lib/georuby-ext/proj4.rb
class Proj4::Projection
@@wgs84 = nil
def self.wgs84
@@wgs84 ||= Proj4::Projection.new '+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs'
end
@@goggle = nil
def self.google
@@google ||= Proj4::Projection.new '+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +no_defs'
end
def self.for_srid(srid)
case srid
when 4326
wgs84
when 900913
google
else
begin
Proj4::Projection.new 'init=epsg:'+srid.to_s
rescue
raise "Unsupported srid: #{srid}"
end
end
end
end