+ helper :user
+ model :user
+
+ #COUNT is the number of map requests to allow before exiting and starting a new process
+ @@count = COUNT
+
+ # The maximum area you're allowed to request, in square degrees
+ MAX_REQUEST_AREA = 0.25
+
+
+ # Number of GPS trace/trackpoints returned per-page
+ TRACEPOINTS_PER_PAGE = 5000
+
+ def trackpoints
+ @@count+=1
+ response.headers["Content-Type"] = 'text/xml'
+ #retrieve the page number
+ page = params['page'].to_i
+ unless page
+ page = 0;
+ end
+
+ unless page >= 0
+ report_error("Page number must be greater than or equal to 0")
+ return
+ end
+
+ offset = page * TRACEPOINTS_PER_PAGE
+
+ # Figure out the bbox
+ bbox = params['bbox']
+ unless bbox and bbox.count(',') == 3
+ report_error("The parameter bbox is required, and must be of the form min_lon,min_lat,max_lon,max_lat")
+ return
+ end
+
+ bbox = bbox.split(',')
+
+ min_lon = bbox[0].to_f
+ min_lat = bbox[1].to_f
+ max_lon = bbox[2].to_f
+ max_lat = bbox[3].to_f
+
+ # check the bbox is sane
+ unless min_lon <= max_lon
+ report_error("The minimum longitude must be less than the maximum longitude, but it wasn't")
+ return
+ end
+ unless min_lat <= max_lat
+ report_error("The minimum latitude must be less than the maximum latitude, but it wasn't")
+ return
+ end
+ unless min_lon >= -180 && min_lat >= -90 && max_lon <= 180 && max_lat <= 90
+ report_error("The latitudes must be between -90 and 90, and longitudes between -180 and 180")
+ return
+ end
+
+ # check the bbox isn't too large
+ requested_area = (max_lat-min_lat)*(max_lon-min_lon)
+ if requested_area > MAX_REQUEST_AREA
+ report_error("The maximum bbox size is " + MAX_REQUEST_AREA.to_s + ", and your request was too large. Either request a smaller area, or use planet.osm")
+ return
+ end
+
+ # integerise
+ min_lat = min_lat * 1000000
+ max_lat = max_lat * 1000000
+ min_lon = min_lon * 1000000
+ max_lon = max_lon * 1000000
+ # get all the points
+ points = Tracepoint.find(:all, :conditions => ['latitude BETWEEN ? AND ? AND longitude BETWEEN ? AND ?', min_lat.to_i, max_lat.to_i, min_lon.to_i, max_lon.to_i], :select => "DISTINCT *", :offset => offset, :limit => TRACEPOINTS_PER_PAGE, :order => "timestamp DESC" )
+
+ doc = XML::Document.new
+ doc.encoding = 'UTF-8'
+ root = XML::Node.new 'gpx'
+ root['version'] = '1.0'
+ root['creator'] = 'OpenStreetMap.org'
+ root['xmlns'] = "http://www.topografix.com/GPX/1/0/"
+
+ doc.root = root
+
+ track = XML::Node.new 'trk'
+ doc.root << track
+
+ trkseg = XML::Node.new 'trkseg'
+ track << trkseg
+
+ points.each do |point|
+ trkseg << point.to_xml_node()
+ end
+
+ #exit when we have too many requests
+ if @@count > MAX_COUNT
+ render :text => doc.to_s
+ @@count = COUNT
+ exit!
+ end
+
+ render :text => doc.to_s
+
+ end
+