lib/terraformer/feature.rb in terraformer-0.0.1 vs lib/terraformer/feature.rb in terraformer-0.0.2

@@ -1,12 +1,15 @@
 module Terraformer
 
   class Feature < Primitive
+    extend Forwardable
 
     attr_accessor :id, :geometry
     attr_writer :properties
 
+    def_delegator :@geometry, :convex_hull
+
     def initialize *args
       unless args.empty?
         super *args do |arg|
           self.id = arg['id'] if arg.key? 'id'
           self.properties = arg['properties'] if arg.key? 'properties'
@@ -27,16 +30,28 @@
       }
       h.merge! id: id if id
       h
     end
 
+    def great_circle_distance other
+      other = other.geometry if Feature === other
+      self.geometry.great_circle_distance other
+    end
+
   end
 
   class FeatureCollection < Primitive
 
     attr_writer :features
 
+    def self.with_features *f
+      raise ArgumentError unless f.all? {|e| Feature === e}
+      fc = FeatureCollection.new
+      fc.features = f
+      fc
+    end
+
     def initialize *args
       unless args.empty?
         super *args do |arg|
           self.features = arg['features'].map {|f| Terraformer.parse f}
         end
@@ -45,14 +60,23 @@
 
     def features
       @features ||= []
     end
 
+    def << feature
+      raise ArgumentError unless Feature === feature
+      features << feature
+    end
+
     def to_hash
       {
         type: type,
         features: features.map(&:to_hash)
       }
+    end
+
+    def convex_hull
+      ConvexHull.for features.map(&:geometry).map(&:coordinates)
     end
 
   end
 
 end