provide Snake POV control option in Menuconfig

src/animations/config.in

@@ -9,7 +9,6 @@ comment "Animations"
 	bool     "Joern1"        ANIMATION_JOERN1
 
 	dep_bool_menu "Snake"    ANIMATION_SNAKE         $RANDOM_SUPPORT
-		int  "Snake Game Round Delay"   SNAKE_GAME_DELAY        200
 		int  "Snake Anim Round Delay"   SNAKE_ANIM_DELAY        100
 		int  "Snake Termination Delay"  SNAKE_TERMINATION_DELAY  60
 		uint "Snake Max Length"         SNAKE_MAX_LENGTH         64

src/games/config.in

@@ -7,7 +7,13 @@ comment "Games"
 	endmenu
 	
 	dep_bool "Space Invaders" GAME_SPACE_INVADERS $JOYSTICK_SUPPORT $RANDOM_SUPPORT
-	dep_bool "Snake"          GAME_SNAKE          $JOYSTICK_SUPPORT $RANDOM_SUPPORT
+
+	dep_bool_menu "Snake"  GAME_SNAKE y $JOYSTICK_SUPPORT $RANDOM_SUPPORT
+		bool "POV Controls"           SNAKE_POV_CONTROL n
+		int  "Snake Game Round Delay" SNAKE_GAME_DELAY  200
+	endmenu
+
 	dep_bool "Breakout"       GAME_BREAKOUT       $JOYSTICK_SUPPORT $RANDOM_SUPPORT
+
 	dep_bool "Kart"       	  GAME_KART           $JOYSTICK_SUPPORT $RANDOM_SUPPORT
 endmenu

src/games/snake/snake_game.c

@@ -37,11 +37,13 @@ game_descriptor_t snake_game_descriptor __attribute__((section(".game_descriptor
 #endif
 
 
-/**
- * If defined, joystick controls are NOT as "seen" by the snake but absolute,
- * that is, if pressing up, snake goes up, etc.
- */
-#define SNAKE_NEWCONTROL
+#ifdef DOXYGEN
+	/**
+	 * If defined, joystick controls are bound to the point of view of the
+	 * snake, i.e. only the left an right joystick direction can be used.
+	 */
+	#define SNAKE_POV_CONTROL
+#endif
 
 #if !defined USNAKE_MAX_LENGTH || defined DOXYGEN
 	/** The maximum length of the snake. */
@@ -229,35 +231,37 @@ static void snake_userControl(snake_protagonist_t *pprotSnake,
                               snake_dir_t *pdirLast)
 {
 	snake_dir_t dirJoystick = snake_queryJoystick();
-#ifdef SNAKE_NEWCONTROL
-	if (dirJoystick != SNAKE_DIR_NONE)
+#	ifdef SNAKE_POV_CONTROL
+
+	if ((dirJoystick ^ *pdirLast) && (dirJoystick != SNAKE_DIR_NONE) &&
+			(!pprotSnake->bJoystickLocked))
 	{
-		// valid transitions can only be uneven
-		if (((pprotSnake->dir + dirJoystick) & 0x01) &&
-				!pprotSnake->bJoystickLocked)
+		// only left or right movements are valid
+		if (dirJoystick & 0x01)
 		{
-			pprotSnake->dir = dirJoystick;
+			// rotate through directions (either clockwise or counterclockwise)
+			pprotSnake->dir = (pprotSnake->dir +
+					(dirJoystick == SNAKE_DIR_LEFT ? 3 : 1)) % 4u;
 		}
 		// we query the joystick twice as fast as we move the snake, so we
 		// have to ensure that it does not bite its head with its head...uh
 		pprotSnake->bJoystickLocked = true;
 	}
-#else
-	if ((dirJoystick ^ *pdirLast) && (dirJoystick != SNAKE_DIR_NONE))
+	*pdirLast = dirJoystick;
+#	else
+	if (dirJoystick != SNAKE_DIR_NONE)
 	{
-		// only left or right movements are valid
-		if (dirJoystick & 0x01)
+		// valid transitions can only be uneven
+		if (((pprotSnake->dir + dirJoystick) & 0x01) &&
+				!pprotSnake->bJoystickLocked)
 		{
-			// rotate through directions (either clockwise or counterclockwise)
-			pprotSnake->dir = (pprotSnake->dir +
-					(dirJoystick == SNAKE_DIR_LEFT ? 3 : 1)) % 4u;
+			pprotSnake->dir = dirJoystick;
 		}
 		// we query the joystick twice as fast as we move the snake, so we
 		// have to ensure that it does not bite its head with its head...uh
 		pprotSnake->bJoystickLocked = true;
 	}
-	*pdirLast = dirJoystick;
-#endif
+#	endif
 }
 #endif