Adds prevention from passive monsters being "dodgy"

When player gets close to passive monsters they will stop moving now.
This should prevent annoying behaviour when trying to line up a strike.

src/map.c

@@ -152,6 +152,13 @@ map_move_monsters(Map *map, RoomMatrix *rm)
 			continue;
 		if (!position_in_room(&monster->sprite->pos, &map->currentRoom))
 			continue;
+
+		// Prevent passive monsters from being "dodgy"
+		Position pos = position_to_matrix_coords(&monster->sprite->pos);
+		if (monster->state.current == PASSIVE
+		    && position_proximity(1, &rm->playerRoomPos, &pos))
+			continue;
+
 		allDone = allDone && monster_move(monster, rm);
 	}
 

src/position.c

@@ -16,6 +16,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <stdlib.h>
 #include "position.h"
 #include "defines.h"
 
@@ -55,6 +56,19 @@ position_equals(const Position *p1, const Position *p2)
 	return p1->x == p2->x && p1->y == p2->y;
 }
 
+bool
+position_proximity(unsigned int distance,
+		   const Position *p1,
+		   const Position *p2)
+{
+	unsigned int dx, dy;
+
+	dx = abs(p1->x - p2->x);
+	dy = abs(p1->y - p2->y);
+
+	return dx <= distance && dy <= distance;
+}
+
 bool
 position_in_room(Position *pos, Position *roomPos)
 {

src/position.h

@@ -38,6 +38,9 @@ position_in_room(Position *pos, Position *roomPos);
 bool
 position_equals(const Position*, const Position*);
 
+bool
+position_proximity(unsigned int distance, const Position*, const Position*);
+
 bool
 position_in_roommatrix(const Position*);