X-Git-Url: https://git.openstreetmap.org/rails.git/blobdiff_plain/7f2756fe204ba728c2cb282fb0e372be1afc317f..b13eb8824e29a7a0caddab76703fddb00e17a227:/lib/osm.rb

diff --git a/lib/osm.rb b/lib/osm.rb
index 40ec9da3d..77b07ce3d 100644
--- a/lib/osm.rb
+++ b/lib/osm.rb
@@ -69,13 +69,13 @@ module OSM
     attr_reader :tracksegs
 
     def initialize(filename)
+      @filename = filename
+    end
+
+    def points
       @possible_points = 0
       @actual_points = 0
       @tracksegs = 0
-      @points = []
-
-      file = File.new(filename)
-      parser = REXML::Parsers::SAX2Parser.new( file )
 
       lat = -1
       lon = -1
@@ -85,6 +85,8 @@ module OSM
       gotele = false
       gotdate = false
 
+      parser = REXML::Parsers::SAX2Parser.new(File.new(@filename))
+
       parser.listen( :start_element,  %w{ trkpt }) do |uri,localname,qname,attributes| 
         lat = attributes['lat'].to_f
         lon = attributes['lon'].to_f
@@ -99,8 +101,11 @@ module OSM
 
       parser.listen( :characters, %w{ time } ) do |text|
         if text && text != ''
-          date = DateTime.parse(text)
-          gotdate = true
+          begin
+            date = DateTime.parse(text)
+            gotdate = true
+          rescue
+          end
         end
       end
 
@@ -113,18 +118,15 @@ module OSM
           ele = '0' unless gotele
           if lat < 90 && lat > -90 && lon > -180 && lon < 180
             @actual_points += 1
-            @points.push(Hash['latitude' => lat,'longitude' => lon,'timestamp' => date,'altitude' => ele,'segment' => @tracksegs])
+            yield Hash['latitude' => lat, 'longitude' => lon, 'timestamp' => date, 'altitude' => ele, 'segment' => @tracksegs]
           end
         end
         gotlatlon = false
         gotele = false
         gotdate = false
       end
-      parser.parse
-    end
 
-    def points
-      @points.each { |p| yield p }
+      parser.parse
     end
 
     def get_picture(min_lat, min_lon, max_lat, max_lon, num_points)
@@ -241,6 +243,34 @@ module OSM
 
   end
 
+  class GreatCircle
+    include Math
+
+    # initialise with a base position
+    def initialize(lat, lon)
+      @lat = lat * PI / 180
+      @lon = lon * PI / 180
+    end
+
+    # get the distance from the base position to a given position
+    def distance(lat, lon)
+      lat = lat * PI / 180
+      lon = lon * PI / 180
+      return 6372.795 * 2 * asin(sqrt(sin((lat - @lat) / 2) ** 2 + cos(@lat) * cos(lat) * sin((lon - @lon)/2) ** 2))
+    end
+
+    # get the worst case bounds for a given radius from the base position
+    def bounds(radius)
+      latradius = 2 * asin(sqrt(sin(radius / 6372.795 / 2) ** 2))
+      lonradius = 2 * asin(sqrt(sin(radius / 6372.795 / 2) ** 2 / cos(@lat) ** 2))
+      minlat = (@lat - latradius) * 180 / PI
+      maxlat = (@lat + latradius) * 180 / PI
+      minlon = (@lon - lonradius) * 180 / PI
+      maxlon = (@lon + lonradius) * 180 / PI
+      return { :minlat => minlat, :maxlat => maxlat, :minlon => minlon, :maxlon => maxlon }
+    end
+  end
+
   class GeoRSS
     def initialize(feed_title='OpenStreetMap GPS Traces', feed_description='OpenStreetMap GPS Traces', feed_url='http://www.openstreetmap.org/traces/')
       @doc = XML::Document.new