+# The OSM module provides support functions for OSM.
module OSM
- # This piece of magic reads a GPX with SAX and spits out
- # lat/lng and stuff
- #
- # This would print every latitude value:
- #
- # gpx = OSM::GPXImporter.new('somefile.gpx')
- # gpx.points {|p| puts p['latitude']}
-
require 'time'
require 'rexml/parsers/sax2parser'
require 'rexml/text'
require 'digest/md5'
require 'RMagick'
+ # The base class for API Errors.
+ class APIError < RuntimeError
+ end
+
+ # Raised when an API object is not found.
+ class APINotFoundError < APIError
+ end
+
+ # Raised when a precondition to an API action fails sanity check.
+ class APIPreconditionFailedError < APIError
+ end
+
+ # Raised when to delete an already-deleted object.
+ class APIAlreadyDeletedError < APIError
+ end
+
+ # Helper methods for going to/from mercator and lat/lng.
class Mercator
include Math
- def initialize(lat, lon, degrees_per_pixel, width, height)
- #init me with your centre lat/lon, the number of degrees per pixel and the size of your image
- @clat = lat
- @clon = lon
- @degrees_per_pixel = degrees_per_pixel
- @degrees_per_pixel = 0.0000000001 if @degrees_per_pixel < 0.0000000001
+ #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
- @dlon = width / 2 * @degrees_per_pixel
- @dlat = height / 2 * @degrees_per_pixel * cos(@clat * PI / 180)
-
- @tx = xsheet(@clon - @dlon)
- @ty = ysheet(@clat - @dlat)
- @bx = xsheet(@clon + @dlon)
- @by = ysheet(@clat + @dlat)
+ @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 kilometerinpixels
- return 40008.0 / 360.0 * @degrees_per_pixel
- end
-
def ysheet(lat)
- log(tan(PI / 4 + (lat * PI / 180 / 2)))
+ log(tan(PI / 4 + (lat * PI / 180 / 2))) / (PI / 180)
end
def xsheet(lon)
end
end
-
- class GPXImporter
- # FIXME swap REXML for libXML
- attr_reader :possible_points
- attr_reader :actual_points
- attr_reader :tracksegs
-
- def initialize(filename)
- @filename = filename
- end
-
- def points
- @possible_points = 0
- @actual_points = 0
- @tracksegs = 0
-
- lat = -1
- lon = -1
- ele = -1
- date = DateTime.now();
- gotlatlon = false
- 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
- gotlatlon = true
- @possible_points += 1
- end
-
- parser.listen( :characters, %w{ ele } ) do |text|
- ele = text
- gotele = true
- end
-
- parser.listen( :characters, %w{ time } ) do |text|
- if text && text != ''
- begin
- date = DateTime.parse(text)
- gotdate = true
- rescue
- end
- end
- end
-
- parser.listen( :end_element, %w{ trkseg } ) do |uri, localname, qname|
- @tracksegs += 1
- end
-
- parser.listen( :end_element, %w{ trkpt } ) do |uri,localname,qname|
- if gotlatlon && gotdate
- ele = '0' unless gotele
- if lat < 90 && lat > -90 && lon > -180 && lon < 180
- @actual_points += 1
- 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 get_picture(min_lat, min_lon, max_lat, max_lon, num_points)
- #puts "getting picfor bbox #{min_lat},#{min_lon} - #{max_lat},#{max_lon}"
- frames = 10
- width = 250
- height = 250
- rat= Math.cos( ((max_lat + min_lat)/2.0) / 180.0 * 3.141592)
- proj = OSM::Mercator.new((min_lat + max_lat) / 2, (max_lon + min_lon) / 2, (max_lat - min_lat) / width / rat, width, height)
-
- linegc = Magick::Draw.new
- linegc.stroke_linejoin('miter')
- linegc.stroke_width(1)
- linegc.stroke('#BBBBBB')
- linegc.fill('#BBBBBB')
-
- highlightgc = Magick::Draw.new
- highlightgc.stroke_linejoin('miter')
- highlightgc.stroke_width(3)
- highlightgc.stroke('#000000')
- highlightgc.fill('#000000')
-
- images = []
-
- frames.times do
- image = Magick::Image.new(width, height) do |image|
- image.background_color = 'white'
- image.format = 'GIF'
- end
-
- images << image
- end
-
- oldpx = 0.0
- oldpy = 0.0
-
- first = true
-
- m = 0
- mm = 0
- points do |p|
- px = proj.x(p['longitude'])
- py = proj.y(p['latitude'])
-
- if m > 0
- frames.times do |n|
- if n == mm
- gc = highlightgc.dup
- else
- gc = linegc.dup
- end
-
- gc.line(px, py, oldpx, oldpy)
-
- gc.draw(images[n])
- end
- end
-
- m += 1
- if m > num_points.to_f / frames.to_f * (mm+1)
- mm += 1
- end
-
- oldpy = py
- oldpx = px
- end
-
- il = Magick::ImageList.new
-
- images.each do |f|
- il << f
- end
-
- il.delay = 50
- il.format = 'GIF'
-
- return il.to_blob
- end
-
- def get_icon(min_lat, min_lon, max_lat, max_lon)
- #puts "getting icon for bbox #{min_lat},#{min_lon} - #{max_lat},#{max_lon}"
- width = 50
- height = 50
- rat= Math.cos( ((max_lat + min_lat)/2.0) / 180.0 * 3.141592)
- proj = OSM::Mercator.new((min_lat + max_lat) / 2, (max_lon + min_lon) / 2, (max_lat - min_lat) / width / rat, width, height)
-
- gc = Magick::Draw.new
- gc.stroke_linejoin('miter')
- gc.stroke_width(1)
- gc.stroke('#000000')
- gc.fill('#000000')
-
- image = Magick::Image.new(width, height) do |image|
- image.background_color = 'white'
- image.format = 'GIF'
- end
-
- oldpx = 0.0
- oldpy = 0.0
-
- first = true
-
- points do |p|
- px = proj.x(p['longitude'])
- py = proj.y(p['latitude'])
-
- gc.dup.line(px, py, oldpx, oldpy).draw(image) unless first
-
- first = false
- oldpy = py
- oldpx = px
- end
-
- return image.to_blob
- end
-
- end
-
class GreatCircle
include Math
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 = 'UTF-8'
-
+
rss = XML::Node.new 'rss'
@doc.root = rss
rss['version'] = "2.0"
return "#{tilesql} AND #{prefix}latitude BETWEEN #{minlat} AND #{maxlat} AND #{prefix}longitude BETWEEN #{minlon} AND #{maxlon}"
end
+
+
end