X-Git-Url: https://git.draconx.ca/gitweb/rrace.git/blobdiff_plain/ec2e7b448d7d0d404c0b3102c5b25ac9464d9fc5..31d8eda9987703c64fc63f4ddb4088cf3be5b7cc:/src/game.c

diff --git a/src/game.c b/src/game.c
index c478eef..4946f8d 100644
--- a/src/game.c
+++ b/src/game.c
@@ -168,16 +168,43 @@ void game_reset(struct board *board)
 			board->y = y;
 		}
 	}
+
+/* Uncomment to make every game stupidly easy -- winnable in 1 move */
+#if 0
+	/* Force empty space to the border */
+	if (board_position(board->x, board->y) & GOAL_MASK) {
+		switch (rng_uniform_int(4)) {
+		case 0: game_do_move(board, board->x, 0); break;
+		case 1: game_do_move(board, board->x, 4); break;
+		case 2: game_do_move(board, 0, board->y); break;
+		case 3: game_do_move(board, 4, board->y); break;
+		}
+	}
+
+	/* Force goal to match the current board */
+	for (i = 0; i < 3; i++) {
+		board->goal[i] = (board->game[i] & GOAL_MASK) >> GOAL_SHIFT;
+	}
+
+	/* Move empty space back to the centre */
+	if (board->x == 0 || board->x == 4) {
+		game_do_move(board, 1+rng_uniform_int(3), board->y);
+	}
+
+	if (board->y == 0 || board->y == 4) {
+		game_do_move(board, board->x, 1+rng_uniform_int(3));
+	}
+#endif
 }
 
-int game_do_move(struct board *board, int x, int y)
+uint_fast32_t game_do_move(struct board *board, int x, int y)
 {
 	int bx = board->x, by = board->y;
-	uint_least32_t mask, val[4];
+	uint_least32_t ret = 0, mask, val[4];
 	int i, shl, shr;
 
 	if ((bx != x) == (by != y))
-		return -1;
+		return 0;
 
 	if (bx == x) {
 		mask = board_mask_v(x, by, y);
@@ -192,20 +219,25 @@ int game_do_move(struct board *board, int x, int y)
 	for (i = 0; i < 4; i++) {
 		board->game[i] ^= (val[i] = board->game[i] & mask);
 		board->game[i] |= val[i] << shl >> shr;
+		ret |= board->game[i] ^ val[i];
 	}
 
 	board->x = x;
 	board->y = y;
-	return 0;
+
+	return mask & ret;
 }
 
-int game_check_goal(struct board *board)
+uint_fast32_t game_check_goal(struct board *board)
 {
-	int i, ret = 1;
+	uint_least32_t *game = board->game;
+	uint_least16_t *goal = board->goal;
+	uint_least32_t mask = 0;
+	int i;
 
 	for (i = 0; i < 3; i++)
-		ret &= ((board->game[i] & GOAL_MASK) >> 6) == board->goal[i];
-	return ret;
+		mask |= goal[i] ^ (game[i] >> GOAL_SHIFT);
+	return (mask << GOAL_SHIFT) & GOAL_MASK;
 }
 
 void game_begin(struct board *board)
@@ -213,14 +245,14 @@ void game_begin(struct board *board)
 	board->time_start = gethrxtime();
 }
 
-static int_fast32_t elapsed(struct board *board)
+int_fast32_t game_elapsed(struct board *board)
 {
 	return (gethrxtime() - board->time_start) / 1000000;
 }
 
 int_fast32_t game_finish(struct board *board)
 {
-	int_fast32_t t = elapsed(board);
+	int_fast32_t t = game_elapsed(board);
 	int i;
 
 	for (i = 0; i < 4; i++) {