initial files

2021-10-27 16:09:56 +02:00
commit 264459dc0f
13 changed files with 1468 additions and 0 deletions
--- a/src/fen.c
+++ b/src/fen.c
@@ -0,0 +1,151 @@
+/* Starting Position :
+ * rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
+ * After 1.e4 :
+ * rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1
+ * After 1... c5 :
+ * rnbqkbnr/pp1ppppp/8/2p5/4P3/8/PPPP1PPP/RNBQKBNR w KQkq c6 0 2
+ * After 2. Nf3:
+ * rnbqkbnr/pp1ppppp/8/2p5/4P3/5N2/PPPP1PPP/RNBQKB1R b KQkq - 1 2
+ *
+ * 1 : White uppercase
+ * 2 : next move (w or b)
+ * 3 : Castling capabilities: "-" if none, KQ/kq if white/black can castle
+ *     on K or Q side
+ * 4 : en-passant: if pawn just moved 2 squares, indicate target square (e.g.
+ *     for e2-e4 this field is e3)
+ * 5 : half moves since last capture or pawn advance (for 50 moves rule)
+ * 6 : full moves, starts at 1, increments after black move
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "chessdefs.h"
+#include "position.h"
+#include "board.h"
+#include "fen.h"
+
+// warning, we expect a valid fen input
+POS *fen2pos(POS *pos, char *fen)
+{
+    char *p = fen;
+    int rank, file, skip;
+    BOARD *board = pos->board;
+#   define SKIP_BLANK(p) for(;*(p) == ' '; (p)++)
+
+    //pos_init(pos);
+
+    // 1) get piece placement information
+    for (rank = 7, file = 0; *p && *p != ' '; ++p) {
+        char cp = toupper(*p);
+        switch (cp) {
+            case CHAR_PAWN:
+                board[SQ88(file, rank)]->piece = PAWN;
+                goto color;
+            case CHAR_KNIGHT:
+                board[SQ88(file, rank)]->piece = KNIGHT;
+                goto color;
+            case CHAR_BISHOP:
+                board[SQ88(file, rank)]->piece = BISHOP;
+                goto color;
+            case CHAR_ROOK:
+                board[SQ88(file, rank)]->piece = ROOK;
+                goto color;
+            case CHAR_QUEEN:
+                board[SQ88(file, rank)]->piece = QUEEN;
+                goto color;
+            case CHAR_KING:
+                board[SQ88(file, rank)]->piece = KING;
+                goto color;
+                //printf("f=%d r=%d *p=%c piece=%c\n", file, rank, *p, cp);
+            color:
+                SET_COLOR(board[SQ88(file, rank)]->piece, islower(*p));
+                //board[SQ88(file, rank)]->piece |= isupper(*p)? WHITE: BLACK;
+                file++;
+                break;
+            case '/':
+                rank--;
+                file = 0;
+                break;
+            default:
+                skip = cp - '0';
+                file += skip;
+                while (skip--) {
+                    board[SQ88(file, rank)]->piece = EMPTY;
+                }
+        }
+    }
+    for (rank = 7; rank >= 0; --rank) {
+        for (file = 0; file < 8; ++file) {
+            printf("%2x ", board[SQ88(file, rank)]->piece);
+        }
+        putchar('\n');
+    }
+
+
+    // 2) next move color
+    SKIP_BLANK(p);
+    pos->turn = *p == 'w' ? TURN_WHITE : TURN_BLACK;
+    p++;
+
+    // 3) castle status
+    SKIP_BLANK(p);
+    pos->castle = 0;
+    if (*p != '-') {
+        for (; *p && *p != ' '; ++p) {
+            switch (*p) {
+                case 'K':
+                    pos->castle |= CASTLE_WK;
+                    break;
+                case 'k':
+                    pos->castle |= CASTLE_BK;
+                    break;
+                case 'Q':
+                    pos->castle |= CASTLE_WQ;
+                    break;
+                case 'q':
+                    pos->castle |= CASTLE_BQ;
+                    break;
+            }
+        }
+    }
+
+    // 4) en passant
+    SKIP_BLANK(p);
+    //printf("pos=%d\n", (int)(p-fen));
+    pos->en_passant = 0;
+    if (*p != '-') {
+        //printf("passant=%c\n", *p);
+        SET_F(pos->en_passant, C2FILE(*p++));
+        SET_R(pos->en_passant, C2RANK(*p++));
+        //printf("passant=%c\n", *p);
+    } else {
+        p++;
+    }
+
+    // 5) half moves since last capture or pawn move and
+    // 6) current move number
+    SKIP_BLANK(p);
+    //printf("pos=%d\n", (int)(p-fen));
+    sscanf(p, "%hd %hd", &pos->clock_50, &pos->curmove);
+    return pos;
+}
+
+#ifdef FENBIN
+int main(int ac, char**av)
+{
+    POS *pos;
+
+    pos = pos_create();
+    if (ac == 1) {
+        pos_startpos(pos);
+    } else {
+        fen2pos(pos, av[1]);
+    }
+    pos_print(pos);
+}
+#endif