class AmfController < ApplicationController require 'stringio' # to log: # RAILS_DEFAULT_LOGGER.error("Args: #{args[0]}, #{args[1]}, #{args[2]}, #{args[3]}") # ==================================================================== # Main AMF handler # ---- talk process AMF request def talk req=StringIO.new(request.raw_post) # Get POST data as request req.read(2) # Skip version indicator and client ID results={} # Results of each body # ------------- # Parse request headers=getint(req) # Read number of headers headers.times do # Read each header name=getstring(req) # | req.getc # | skip boolean value=getvalue(req) # | header["name"]=value # | end bodies=getint(req) # Read number of bodies bodies.times do # Read each body message=getstring(req) # | get message name index=getstring(req) # | get index in response sequence bytes=getlong(req) # | get total size in bytes args=getvalue(req) # | get response (probably an array) case message when 'getpresets'; results[index]=putdata(index,getpresets) when 'whichways'; results[index]=putdata(index,whichways(args)) when 'getway'; results[index]=putdata(index,getway(args)) when 'putway'; results[index]=putdata(index,putway(args)) when 'deleteway'; results[index]=putdata(index,deleteway(args)) end end # ------------------ # Write out response response.headers["Content-Type"]="application/x-amf" a,b=results.length.divmod(256) ans=0.chr+0.chr+0.chr+0.chr+a.chr+b.chr results.each do |k,v| ans+=v end render :text => ans end private # ==================================================================== # Remote calls # ----- getpresets # return presets,presetmenus and presetnames arrays def getpresets presets={} presetmenus={}; presetmenus['point']=[]; presetmenus['way']=[] presetnames={}; presetnames['point']={}; presetnames['way']={} presettype='' presetcategory='' # File.open("config/potlatch/presets.txt") do |file| # Temporary patch to get around filepath problem # To remove this patch and make the code nice again: # 1. uncomment above line # 2. fix the path in the above line # 3. delete this here document, and the following line (StringIO....) txt=<<-EOF way/road motorway: highway=motorway,ref=(type road number) trunk road: highway=trunk,ref=(type road number),name=(type road name) primary road: highway=primary,ref=(type road number),name=(type road name) secondary road: highway=secondary,ref=(type road number),name=(type road name) residential road: highway=residential,name=(type road name) unclassified road: highway=unclassified,name=(type road name) way/footway footpath: highway=footway,foot=yes bridleway: highway=bridleway,foot=yes,horse=yes,bicycle=yes byway: highway=byway,foot=yes,horse=yes,bicycle=yes,motorcar=yes permissive path: highway=footway,foot=permissive way/cycleway cycle lane: highway=cycleway,cycleway=lane,ncn_ref= cycle track: highway=cycleway,cycleway=track,ncn_ref= cycle lane (NCN): highway=cycleway,cycleway=lane,name=(type name here),ncn_ref=(type route number) cycle track (NCN): highway=cycleway,cycleway=track,name=(type name here),ncn_ref=(type route number) way/waterway canal: waterway=canal,name=(type name here) navigable river: waterway=river,boat=yes,name=(type name here) navigable drain: waterway=drain,boat=yes,name=(type name here) derelict canal: waterway=derelict_canal,name=(type name here) unnavigable river: waterway=river,boat=no,name=(type name here) unnavigable drain: waterway=drain,boat=no,name=(type name here) way/railway railway: railway=rail tramway: railway=tram light railway: railway=light_rail preserved railway: railway=preserved disused railway tracks: railway=disused course of old railway: railway=abandoned point/road mini roundabout: highway=mini_roundabout traffic lights: highway=traffic_signals point/footway bridge: highway=bridge gate: highway=gate stile: highway=stile cattle grid: highway=cattle_grid point/cycleway gate: highway=gate point/waterway lock gate: waterway=lock_gate weir: waterway=weir aqueduct: waterway=aqueduct winding hole: waterway=turning_point mooring: waterway=mooring point/railway station: railway=station viaduct: railway=viaduct level crossing: railway=crossing EOF StringIO.open(txt) do |file| file.each_line {|line| t=line.chomp if (t=~/(\w+)\/(\w+)/) then presettype=$1 presetcategory=$2 presetmenus[presettype].push(presetcategory) presetnames[presettype][presetcategory]=["(no preset)"] elsif (t=~/^(.