diff --git a/lib/wave_function_collapse/cell.rb b/lib/wave_function_collapse/cell.rb
index e5b7a0f..50afe02 100644
--- a/lib/wave_function_collapse/cell.rb
+++ b/lib/wave_function_collapse/cell.rb
@@ -33,14 +33,15 @@ def collapse
       self.tiles = [@tiles.max_by { |t| rand**(1.0 / t.probability) }]
     end
 
-    def neighbors(grid)
-      return if grid.nil?
-
-      @neighbors["#{@x},#{@y}"] ||= begin
-        up = grid[@x][@y + 1] if grid[@x] && @y < grid[0].length - 1
-        down = grid[@x][@y - 1] if grid[@x] && @y.positive?
-        right = grid[@x + 1][@y] if @x < grid.length - 1
-        left = grid[@x - 1][@y] if @x.positive?
+    def neighbors(model)
+      return if model.nil?
+
+      @neighbors[model.width * y + x] ||= begin
+        up = model.cell_at(@x, @y + 1) if @y < model.height - 1
+        down = model.cell_at(@x, @y - 1) if @y.positive?
+        right = model.cell_at(@x + 1, @y) if @x < model.width - 1
+        left = model.cell_at(@x - 1, @y) if @x.positive?
+
         {up: up, down: down, right: right, left: left}
       end
     end
diff --git a/lib/wave_function_collapse/model.rb b/lib/wave_function_collapse/model.rb
index 012efa6..76b3e2d 100644
--- a/lib/wave_function_collapse/model.rb
+++ b/lib/wave_function_collapse/model.rb
@@ -22,12 +22,16 @@ def initialize(tiles, width, height)
       @tiles = tiles
       @width = width.to_i
       @height = height.to_i
-
-      @grid = Array.new(width) { |x| Array.new(height) { |y| Cell.new(x, y, @tiles.shuffle) } }
-      @uncollapsed_cells_grid = @grid.flatten.reject(&:collapsed)
+      @grid = []
+      @height.times { |y| @width.times { |x| @grid << Cell.new(x, y, @tiles.shuffle) } }
+      @uncollapsed_cells_grid = @grid.reject(&:collapsed)
       @max_entropy = @tiles.length
     end
 
+    def cell_at(x, y)
+      @grid[@width * y + x]
+    end
+
     def complete?
       @uncollapsed_cells_grid.empty?
     end
@@ -79,18 +83,18 @@ def random_cell
     def generate_grid
       x = 0
       result = []
-      lx = @grid.length
-      while x < lx
+
+      while x < @width
         rx = result[x] = []
         y = 0
-        pgx = @grid[x]
-        ly = pgx.length
-        while y < ly
-          rx[y] = pgx[y].tile
+
+        while y < @height
+          rx[y] = cell_at(x, y).tile
           y += 1
         end
         x += 1
       end
+
       result
     end
 
@@ -110,7 +114,7 @@ def propagate(source_cell)
     end
 
     def evaluate_neighbor(source_cell, evaluation_direction)
-      neighbor_cell = source_cell.neighbors(@grid)[evaluation_direction]
+      neighbor_cell = source_cell.neighbors(self)[evaluation_direction]
       return if neighbor_cell.nil? || neighbor_cell.collapsed
 
       original_tile_count = neighbor_cell.tiles.length
@@ -122,16 +126,19 @@ def evaluate_neighbor(source_cell, evaluation_direction)
       neighbor_tiles = neighbor_cell.tiles
       sci = 0
       scil = source_tiles.length
+
       while sci < scil
         source_tile = source_tiles[sci]
         sci += 1
         source_edge_hash = source_tile.send(evaluation_direction)
         nci = 0
         ncil = neighbor_tiles.length
+
         while nci < ncil
           tile = neighbor_tiles[nci]
           nci += 1
           next if new_tile_ids.has_key?(tile.tileid)
+
           tile_edge_hash = tile.send(opposite_direction)
           if tile_edge_hash == source_edge_hash
             new_tile_ids[tile.tileid] = true
@@ -139,6 +146,7 @@ def evaluate_neighbor(source_cell, evaluation_direction)
           end
         end
       end
+
       neighbor_cell.tiles = new_tiles unless new_tiles.empty?
       @uncollapsed_cells_grid.delete(neighbor_cell) if neighbor_cell.collapsed
 
diff --git a/lib/wave_function_collapse/window.rb b/lib/wave_function_collapse/window.rb
index fb4eecf..5d3ba72 100644
--- a/lib/wave_function_collapse/window.rb
+++ b/lib/wave_function_collapse/window.rb
@@ -121,7 +121,7 @@ def draw_map
         column.reverse.each_with_index do |tile, y|
           inverted_y = (y - @model.height + 1).abs
 
-          entropy = @model.grid[x][inverted_y].entropy
+          entropy = @model.cell_at(x, inverted_y).entropy
 
           if entropy > 1
             percent_entropy = (entropy.to_f / @model.max_entropy * 255).round
diff --git a/test/test_model.rb b/test/test_model.rb
index cbbecff..8d042a5 100644
--- a/test/test_model.rb
+++ b/test/test_model.rb
@@ -13,7 +13,7 @@ def test_initialize
 
     assert_equal 320, model.width
     assert_equal 240, model.height
-    assert_equal 320 * 240, model.grid.map(&:size).sum
+    assert_equal 320 * 240, model.grid.size
     assert_equal 3, model.max_entropy
     assert_equal 0, model.percent
     refute model.complete?