chess-puzzles

commit 6af435b4416d90cb27e447e2f0bf505721374e12
parent b7a52ecde26555a060898faaa5643851368c7467
Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date:   Mon, 25 Dec 2023 18:49:58 +0100

add util functions for (x,y) to (file, rank) and vice versa

Diffstat:
M
fen.c
 | 
46
+++++++++++++++++++++++++++++++++++-----------

1 file changed, 35 insertions(+), 11 deletions(-)
diff --git a/fen.c b/fen.c
@@ -97,12 +97,36 @@ getpiece(int x, int y)
 }
 
 int
+xtofile(int c)
+{
+	return 'a' + c;
+}
+
+int
+ytorank(int c)
+{
+	return '8' - c;
+}
+
+int
+filetox(int c)
+{
+	return c - 'a';
+}
+
+int
+ranktoy(int c)
+{
+	return '8' - c;
+}
+
+int
 squaretoxy(const char *s, int *x, int *y)
 {
 	if (*s >= 'a' && *s <= 'h' &&
 	    *(s + 1) >= '1' && *(s + 1) <= '8') {
-		*x = *s - 'a';
-		*y = '8' - *(s + 1);
+		*x = filetox(*s);
+		*y = ranktoy(*(s + 1));
 		return 1;
 	}
 	return 0;
@@ -153,8 +177,8 @@ showboardfen(void)
 	putchar(' ');
 
 	if (enpassantsquare[0] != -1 && enpassantsquare[1] != -1) {
-		putchar('a' + enpassantsquare[0]);
-		putchar('8' - enpassantsquare[1]);
+		putchar(xtofile(enpassantsquare[0]));
+		putchar(ytorank(enpassantsquare[1]));
 	} else {
 		putchar('-');
 	}
@@ -277,7 +301,7 @@ output_svg(void)
 				color = highlight[y][x] ? lightsquarehi : lightsquare;
 
 			printf("<text x=\"%d\" y=\"%d\" fill=\"#%02x%02x%02x\" text-anchor=\"end\" style=\"font-family: sans-serif; font-size: 10px\">%c</text>\n",
-				(ix + 1) * 45 - 2, (iy * 45) + 10, color[0], color[1], color[2], '8' - y);
+				(ix + 1) * 45 - 2, (iy * 45) + 10, color[0], color[1], color[2], ytorank(y));
 		}
 		iy = 7;
 		y = flipboard ? 0 : 7;
@@ -298,7 +322,7 @@ output_svg(void)
 			}
 
 			printf("<text x=\"%d\" y=\"%d\" fill=\"#%02x%02x%02x\" text-anchor=\"start\" style=\"font-family: sans-serif; font-size: 10px\">%c</text>\n",
-				(ix * 45) + 2, (iy + 1) * 45 - 3, color[0], color[1], color[2], x + 'a');
+				(ix * 45) + 2, (iy + 1) * 45 - 3, color[0], color[1], color[2], xtofile(x));
 		}
 	}
 
@@ -384,7 +408,7 @@ output_tty(void)
 		SETBGCOLOR(color[0], color[1], color[2]);
 		if (showcoords) {
 			fputs("\x1b[97m", stdout); /* bright white */
-			putchar('8' - y);
+			putchar(ytorank(y));
 			putchar(' ');
 		} else {
 			fputs("  ", stdout);
@@ -455,7 +479,7 @@ output_ascii(void)
 		}
 		if (showcoords) {
 			putchar(' ');
-			putchar('8' - y);
+			putchar(ytorank(y));
 		}
 		putchar('\n');
 	}
@@ -857,15 +881,15 @@ parsemoves(const char *moves)
 				if (piece != 'p' && piece != 'P') {
 					pgn("%c", toupper(piece));
 					/* TODO: check ambiguity for certain pieces and make the notation shorter */
-					pgn("%c%c", 'a' + x, '8' - y);
+					pgn("%c%c", xtofile(x), ytorank(y));
 				}
 				if (tookpiece) {
 					/* pawn captures are prefixed by the file letter */
 					if (piece == 'p' || piece == 'P')
-						pgn("%c", 'a' + x);
+						pgn("%c", xtofile(x));
 					pgn("x");
 				}
-				pgn("%c%c", 'a' + x2, '8' - y2);
+				pgn("%c%c", xtofile(x2), ytorank(y2));
 
 				/* possible promotion: queen, knight, bishop */
 				if (*s == 'q' || *s == 'n' || *s == 'b') {