = GetPieceAt(b, x, i);
if (p->type != TYPE_NONE) {
break;
}
}
// search left
for (int i = y - 1; i >= 0; --i) {
if (i == dy && x == dx) {
return true;
}
p = GetPieceAt(b, x, i);
if (p->type != TYPE_NONE) {
break;
}
}
break;
case TYPE_BISHOP:
// search up-right
for (int i = 1; x + i < 8 && y + i < 8; ++i) {
if (x + i == dx && y + i == dy) {
return true;
}
p = GetPieceAt(b, x + i, y + i);
if (p->type != TYPE_NONE) {
break;
}
}
// search down-right
for (int i = 1; x + i < 8 && y - i >= 0; ++i) {
if (x + i == dx && y - i == dy) {
return true;
}
p = GetPieceAt(b, x + i, y - i);
if (p->type != TYPE_NONE) {
break;
}
}
// search up-left
for (int i = 1; x - i >= 0 && y + i < 8; ++i) {
if (x - i == dx && y + i == dy) {
return true;
}
p = GetPieceAt(b, x - i, y + i);
if (p->type != TYPE_NONE) {
break;
}
}
// search down-left
for (int i = 1; x - i >= 0 && y - i >= 0; ++i) {
if (x - i == dx && y - i == dy) {
return true;
}
p = GetPieceAt(b, x - i, y - i);
if (p->type != TYPE_NONE) {
break;
}
}
break;
case TYPE_KNIGHT:
tx = abs(dx - x);
ty = abs(dy - y);
if ((tx == 2 && ty == 1) ||
(tx == 1 && ty == 2)) {
return true;
}
break;
case TYPE_PAWN:
// pawn special-case gheyness
if (c == COLOR_WHITE) {
if (y == 7) {
return false;
}
if (x == dx) {
// moving forward
if (GetPieceAt(b, x, y + 1)->type == TYPE_NONE
&& y + 1 == dy) {
return true;
}
// initial 2 square move option
if (y == 1 &&
GetPieceAt(b, x, y + 1)->type == TYPE_NONE &&
GetPieceAt(b, x, y + 2)->type == TYPE_NONE &&
y + 2 == dy) {
return true;
}
}
if (x > 0) {
// check attack left
if (GetPieceAt(b, x - 1, y + 1)->color == COLOR_BLACK &&
GetPieceAt(b, x - 1, y + 1)->type != TYPE_NONE) {
if (dx == x - 1 && dy == y + 1) {
return true;
}
}
}
if (x < 7) {
// check attack right
if (GetPieceAt(b, x + 1, y + 1)->color == COLOR_BLACK &&
GetPieceAt(b, x + 1, y + 1)->type != TYPE_NONE) {
if (dx == x + 1 && dy == y + 1) {
return true;
}
}
}
} else if (c == COLOR_BLACK) {
if (y == 0) {
return false;
}
if (x == dx) {
// moving forward
if (GetPieceAt(b, x, y - 1)->type == TYPE_NONE
&& y - 1 == dy) {
return true;
}
// initial 2 square move option
if (y == 6 &&
GetPieceAt(b, x, y - 1)->type == TYPE_NONE &&
GetPieceAt(b, x, y - 2)->type == TYPE_NONE &&
y - 2 == dy) {
return true;
}
}
if (x > 0) {
// check attack left
if (GetPieceAt(b, x - 1, y - 1)->color == COLOR_WHITE &&
GetPieceAt(b, x - 1, y - 1)->type != TYPE_NONE) {
if (dx == x - 1 && dy == y - 1) {
return true;
}
}
}
if (x < 7) {
// check attack right
if (GetPieceAt(b, x + 1, y - 1)->color == COLOR_WHITE &&
GetPieceAt(b, x + 1, y - 1)->type != TYPE_NONE) {
if (dx == x + 1 && dy == y - 1) {
return true;
}
}
}
}
break;
}
return false;
}
// TODO: Handle en passant
static
char*
TryMove(USER_DATA *ud, COLOR c, int x, int y, int dx, int dy)
{
BOARD b = ud->board;
PIECE *p = GetPieceAt(ud->board, x, y);
if (p->type == TYPE_NONE) {
return "No piece at that position!";
} else if (p->color != c) {
return "That piece is not yours!";
}
// check if this move is a castle attempt
// TODO: check for rook movements
if (p->type == TYPE_KING && IsCastleMove(c, x, y, dx, dy)) {
if (ColorCanCastle(ud, c) == false) {
return "You can no longer castle";
}
return TryCastle(ud, c, x, y, dx, dy);
}
// check that the piece can make this movement
if (PieceCanAttack(ud->board, c, p->type, x, y, dx, dy) == false) {
return "Piece can't make that movement";
}
// target piece
