clean up terrain and animal api for doing path finding

.gitignore

@@ -1 +1,2 @@
 .DS_Store
+*.swp

lib/animal.rb

@@ -5,6 +5,13 @@ class Animal
   key :y, Integer
   key :species, String
 
+  def find_path_to(other)
+    path = Path.new(:start => self, :goal => other)
+    path.calculate
+    path.save
+    path
+  end
+
   def step
     case rand(4)
       when 0: self.x = x + 1;

lib/path.rb

@@ -6,7 +6,7 @@ class Path
   many :nodes
 
   def build_nodes
-    @terrain = Terrain.all("$where" => "(this.x >= #{start.x} || this.x <= #{goal.x}) && (this.y >= #{start.y} || this.y <= #{goal.y})")
+    @terrain = Terrain.within(start, goal)
     @node_grid = []
     @width  = goal.x - start.x + 1
     @height = goal.y - start.y + 1

lib/terrain.rb

@@ -9,8 +9,8 @@ def no_overlapping_terrain
     end
   end
 
-  def self.within(x_start, y_start, x_end, y_end)
-    all("$where" => "(this.x >= #{x_start} || this.x <= #{x_end}) && (this.y >= #{y_start} || this.y <= #{y_end})")
+  def self.within(start, finish)
+    all("$where" => "(this.x >= #{start.x} || this.x <= #{finish.x}) && (this.y >= #{start.y} || this.y <= #{finish.y})")
   end
 
   key :x, Integer