Simplify tile storage using bitfields

Instead of storing tiles as uint8_t, they are now stored as a
struct minesweeper_tile, which still should only be 8 bits wide,
but each property is addressable without bitmasking.

This is a breaking API change, since some functions that were
previously used to access data encoded in the tiles are no longer
needed. All data can be accessed in the tile directly.

include/minesweeper.h

@@ -5,12 +5,6 @@
 #include <stdbool.h>
 #include <stddef.h>
 
-enum {
-	TILE_OPENED = 1,
-	TILE_MINE = 1 << 1,
-	TILE_FLAG = 1 << 2
-};
-
 enum direction {
 	LEFT,
 	RIGHT,
@@ -25,8 +19,15 @@ enum minesweeper_game_state {
 	MINESWEEPER_GAME_OVER
 };
 
+struct minesweeper_tile {
+	uint8_t adjacent_mine_count : 4;
+	bool has_flag : 1;
+	bool has_mine : 1;
+	bool is_opened : 1;
+};
+
 struct minesweeper_game;
-typedef void (*minesweeper_callback) (struct minesweeper_game *game, uint8_t *tile, void *user_info);
+typedef void (*minesweeper_callback) (struct minesweeper_game *game, struct minesweeper_tile *tile, void *user_info);
 
 /**
  * Contains data for a single minesweeper game.
@@ -42,8 +43,8 @@ struct minesweeper_game {
 	unsigned mine_count;
 	unsigned opened_tile_count;
 	unsigned flag_count;
-	uint8_t *selected_tile; /* Pointer to the tile under the cursor */
-	uint8_t *data;          /* Tile buffer */
+	struct minesweeper_tile *selected_tile; /* Pointer to the tile under the cursor */
+	struct minesweeper_tile *tiles;
 	enum minesweeper_game_state state;
 	minesweeper_callback tile_update_callback; /* Optional function pointer to receive tile state updates */
 	void *user_info; /* Can be used for anything, will be passed as a parameter to tile_update_callback */
@@ -87,44 +88,38 @@ void minesweeper_move_cursor(struct minesweeper_game *game, enum direction direc
  * be opened instead, to imitate the quick-open functionality of most
  * minesweeper games.
  */
-void minesweeper_open_tile(struct minesweeper_game *game, uint8_t *tile);
+void minesweeper_open_tile(struct minesweeper_game *game, struct minesweeper_tile *tile);
 
 /**
  * Toggles a flag on an unopened tile.
  */
-void minesweeper_toggle_flag(struct minesweeper_game *game, uint8_t *tile);
+void minesweeper_toggle_flag(struct minesweeper_game *game, struct minesweeper_tile *tile);
 
 /**
  * Get pointer to tile at location. Returns NULL if location if out of bounds.
  */
-uint8_t *minesweeper_get_tile_at(struct minesweeper_game *game, unsigned x, unsigned y);
+struct minesweeper_tile *minesweeper_get_tile_at(struct minesweeper_game *game, unsigned x, unsigned y);
 
 /**
  * Get location of a tile.
  *
  * x/y: Pointers to integers which the result will be written to.
  */
-void minesweeper_get_tile_location(struct minesweeper_game *game, uint8_t *tile, unsigned *x, unsigned *y);
+void minesweeper_get_tile_location(struct minesweeper_game *game, struct minesweeper_tile *tile, unsigned *x, unsigned *y);
 
 /**
  * Get all tiles adjacent to tile. A tile can have at most 8 adjacent tiles,
  * but tiles adjacent to edges of the game area will have fewer.
  *
- * adjacent_tiles: A pointer to an array of 8 uint8_t pointers. The resulting tiles will
+ * adjacent_tiles: A pointer to an array of 8 tile pointers. Pointers to the resulting tiles will
  * be written to this array. Some tiles may be NULL, if tile is adjacent to an edge.
  */
-void minesweeper_get_adjacent_tiles(struct minesweeper_game *game, uint8_t *tile, uint8_t *adjacent_tiles[8]);
-
-/**
- * Returns the number of adjacent mines for a tile. This is
- * the colored number that is shown on tiles in most minesweepers.
- */
-uint8_t minesweeper_get_adjacent_mine_count(uint8_t *tile);
+void minesweeper_get_adjacent_tiles(struct minesweeper_game *game, struct minesweeper_tile *tile, struct minesweeper_tile *adjacent_tiles[8]);
 
