openstreetmap-website/lib/gpx.rb
2020-12-16 11:17:51 +00:00

175 lines
4.4 KiB
Ruby

module GPX
class File
require "libxml"
include LibXML
attr_reader :possible_points, :actual_points, :tracksegs
def initialize(file)
@file = file
end
def parse_file(reader)
point = nil
while reader.read
case reader.node_type
when XML::Reader::TYPE_ELEMENT
if reader.name == "trkpt"
point = TrkPt.new(@tracksegs, reader["lat"].to_f, reader["lon"].to_f)
@possible_points += 1
elsif reader.name == "ele" && point
point.altitude = reader.read_string.to_f
elsif reader.name == "time" && point
point.timestamp = Time.parse(reader.read_string)
end
when XML::Reader::TYPE_END_ELEMENT
if reader.name == "trkpt" && point && point.valid?
point.altitude ||= 0
yield point
@actual_points += 1
elsif reader.name == "trkseg"
@tracksegs += 1
end
end
end
end
def points(&block)
return enum_for(:points) unless block
@possible_points = 0
@actual_points = 0
@tracksegs = 0
begin
Archive::Reader.open_filename(@file).each_entry_with_data do |entry, data|
parse_file(XML::Reader.string(data), &block) if entry.regular?
end
rescue Archive::Error
io = ::File.open(@file)
case MimeMagic.by_magic(io)&.type
when "application/gzip" then io = Zlib::GzipReader.open(@file)
when "application/x-bzip" then io = Bzip2::FFI::Reader.open(@file)
end
parse_file(XML::Reader.io(io), &block)
end
end
def picture(min_lat, min_lon, max_lat, max_lon, num_points)
nframes = 10
width = 250
height = 250
delay = 50
points_per_frame = (num_points.to_f / nframes).ceil
proj = OSM::Mercator.new(min_lat, min_lon, max_lat, max_lon, width, height)
frames = []
(0...nframes).each do |n|
frames[n] = GD2::Image::IndexedColor.new(width, height)
black = frames[n].palette.allocate(GD2::Color[0, 0, 0])
white = frames[n].palette.allocate(GD2::Color[255, 255, 255])
grey = frames[n].palette.allocate(GD2::Color[187, 187, 187])
frames[n].draw do |pen|
pen.color = white
pen.rectangle(0, 0, width, height, true)
end
frames[n].draw do |pen|
pen.color = black
pen.anti_aliasing = true
pen.dont_blend = false
oldpx = 0.0
oldpy = 0.0
first = true
points.each_with_index do |p, pt|
px = proj.x(p.longitude)
py = proj.y(p.latitude)
if (pt >= (points_per_frame * n)) && (pt <= (points_per_frame * (n + 1)))
pen.thickness = 3
pen.color = black
else
pen.thickness = 1
pen.color = grey
end
pen.line(px, py, oldpx, oldpy) unless first
first = false
oldpy = py
oldpx = px
end
end
end
image = GD2::AnimatedGif.new
image.add(frames.first)
frames.each do |frame|
image.add(frame, :delay => delay)
end
image.end
output = StringIO.new
image.export(output)
output.read
end
def icon(min_lat, min_lon, max_lat, max_lon)
width = 50
height = 50
proj = OSM::Mercator.new(min_lat, min_lon, max_lat, max_lon, width, height)
image = GD2::Image::IndexedColor.new(width, height)
black = image.palette.allocate(GD2::Color[0, 0, 0])
white = image.palette.allocate(GD2::Color[255, 255, 255])
image.draw do |pen|
pen.color = white
pen.rectangle(0, 0, width, height, true)
end
image.draw do |pen|
pen.color = black
pen.anti_aliasing = true
pen.dont_blend = false
oldpx = 0.0
oldpy = 0.0
first = true
points do |p|
px = proj.x(p.longitude)
py = proj.y(p.latitude)
pen.line(px, py, oldpx, oldpy) unless first
first = false
oldpy = py
oldpx = px
end
end
image.gif
end
end
TrkPt = Struct.new(:segment, :latitude, :longitude, :altitude, :timestamp) do
def valid?
latitude && longitude && timestamp &&
latitude >= -90 && latitude <= 90 &&
longitude >= -180 && longitude <= 180
end
end
end