1.1 --- a/src/rules/bishop.c Fri Mar 28 14:32:52 2014 +0100
1.2 +++ b/src/rules/bishop.c Sat Mar 29 14:46:33 2014 +0100
1.3 @@ -29,18 +29,100 @@
1.4
1.5 #include "bishop.h"
1.6 #include "rules.h"
1.7 +#include <math.h>
1.8
1.9 _Bool bishop_chkrules(Move* move) {
1.10 - // TODO: implement
1.11 + return abs(move->torow-move->fromrow) == abs(move->tofile-move->fromfile);
1.12 +}
1.13 +
1.14 +_Bool bishop_isblocked(Board board, Move *move) {
1.15 + int dy = move->torow > move->fromrow ? 1 : -1;
1.16 + int dx = move->tofile > move->fromfile ? 1 : -1;
1.17 +
1.18 + uint8_t y = move->fromrow;
1.19 + uint8_t x = move->fromfile;
1.20 +
1.21 + do {
1.22 + x += dx;
1.23 + y += dy;
1.24 + if (board[y][x]) {
1.25 + return TRUE;
1.26 + }
1.27 + } while (x != move->tofile && y != move->torow);
1.28 +
1.29 return FALSE;
1.30 }
1.31
1.32 -_Bool bishop_isblocked(Board board, Move *move) {
1.33 - // TODO: implement
1.34 - return TRUE;
1.35 +static int bishop_getloc_fixedfile(Board board, Move *move) {
1.36 + uint8_t d = abs(move->fromfile - move->tofile);
1.37 + if (board[move->torow - d][move->fromfile] == move->piece) {
1.38 + move->fromrow = move->torow - d;
1.39 + }
1.40 + if (board[move->torow + d][move->fromfile] == move->piece) {
1.41 + if (move->fromrow == POS_UNSPECIFIED) {
1.42 + move->fromrow = move->torow + d;
1.43 + } else {
1.44 + return AMBIGUOUS_MOVE; /* rare situation after promotion */
1.45 + }
1.46 + }
1.47 + return move->fromrow == POS_UNSPECIFIED ?
1.48 + INVALID_POSITION : VALID_MOVE_SYNTAX;
1.49 +}
1.50 +
1.51 +static int bishop_getloc_fixedrow(Board board, Move *move) {
1.52 + uint8_t d = abs(move->fromrow - move->torow);
1.53 + if (board[move->fromrow][move->tofile - d] == move->piece) {
1.54 + move->fromfile = move->tofile - d;
1.55 + }
1.56 + if (board[move->fromrow][move->tofile + d] == move->piece) {
1.57 + if (move->fromfile == POS_UNSPECIFIED) {
1.58 + move->fromfile = move->tofile + d;
1.59 + } else {
1.60 + return AMBIGUOUS_MOVE; /* rare situation after promotion */
1.61 + }
1.62 + }
1.63 + return move->fromfile == POS_UNSPECIFIED ?
1.64 + INVALID_POSITION : VALID_MOVE_SYNTAX;
1.65 }
1.66
1.67 int bishop_getlocation(Board board, Move *move) {
1.68 - // TODO: implement
1.69 - return INVALID_MOVE_SYNTAX;
1.70 +
1.71 + if (move->fromfile != POS_UNSPECIFIED) {
1.72 + return bishop_getloc_fixedfile(board, move);
1.73 + }
1.74 +
1.75 + if (move->fromrow != POS_UNSPECIFIED) {
1.76 + return bishop_getloc_fixedrow(board, move);
1.77 + }
1.78 +
1.79 + _Bool amb = FALSE;
1.80 + for (int d = -7 ; d < 8 ; d++) {
1.81 + uint8_t row = move->torow + d;
1.82 + if (isidx(row)) {
1.83 + uint8_t file = move->tofile + d;
1.84 + if (isidx(file) && board[row][file] == move->piece) {
1.85 + if (amb) {
1.86 + return AMBIGUOUS_MOVE;
1.87 + }
1.88 + amb = TRUE;
1.89 + move->fromrow = row;
1.90 + move->fromfile = file;
1.91 + }
1.92 + file = move->tofile - d;
1.93 + if (isfile(file) && board[row][file] == move->piece) {
1.94 + if (amb) {
1.95 + return AMBIGUOUS_MOVE;
1.96 + }
1.97 + amb = TRUE;
1.98 + move->fromrow = row;
1.99 + move->fromfile = file;
1.100 + }
1.101 + }
1.102 + }
1.103 +
1.104 + if (move->fromrow == POS_UNSPECIFIED || move->fromfile == POS_UNSPECIFIED) {
1.105 + return INVALID_POSITION;
1.106 + } else {
1.107 + return VALID_MOVE_SYNTAX;
1.108 + }
1.109 }
