anchor.diff:  	case bc_entities:entity_config(EntityType) of
   		{ok, BcEntityConfig} ->
   			{ok, BaseNum, State1} = player_num(State),
  -			{ok, SpawnBcVertices, State2} = spawn_vertices(State1),
  +			{ok, SpawnBcVertices, State2} = spawn_matrix(State1),
   			spawn_entities(EntityType, State2),
   			{ok, State2};
   		error ->
  
positive.code: %%====================================================================
  %% Internal functions
  %%====================================================================
  
  spawn_entities(BcEntityConfig, #state{entities = BcEntities,
  								  map = BcMap,
  								  spawn_vertices = BcVertices} = State) ->
  	EntitySize = bc_entity_config:size(BcEntityConfig),
  	QueryRes = bc_map:query_collisions(BcMap, BcVertices),
  	%% TODO spawn entities
  	ok.
  
  base_num(BaseBcVertices, BcMap) ->
  	BaseBcVertex = lists:nth(1, BaseBcVertices),
  
negative.code: 			{ok, Num, State}
  	end.
  
  %% do_spawn_entities(BcEntityConfig, SpawnBcVertices, BatchCount, 
  %% 				  #state{entities = BcEntities,
  %% 						 map = BcMap,
  %% 						 base_num = BaseNum,
  %% 						 spawn_matrix = BcMatrix} = State) ->
  %% 	SpawnBcVertices = spawn_vertices(Offset, State),
  %% 	EntitySize = bc_entity_config:size(BcEntityConfig),
  %% 	BatchSize = length(SpawnBcVertices) / EntitySize,
  %% 	
  %% 
  %% spawn_entities(BcEntityConfig, #state{entities = BcEntities,
  %% 								  	  map = BcMap,
  %% 									  base_num = BaseNum,
  %% 								  	  spawn_matrix = BcMatrix} = State) ->
  %% 	
  %% 	%% TODO spawn entities
  %% 	ok.
  
  spawn_vertices(Offset, #state{base_num = BaseNum,
  					  		  spawn_matrix = SpawnBcMatrix} = State) ->
  	case BaseNum of
  		1 -> 
  			MinRow = bc_matrix:min_row(SpawnBcMatrix),
  			bc_matrix:row(MinRow + Offset, SpawnBcMatrix);
  		2 ->
  			MaxCol = bc_matrix:max_col(SpawnBcMatrix),
  			bc_matrix:col(MaxCol - Offset, SpawnBcMatrix);
  		3 ->
  			MaxRow = bc_matrix:max_row(SpawnBcMatrix),
  			bc_matrix:row(MaxRow - Offset, SpawnBcMatrix);
  		4 ->
  			MinCol = bc_matrix:min_col(SpawnBcMatrix),
  			bc_matrix:col(MinCol + Offset, SpawnBcMatrix)
  	end.
  
  spawn_matrix(#state{base_num = BaseNum,
  					spawn_matrix = SpawnBcMatrix,
  					map = BcMap} = State) ->
  	case SpawnBcMatrix of
  		undefined ->
  			BcVertices = case BaseNum of
  							 1 -> bc_map:base1_spawn_vertices(BcMap);
  