Use stored lats/lons to draw trace images

[rails.git] / lib / gpx.rb

diff --git a/lib/gpx.rb b/lib/gpx.rb
index 274ece7d9a3160e6eba8f194fcbe6eb7956bffbc..021971c363a8aaa37a50eaa26fd32b92fc0a512d 100644 (file)
--- a/lib/gpx.rb
+++ b/lib/gpx.rb
@@ -6,8 +6,9 @@ module GPX
 
     attr_reader :possible_points, :actual_points, :tracksegs
 
-    def initialize(file)
+    def initialize(file, options = {})
       @file = file
+      @maximum_points = options[:maximum_points] || Float::INFINITY
     end
 
     def parse_file(reader)
@@ -19,6 +20,7 @@ module GPX
           if reader.name == "trkpt"
             point = TrkPt.new(@tracksegs, reader["lat"].to_f, reader["lon"].to_f)
             @possible_points += 1
+            raise FileTooBigError if @possible_points > @maximum_points
           elsif reader.name == "ele" && point
             point.altitude = reader.read_string.to_f
           elsif reader.name == "time" && point
@@ -29,6 +31,8 @@ module GPX
             point.altitude ||= 0
             yield point
             @actual_points += 1
+            @lats << point.latitude
+            @lons << point.longitude
           elsif reader.name == "trkseg"
             @tracksegs += 1
           end
@@ -42,6 +46,8 @@ module GPX
       @possible_points = 0
       @actual_points = 0
       @tracksegs = 0
+      @lats = []
+      @lons = []
 
       begin
         Archive::Reader.open_filename(@file).each_entry_with_data do |entry, data|
@@ -55,7 +61,7 @@ module GPX
         when "application/x-bzip" then io = Bzip2::FFI::Reader.open(@file)
         end
 
-        parse_file(XML::Reader.io(io), &block)
+        parse_file(XML::Reader.io(io, :options => XML::Parser::Options::NOERROR), &block)
       end
     end
 
@@ -92,9 +98,9 @@ module GPX
 
           first = true
 
-          points.each_with_index do |p, pt|
-            px = proj.x(p.longitude)
-            py = proj.y(p.latitude)
+          @actual_points.times do |pt|
+            px = proj.x @lons[pt]
+            py = proj.y @lats[pt]
 
             if (pt >= (points_per_frame * n)) && (pt <= (points_per_frame * (n + 1)))
               pen.thickness = 3
@@ -149,9 +155,9 @@ module GPX
 
         first = true
 
-        points do |p|
-          px = proj.x(p.longitude)
-          py = proj.y(p.latitude)
+        @actual_points.times do |pt|
+          px = proj.x @lons[pt]
+          py = proj.y @lats[pt]
 
           pen.line(px, py, oldpx, oldpy) unless first
 
@@ -172,4 +178,10 @@ module GPX
         longitude >= -180 && longitude <= 180
     end
   end
+
+  class FileTooBigError < RuntimeError
+    def initialise
+      super("GPX File contains too many points")
+    end
+  end
 end