3 files changed, 102 insertions, 1 deletions

diff --git a/src/struct/battlemap.erl b/src/struct/battlemap.erl
index 8f85bbb..9204084 100644
--- a/src/struct/battlemap.erl
+++ b/src/struct/battlemap.erl
@@ -30,7 +30,8 @@
       get_id/1,
       get_width/1,
       get_height/1,
-      get_tile_ids/1
+      get_tile_ids/1,
+      get_tile_id/2
    ]
 ).
 
@@ -65,6 +66,20 @@ generate_random_tile_ids (PreviousTileID, Result, X, Y, Width) ->
       end,
    generate_random_tile_ids(NewTile, [NewTile|Result], (X - 1), Y, Width).
 
+-spec location_to_array_index
+   (
+      non_neg_integer(),
+      location:type()
+   )
+   -> ('error' | non_neg_integer()).
+location_to_array_index (ArrayWidth, {X, Y}) ->
+   if
+      (X < 0) -> error;
+      (Y < 0) -> error;
+      (X >= ArrayWidth) -> error;
+      true -> ((Y * ArrayWidth) + X)
+   end.
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% EXPORTED FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -81,6 +96,11 @@ get_height (Battlemap) -> Battlemap#battlemap.height.
 -spec get_tile_ids (struct()) -> array:array(tile:id()).
 get_tile_ids (Battlemap) -> Battlemap#battlemap.tile_ids.
 
+-spec get_tile_id (location:type(), struct()) -> tile:id().
+get_tile_id (Location, Battlemap) ->
+   TileIX = location_to_array_index(Battlemap#battlemap.width, Location),
+   array:get(TileIX, Battlemap#battlemap.tile_ids).
+
 -spec random
    (
       non_neg_integer(),
diff --git a/src/struct/direction.erl b/src/struct/direction.erl
new file mode 100644
index 0000000..074cadf
--- /dev/null
+++ b/src/struct/direction.erl
@@ -0,0 +1,36 @@
+-module(direction).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% TYPES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-type enum() :: ('up' | 'down' | 'left' | 'right').
+
+-export_type([enum/0]).
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-export
+(
+   [
+      from_binary/1,
+      to_binary/1
+   ]
+).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% LOCAL FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTED FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-spec from_binary (binary()) -> enum().
+from_binary (<<"U">>) -> up;
+from_binary (<<"D">>) -> down;
+from_binary (<<"L">>) -> left;
+from_binary (<<"R">>) -> right.
+
+to_binary (up) -> <<"U">>;
+to_binary (down) -> <<"D">>;
+to_binary (left) -> <<"L">>;
+to_binary (right) -> <<"R">>.
diff --git a/src/struct/location.erl b/src/struct/location.erl
new file mode 100644
index 0000000..624fe56
--- /dev/null
+++ b/src/struct/location.erl
@@ -0,0 +1,45 @@
+-module(location).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% TYPES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-type type() :: {non_neg_integer(), non_neg_integer()}.
+
+-export_type([type/0]).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-export
+(
+   [
+      apply_direction/2,
+      dist/2
+   ]
+).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% LOCAL FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-spec validate ({integer(), integer()}) -> type().
+validate ({X, Y}) ->
+   true = (X >= 0),
+   true = (Y >= 0),
+   {X, Y}.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTED FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-spec apply_direction (direction:enum(), type()) -> type().
+apply_direction (left, {X, Y}) ->
+   validate({(X - 1), Y});
+apply_direction (right, {X, Y}) ->
+   validate({(X + 1), Y});
+apply_direction (up, {X, Y}) ->
+   validate({X, (Y - 1)});
+apply_direction (down, {X, Y}) ->
+   validate({X, (Y + 1)}).
+
+-spec dist(type(), type()) -> non_neg_integer().
+dist ({OX, OY}, {DX, DY}) ->
+   (abs(DY - OY) + abs(DX - OX)).