+):\s?(.+)$/) then pre=$1; kv=$2 presetnames[presettype][presetcategory].push(pre) presets[pre]={} kv.split(',').each {|a| if (a=~/^(.+)=(.*)$/) then presets[pre][$1]=$2 end } end } end return [presets,presetmenus,presetnames] end # ----- whichways(left,bottom,right,top) # return array of ways in current bounding box # at present, instead of using correct (=more complex) SQL to find # corner-crossing ways, it simply enlarges the bounding box by +/- 0.01 def whichways(args) waylist=WaySegment.find_by_sql("SELECT DISTINCT current_way_segments.id AS wayid"+ " FROM current_way_segments,current_segments,current_nodes,current_ways "+ " WHERE segment_id=current_segments.id "+ " AND current_segments.visible=1 "+ " AND node_a=current_nodes.id "+ " AND current_ways.id=current_way_segments.id "+ " AND current_ways.visible=1 "+ " AND (latitude BETWEEN "+(args[1].to_f-0.01).to_s+" AND "+(args[3].to_f+0.01).to_s+") "+ " AND (longitude BETWEEN "+(args[0].to_f-0.01).to_s+" AND "+(args[2].to_f+0.01).to_s+")") ways = waylist.collect {|a| a.wayid.to_i } # get an array of way id's pointlist =ActiveRecord::Base.connection.select_all("SELECT current_nodes.id,current_nodes.tags "+ " FROM current_nodes "+ " LEFT OUTER JOIN current_segments cs1 ON cs1.node_a=current_nodes.id "+ " LEFT OUTER JOIN current_segments cs2 ON cs2.node_b=current_nodes.id "+ " WHERE (latitude BETWEEN "+(args[1].to_f-0.01).to_s+" AND "+(args[3].to_f+0.01).to_s+") "+ " AND (longitude BETWEEN "+(args[0].to_f-0.01).to_s+" AND "+(args[2].to_f-0.01).to_s+") "+ " AND cs1.id IS NULL AND cs2.id IS NULL "+ " AND current_nodes.visible=1") points = pointlist.collect {|a| [a['id'],tag2array(a['tags'])] } # get a list of node ids and their tags return [ways,points] end # ----- getway (objectname, way, baselong, basey, masterscale) # returns objectname, array of co-ordinates, attributes, # xmin,xmax,ymin,ymax def getway(args) objname,wayid,baselong,basey,masterscale=args wayid = wayid.to_i points = [] lastid = -1 xmin = ymin = 999999 xmax = ymax = -999999 readwayquery(wayid).each {|row| xs1=long2coord(row['long1'].to_f,baselong,masterscale); ys1=lat2coord(row['lat1'].to_f,basey,masterscale) xs2=long2coord(row['long2'].to_f,baselong,masterscale); ys2=lat2coord(row['lat2'].to_f,basey,masterscale) points << [xs1,ys1,row['id1'].to_i,0,tag2array(row['tags1']),0] if (row['id1'].to_i!=lastid) lastid = row['id2'].to_i points << [xs2,ys2,row['id2'].to_i,1,tag2array(row['tags2']),row['segment_id'].to_i] xmin = [xmin,row['long1'].to_f,row['long2'].to_f].min xmax = [xmax,row['long1'].to_f,row['long2'].to_f].max ymin = [ymin,row['lat1'].to_f,row['lat2'].to_f].min ymax = [ymax,row['lat1'].to_f,row['lat2'].to_f].max } attributes={} attrlist=ActiveRecord::Base.connection.select_all "SELECT k,v FROM current_way_tags WHERE id=#{wayid}" attrlist.each {|a| attributes[a['k']]=a['v'] } [objname,points,attributes,xmin,xmax,ymin,ymax] end # ----- putway (user token, way, array of co-ordinates, array of attributes, # baselong, basey, masterscale) # returns current way ID, new way ID, hash of renumbered nodes, # xmin,xmax,ymin,ymax def putway(args) usertoken,originalway,points,attributes,baselong,basey,masterscale=args uid=getuserid(usertoken) return if !uid db_uqs='uniq'+uid.to_s+originalway.to_i.abs.to_s+Time.new.to_i.to_s # temp uniquesegments table name, typically 51 chars db_uqn='unin'+uid.to_s+originalway.to_i.abs.to_s+Time.new.to_i.to_s # temp uniquenodes table name, typically 51 chars db_now='@now'+uid.to_s+originalway.to_i.abs.to_s+Time.new.to_i.to_s # 'now' variable name, typically 51 chars ActiveRecord::Base.connection.execute("SET #{db_now}=NOW()") originalway=originalway.to_i # -- 3. read original way into memory xc={}; yc={}; tagc={}; seg={} if originalway>0 way=originalway readwayquery(way).each { |row| id1=row['id1'].to_i; xc[id1]=row['long1'].to_f; yc[id1]=row['lat1'].to_f; tagc[id1]=row['tags1'] id2=row['id2'].to_i; xc[id2]=row['long2'].to_f; yc[id2]=row['lat2'].to_f; tagc[id2]=row['tags2'] seg[row['segment_id'].to_i]=id1.to_s+'-'+id2.to_s } ActiveRecord::Base.connection.update("UPDATE current_ways SET timestamp=#{db_now},user_id=#{uid},visible=1 WHERE id=#{way}") else way=ActiveRecord::Base.connection.insert("INSERT INTO current_ways (user_id,timestamp,visible) VALUES (#{uid},#{db_now},1)") end # -- 4. get version by inserting new row into ways