PIECE *t = GetPieceAt(ud->board, dx, dy);
if (t->type != TYPE_NONE && t->color == c) {
return "You already have a piece in the destination position!";
}
// make the movements to check for check, but store the data
// in case the board needs to be reverted
PIECE old_p = *p;
PIECE old_t = *t;
SetPieceAt(b, dx, dy, p->color, p->type);
SetPieceAt(b, x, y, COLOR_NONE, TYPE_NONE);
// find the king and test for check
int kingx, kingy;
FindKing(b, c, &kingx, &kingy);
if (IsCoordAttackedBy(b, GetOppositeColor(c), kingx, kingy) == true) {
// restore saved positions
SetPieceAt(b, x, y, old_p.color, old_p.type);
SetPieceAt(b, dx, dy, old_t.color, old_t.type);
return "That move would place your King in check!";
}
//
// At this point, the move was successful
//
// make the pieces blink
// TODO: this will erroneously leave pieces on if 2 moves
// are made quickly
uint32_t objid = LvzGetObjId(old_p.color, old_p.type, dx, dy);
SetTimer(500, (void*)objid, (void*)0);
SetTimer(1000, (void*)objid, (void*)1);
SetTimer(1500, (void*)objid, (void*)0);
SetTimer(2000, (void*)objid, (void*)1);
SetTimer(2500, (void*)objid, (void*)0);
SetTimer(3000, (void*)objid, (void*)1);
if (old_t.type != TYPE_NONE) {
// flash the captured piece
objid = LvzGetObjId(old_t.color, old_t.type, dx, dy);
SetTimer(500, (void*)objid, (void*)1);
SetTimer(1000, (void*)objid, (void*)0);
SetTimer(1500, (void*)objid, (void*)1);
SetTimer(2000, (void*)objid, (void*)0);
SetTimer(2500, (void*)objid, (void*)1);
SetTimer(3000, (void*)objid, (void*)0);
}
if (old_p.type == TYPE_KING) {
// kings cant castle once theyve moved
if (old_p.color == COLOR_WHITE) {
ud->white_can_castle = false;
} else if (old_p.color == COLOR_BLACK) {
ud->black_can_castle = false;
}
}
// set if a piece has been captured
bool capture = old_t.type != TYPE_NONE;
// remove drawing of the old pieces
LvzActivate(ud, NULL, old_p.color, old_p.type, x, y, false);
if (capture) {
LvzActivate(ud, NULL, old_t.color, old_t.type, dx, dy, false);
}
// check for pawn promotions
// TODO: handle underpromotions
bool promoted = false;
p = GetPieceAt(b, dx, dy);
if (p->type == TYPE_PAWN) {
if (p->color == COLOR_WHITE && dy == 7) {
p->type = TYPE_QUEEN;
promoted = true;
} else if (p->color == COLOR_BLACK && dy == 0) {
p->type = TYPE_QUEEN;
promoted = true;
}
}
// draw the new piece
LvzActivate(ud, NULL, old_p.color, old_p.type, dx, dy, true);
objid = LvzGetObjId(old_p.color, old_p.type, dx, dy);
// create move notation
char move[6];
move[0] = x + 'a';
move[1] = y + '1';
move[2] = ',';
move[3] = dx + 'a';
move[4] = dy + '1';
move[5] = '\0';
// announce the move
char line[256];
snprintf(line, 256, "%s (%s) Moves: %s",
GetPlayerName(ud, c), GetColorText(ud->to_move), move);
if (capture) {
// add capture line
char capture[64];
snprintf(capture, 64, ", capturing a %s!", GetTypeName(old_t.type));
strlcat(line, capture, 256);
}
if (promoted == true) {
// add promition line
strlcat(line, " Pawn promoted to Queen!", 256);
}
FindKing(b, GetOppositeColor(c), &kingx, &kingy);
if (IsCoordAttackedBy(b, c, kingx, kingy) == true) {
if (IsCheckmatedBy(b, c, kingx, kingy) == true) {
strlcat(line, " Checkmate!", 256);
ArenaMessage(line);
char gametime[32];
TicksToText(gametime, 32, GetTicksMs() - ud->start_tick);
StopGame(ud, "%s Wins in %s!", GetPlayerName(ud, c), gametime);
} else {
strlcat(line, " Check!", 256);
ArenaMessage(line);
}
} else {
ArenaMessage(line);
}
return NULL;
}