diff --git a/g.py b/g.py
index e30e095..64d1041 100644
--- a/g.py
+++ b/g.py
@@ -15,8 +15,6 @@ context: tcod.context.Context
 world: tcod.ecs.Registry
 """The active ECS registry and current session."""
 
-world_center: tuple[int,int] = Position(50, 50)
-
 screens: list[Screen] = []
 """A stack of states with the last item being the active state."""
 
diff --git a/game/screens/game_screens.py b/game/screens/game_screens.py
index e9bc948..0075be1 100644
--- a/game/screens/game_screens.py
+++ b/game/screens/game_screens.py
@@ -16,7 +16,7 @@ from game.screens import Push, Screen, ScreenResult
 from game.tags import IsItem, IsPlayer, IsDoor, IsActor
 from game.constants import WALL_CHAR
 from game.screens import menu_screens
-
+from game.world_tools import world_pos_to_map_pos, map_pos_to_world_pos
 
 @attrs.define()
 class MainScreen(Screen):
@@ -34,7 +34,8 @@ class MainScreen(Screen):
                 raise SystemExit()
             case tcod.event.KeyDown(sym=sym) if sym in DIRECTION_KEYS:
                 new_pos = player.components[Position] + DIRECTION_KEYS[sym]
-                if not g.world[None].components[Map].walkable[g.world_center.y+new_pos.y][g.world_center.x+new_pos.x]:
+                map_pos = world_pos_to_map_pos(new_pos)
+                if not g.world[None].components[Map].walkable[map_pos.y][map_pos.x]:
                     return None
                 player.components[Position] = new_pos
                 # Auto pickup gold
@@ -56,20 +57,37 @@ class MainScreen(Screen):
         camera_pos = camera_pos.mod(len(centers))
         h = console.height//2
         w = console.width//2
+
+        map: Map = g.world[None].components[Map]
+        cam_map = world_pos_to_map_pos(camera_pos)
+        map.compute_fov(cam_map.x, cam_map.y, 100)
+
         def draw(e_pos, e_graph):
             screen_pos = e_pos - camera_pos
+            map_pos = world_pos_to_map_pos(e_pos)
             if (-w <= screen_pos.x < w\
                 and -h <= screen_pos.y < h):
-                graphic = e_graph
+                if map.fov[map_pos.y][map_pos.x]:
+                    graphic = e_graph
+                else:
+                    graphic = Graphic(0x2591, (50, 50, 50))
                 console.rgb[["ch", "fg"]][screen_pos.y + h, screen_pos.x + w] = graphic.ch, graphic.fg
-        for (y, row) in enumerate(g.world[None].components[Map].walkable):
+
+        # Draw walls
+        for (y, row) in enumerate(map.walkable):
             for (x, val) in enumerate(row):
-                if not val:
-                    draw(Position(x,y)-g.world_center, Graphic(WALL_CHAR))
+                pos = map_pos_to_world_pos(Position(x,y))
+                if val:
+                    draw(pos, Graphic(0)) # open air
+                else:
+                    draw(pos, Graphic(WALL_CHAR))
+        # draw all entities that are not actors
         for entity in g.world.Q.all_of(components=[Position, Graphic]).none_of(tags=[IsActor]):
             draw(entity.components[Position], entity.components[Graphic])
+        # draw all actors
         for actor in g.world.Q.all_of(components=[Position, Graphic], tags=[IsActor]).none_of(tags=[IsPlayer]):
             draw(actor.components[Position], entity.components[Graphic])
+        # draw the player
         for player in g.world.Q.all_of(tags=[IsPlayer]):
             draw(player.components[Position], player.components[Graphic])
         if text := g.world[None].components.get(("Text", str)):
diff --git a/game/world_tools.py b/game/world_tools.py
index fc7022e..74a6783 100644
--- a/game/world_tools.py
+++ b/game/world_tools.py
@@ -1,38 +1,45 @@
 """Functions for working with worlds."""
 
 from __future__ import annotations
-
 from random import Random
-
-import g
+from typing import Final
 
 from tcod.ecs import Registry, Entity
 from tcod.map import Map
 
+import g
+
 from game.components import Gold, Graphic, Position
 from game.tags import IsActor, IsItem, IsPlayer, IsDoor
 
-def add_wall(pos, remove=False):
-    r_pos = g.world_center + pos
-    map = g.world[None].components[Map]
+world_center: Final = Position(50, 50)
+
+def world_pos_to_map_pos(pos):
+    return pos+world_center
+
+def map_pos_to_world_pos(pos):
+    return pos-world_center
+
+def add_wall(world, pos, remove=False):
+    r_pos = world_pos_to_map_pos(pos)
+    map = world[None].components[Map]
     map.walkable[r_pos.y][r_pos.x] = remove
     map.transparent[r_pos.y][r_pos.x] = remove
 
-def add_door(pos):
-    g.world.new_entity(
+def add_door(world, pos):
+    world.new_entity(
         components={
             Position: pos,
             Graphic: Graphic(ord('\\'))
         },
         tags=[IsDoor]
     )
-    add_wall(pos)
+    add_wall(world, pos)
 
 
 def new_world() -> Registry:
     """Return a freshly generated world."""
     world = Registry()
-    g.world = world
 
     map = world[None].components[Map] = Map(100, 100)
     map.walkable[:] = True
@@ -66,9 +73,9 @@ def new_world() -> Registry:
 
     for i in range(20):
         if i == 5 or i == 9:
-            add_door(Position(10,i))
+            add_door(world, Position(10,i))
         else:
-            add_wall(Position(10, i))
+            add_wall(world, Position(10, i))
 
     return world
 
@@ -76,4 +83,4 @@ def new_world() -> Registry:
 def unlock_door(door: Entity):
     door.components[Graphic] = Graphic(ord("_"))
     door.tags.clear()
-    add_wall(door.components[Position], remove=True)
+    add_wall(g.world, door.components[Position], remove=True)
diff --git a/main.py b/main.py
index 226a327..cfb479e 100755
--- a/main.py
+++ b/main.py
@@ -17,7 +17,7 @@ def main() -> None:
     tileset = tcod.tileset.load_tilesheet(
         "data/Alloy_curses_12x12.png", columns=16, rows=16, charmap=tcod.tileset.CHARMAP_CP437
     )
-    tcod.tileset.procedural_block_elements(tileset=tileset)
+    #tcod.tileset.procedural_block_elements(tileset=tileset)
 
     g.screens = [MainMenu()]
     g.console = tcod.console.Console(80, 50)