 /**
  * Toggles a mine on a tile, and adjusts the adjacent mine counts for all
  * adjacent tiles.
  */
-void minesweeper_toggle_mine(struct minesweeper_game *game, uint8_t *tile);
+void minesweeper_toggle_mine(struct minesweeper_game *game, struct minesweeper_tile *tile);
 
 #endif

include/minesweeper.hpp

@@ -29,8 +29,8 @@ namespace Minesweeper {
 		}
 
 	private:
-		Tile(uint8_t *internal, minesweeper_game *game): internal(internal), game(game) {}
-		uint8_t *internal;
+		Tile(minesweeper_tile *internal, minesweeper_game *game): internal(internal), game(game) {}
+		minesweeper_tile *internal;
 		minesweeper_game *game;
 	};
 
@@ -55,7 +55,7 @@ namespace Minesweeper {
 		minesweeper_game *internal;
 	};
 
-	extern "C" void callbackHandler(minesweeper_game *game, uint8_t *tile, void *context) {
+	extern "C" void callbackHandler(minesweeper_game *game, struct minesweeper_tile *tile, void *context) {
 		Game *gameObject = (Game *)context;
 		unsigned x, y; minesweeper_get_tile_location(game, tile, &x, &y);
 		Tile tileObject = gameObject->tileAt(x, y);
@@ -106,14 +106,14 @@ namespace Minesweeper {
 	}
 
 	inline Tile Game::selectedTile() {
-		uint8_t *tilePtr = internal->selected_tile;
+		minesweeper_tile *tilePtr = internal->selected_tile;
 		if (tilePtr == NULL)
 			throw std::logic_error("No tile is selected. Call setCursor() first.");
 		return Tile(tilePtr, this->internal);
 	}
 
 	inline Tile Game::tileAt(unsigned x, unsigned y) {
-		uint8_t *tilePtr = minesweeper_get_tile_at(internal, x, y);
+		minesweeper_tile *tilePtr = minesweeper_get_tile_at(internal, x, y);
 		if (tilePtr == NULL)
 			throw std::out_of_range("Tile is out of bounds for this game.");
 		return Tile(tilePtr, this->internal);
@@ -128,32 +128,32 @@ namespace Minesweeper {
 	}
 
 	inline uint8_t Tile::adjacentMineCount() {
-		return minesweeper_get_adjacent_mine_count(internal);
+		return internal->adjacent_mine_count;
 	}
 
 	inline void Tile::toggleMine() {
 		minesweeper_toggle_mine(game, internal);
 	}
 
 	inline bool Tile::hasMine() {
-		return *internal & TILE_MINE;
+		return internal->has_mine;
 	}
 
 	inline bool Tile::hasFlag() {
-		return *internal & TILE_FLAG;
+		return internal->has_flag;
 	}
 
 	inline bool Tile::isOpened() {
-		return *internal & TILE_OPENED;
+		return internal->is_opened;
 	}
 
 	inline std::vector<Tile> Tile::adjacentTiles() {
-		uint8_t *tiles[8];
+		minesweeper_tile *tiles[8];
 		minesweeper_get_adjacent_tiles(game, internal, tiles);
 		std::vector<Tile> list;
 
 		for (int i = 0; i < 8; i++) {
-			uint8_t *tilePtr = tiles[i];
+			minesweeper_tile *tilePtr = tiles[i];
 			if (tilePtr != NULL) {
 				list.push_back(Tile(tilePtr, this->game));
 			}