X-Git-Url: https://git.draconx.ca/gitweb/rrace.git/blobdiff_plain/26fb4b6902a32be6e9f504bee44724a0dd4292f7..86abb005c1109dfb7ac55f0d38474c5fdcb52b78:/src/game.h

diff --git a/src/game.h b/src/game.h
index 6a02a42..7640b41 100644
--- a/src/game.h
+++ b/src/game.h
@@ -20,6 +20,7 @@
 #define RRACE_GAME_H_
 
 #include <inttypes.h>
+#include <xtime.h>
 
 enum {
 	TILE_EMPTY,
@@ -65,8 +66,10 @@ struct board {
 	 */
 	uint_least16_t goal[3];
 
-	/* (x, y) position of the current empty position. */
+	/* (x, y) position of the current empty space. */
 	uint_least8_t x, y;
+
+	xtime_t time_start;
 };
 
 /* Return the board bitmap with all bits in column x set */
@@ -118,9 +121,7 @@ static inline uint_fast32_t board_mask_v(int x, int y0, int y1)
  */
 static inline uint_fast32_t board_above(int y)
 {
-	uint_fast32_t val = board_row(y);
-
-	return val | (val-1);
+	return ( 0x20ul << 5*y ) - 1;
 }
 
 /*
@@ -128,9 +129,7 @@ static inline uint_fast32_t board_above(int y)
  */
 static inline uint_fast32_t board_below(int y)
 {
-	uint_fast32_t val = board_row(y);
-
-	return val | (~val + 1);
+	return ~( 1ul << 5*y ) + 1;
 }
 
 /*
@@ -153,19 +152,36 @@ static inline uint_fast32_t board_right(int x)
 	return ~val + 0x108421;
 }
 
+/*
+ * Return the board bitmap setting the rectangle of locations that are:
+ *
+ *   - on or right of column x1, and
+ *   - on or left of column x2, and
+ *   - on or below row y1, and
+ *   - on or above row y2.
+ *
+ * It must be the case that x2 >= x1 and y2 >= y1.
+ */
+static inline uint_fast32_t board_rect(int x1, int y1, int x2, int y2)
+{
+	return (board_left(x2-x1) << x1) & (board_above(y2-y1) << 5*y1);
+}
+
 /*
  * Move the bits in the game bitmaps according to a move at position (x, y),
  * and update the location of the empty position which, if the move was valid
  * is now (x, y).
  *
- * Returns 0 if the move was valid (and board has been updated), -1 otherwise.
+ * Returns the board bitmap indicating which positions changed.  A return
+ * value of 0 therefore indicates an invalid move.
  */
-int game_do_move(struct board *board, int x, int y);
+uint_fast32_t game_do_move(struct board *board, int x, int y);
 
 /*
- * Returns 1 if the game is in a winning position, or 0 otherwise.
+ * Returns the board bitmap setting game locations that differ from the goal.
+ * A return value of 0 therefore indicates a winning position.
  */
-int game_check_goal(struct board *board);
+uint_fast32_t game_check_goal(struct board *board);
 
 /*
  * Initialize the game RNG such that the next call to game_reset will produce a
@@ -178,9 +194,20 @@ void game_reseed(unsigned long long seed);
  */
 void game_reset(struct board *board);
 
+/*
+ * Reset the game start time.
+ */
+void game_begin(struct board *board);
+
+/*
+ * Return the total elapsed time (in ms) since the last call to game_begin.
+ */
+int_fast32_t game_elapsed(struct board *board);
+
 /*
  * Disable new moves and clear all tile bits other than the 9 goal tiles.
+ * Returns the total elapsed time (in ms).
  */
-void game_finish(struct board *board);
+int_fast32_t game_finish(struct board *board);
 
 #endif