+ ##
+ # raised when user input couldn't be parsed
+ class APIBadUserInput < APIError
+ def initialize(message)
+ @message = message
+ end
+
+ def status
+ :bad_request
+ end
+
+ def to_s
+ @message
+ end
+ end
+
+ ##
+ # raised when bounding box is invalid
+ class APIBadBoundingBox < APIError
+ def initialize(message)
+ @message = message
+ end
+
+ def status
+ :bad_request
+ end
+
+ def to_s
+ @message
+ end
+ end
+
+ ##
+ # raised when an API call is made using a method not supported on that URI
+ class APIBadMethodError < APIError
+ def initialize(supported_method)
+ @supported_method = supported_method
+ end
+
+ def status
+ :method_not_allowed
+ end
+
+ def to_s
+ "Only method #{@supported_method} is supported on this URI"
+ end
+ end
+
+ ##
+ # raised when an API call takes too long
+ class APITimeoutError < APIError
+ def status
+ :request_timeout
+ end
+
+ def to_s
+ "Request timed out"
+ end
+ end
+
+ # Helper methods for going to/from mercator and lat/lng.
+ class Mercator
+ include Math
+
+ #init me with your bounding box and the size of your image
+ def initialize(min_lat, min_lon, max_lat, max_lon, width, height)
+ xsize = xsheet(max_lon) - xsheet(min_lon)
+ ysize = ysheet(max_lat) - ysheet(min_lat)
+ xscale = xsize / width
+ yscale = ysize / height
+ scale = [xscale, yscale].max
+
+ xpad = width * scale - xsize
+ ypad = height * scale - ysize
+
+ @width = width
+ @height = height
+
+ @tx = xsheet(min_lon) - xpad / 2
+ @ty = ysheet(min_lat) - ypad / 2
+
+ @bx = xsheet(max_lon) + xpad / 2
+ @by = ysheet(max_lat) + ypad / 2
+ end
+
+ #the following two functions will give you the x/y on the entire sheet
+
+ def ysheet(lat)
+ log(tan(PI / 4 + (lat * PI / 180 / 2))) / (PI / 180)
+ end
+
+ def xsheet(lon)
+ lon
+ end
+
+ #and these two will give you the right points on your image. all the constants can be reduced to speed things up. FIXME
+
+ def y(lat)
+ return @height - ((ysheet(lat) - @ty) / (@by - @ty) * @height)
+ end
+
+ def x(lon)
+ return ((xsheet(lon) - @tx) / (@bx - @tx) * @width)
+ end
+ 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
+ @doc.encoding = XML::Encoding::UTF_8
+
+ rss = XML::Node.new 'rss'
+ @doc.root = rss
+ rss['version'] = "2.0"
+ rss['xmlns:geo'] = "http://www.w3.org/2003/01/geo/wgs84_pos#"
+ @channel = XML::Node.new 'channel'
+ rss << @channel
+ title = XML::Node.new 'title'
+ title << feed_title
+ @channel << title
+ description_el = XML::Node.new 'description'
+ @channel << description_el
+
+ description_el << feed_description
+ link = XML::Node.new 'link'
+ link << feed_url
+ @channel << link
+ image = XML::Node.new 'image'
+ @channel << image
+ url = XML::Node.new 'url'
+ url << 'http://www.openstreetmap.org/images/mag_map-rss2.0.png'
+ image << url
+ title = XML::Node.new 'title'
+ title << "OpenStreetMap"
+ image << title
+ width = XML::Node.new 'width'
+ width << '100'
+ image << width
+ height = XML::Node.new 'height'
+ height << '100'
+ image << height
+ link = XML::Node.new 'link'
+ link << feed_url
+ image << link
+ end
+
+ def add(latitude=0, longitude=0, title_text='dummy title', author_text='anonymous', url='http://www.example.com/', description_text='dummy description', timestamp=DateTime.now)
+ item = XML::Node.new 'item'
+
+ title = XML::Node.new 'title'
+ item << title
+ title << title_text
+ link = XML::Node.new 'link'
+ link << url
+ item << link
+
+ guid = XML::Node.new 'guid'
+ guid << url
+ item << guid
+
+ description = XML::Node.new 'description'
+ description << description_text
+ item << description
+
+ author = XML::Node.new 'author'
+ author << author_text
+ item << author
+
+ pubDate = XML::Node.new 'pubDate'
+ pubDate << timestamp.to_s(:rfc822)
+ item << pubDate
+
+ if latitude
+ lat_el = XML::Node.new 'geo:lat'
+ lat_el << latitude.to_s
+ item << lat_el