version=ActiveRecord::Base.connection.insert("INSERT INTO ways (id,user_id,timestamp,visible) VALUES (#{way},#{uid},#{db_now},1)") # -- 5. compare nodes and update xmin,xmax,ymin,ymax xmin = ymin = 999999 xmax = ymax = -999999 insertsql = nodelist = '' renumberednodes={} points.each_index do |i| xs=coord2long(points[i][0],masterscale,baselong) ys=coord2lat(points[i][1],masterscale,basey) xmin=[xs,xmin].min; xmax=[xs,xmax].max ymin=[ys,ymin].min; ymax=[ys,ymax].max node=points[i][2].to_i tagstr=array2tag(points[i][4]) tagsql="'"+sqlescape(tagstr)+"'" # compare node if node<0 # new node - create newnode=ActiveRecord::Base.connection.insert("INSERT INTO current_nodes ( latitude,longitude,timestamp,user_id,visible,tags) VALUES ( #{ys},#{xs},#{db_now},#{uid},1,#{tagsql})") ActiveRecord::Base.connection.insert("INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible,tags) VALUES (#{newnode},#{ys},#{xs},#{db_now},#{uid},1,#{tagsql})") points[i][2]=newnode renumberednodes[node.to_s]=newnode.to_s elsif xc.has_key?(node) # old node from original way - update if (xs!=xc[node] or (ys/0.0000001).round!=(yc[node]/0.0000001).round or tagstr!=tagc[node]) ActiveRecord::Base.connection.insert("INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible,tags) VALUES (#{node},#{ys},#{xs},#{db_now},#{uid},1,#{tagsql})") ActiveRecord::Base.connection.update("UPDATE current_nodes SET latitude=#{ys},longitude=#{xs},timestamp=#{db_now},user_id=#{uid},tags=#{tagsql},visible=1 WHERE id=#{node}") else if (nodelist!='') then nodelist+=',' end; nodelist+=node.to_s end else # old node, created in another way and now added to this way if (nodelist!='') then nodelist+=',' end; nodelist+=node.to_s end end if nodelist!='' then ActiveRecord::Base.connection.update("UPDATE current_nodes SET timestamp=#{db_now},user_id=#{uid},visible=1 WHERE id IN (#{nodelist})") end # -- 6.i compare segments numberedsegments={} seglist='' for i in (0..(points.length-2)) if (points[i+1][3].to_i==0) then next end segid=points[i+1][5].to_i from =points[i ][2].to_i to =points[i+1][2].to_i if seg.has_key?(segid) if seg[segid]=="#{from}-#{to}" then if (seglist!='') then seglist+=',' end; seglist+=segid.to_s next end end segid=ActiveRecord::Base.connection.insert("INSERT INTO current_segments ( node_a,node_b,timestamp,user_id,visible,tags) VALUES ( #{from},#{to},#{db_now},#{uid},1,'')") ActiveRecord::Base.connection.insert("INSERT INTO segments (id,node_a,node_b,timestamp,user_id,visible,tags) VALUES (#{segid},#{from},#{to},#{db_now},#{uid},1,'')") points[i+1][5]=segid numberedsegments[(i+1).to_s]=segid.to_s end # numberedsegments.each{|a,b| RAILS_DEFAULT_LOGGER.error("Sending back: seg no. #{a} -> id #{b}") } if seglist!='' then ActiveRecord::Base.connection.update("UPDATE current_segments SET timestamp=#{db_now},user_id=#{uid},visible=1 WHERE id IN (#{seglist})") end # -- 6.ii insert new way segments createuniquesegments(way,db_uqs) # delete segments from uniquesegments (and not in modified way) sql=<<-EOF INSERT INTO segments (id,node_a,node_b,timestamp,user_id,visible) SELECT DISTINCT segment_id,node_a,node_b,#{db_now},#{uid},0 FROM current_segments AS cs, #{db_uqs} AS us WHERE cs.id=us.segment_id AND cs.visible=1 AND (cs.timestamp!=#{db_now} OR cs.user_id!=#{uid}) EOF ActiveRecord::Base.connection.insert(sql) sql=<<-EOF UPDATE current_segments AS cs, #{db_uqs} AS us SET cs.timestamp=#{db_now},cs.visible=0,cs.user_id=#{uid} WHERE cs.id=us.segment_id AND cs.visible=1 AND (cs.timestamp!=#{db_now} OR cs.user_id!=#{uid}) EOF ActiveRecord::Base.connection.update(sql) # delete nodes not in modified way or any other segments createuniquenodes(db_uqs,db_uqn) sql=<<-EOF INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible) SELECT DISTINCT cn.id,cn.latitude,cn.longitude,#{db_now},#{uid},0 FROM current_nodes AS cn,#{db_uqn} WHERE cn.id=node_id EOF ActiveRecord::Base.connection.insert(sql) sql=<<-EOF UPDATE current_nodes AS cn, #{db_uqn} SET cn.timestamp=#{db_now},cn.visible=0,cn.user_id=#{uid} WHERE cn.id=node_id EOF ActiveRecord::Base.connection.update(sql) ActiveRecord::Base.connection.execute("DROP TABLE #{db_uqs}") ActiveRecord::Base.connection.execute("DROP TABLE #{db_uqn}") # insert new version of route into way_segments insertsql ='' currentsql='' sequence =1 for i in (0..(points.length-2)) if (points[i+1][3].to_i==0) then next end if insertsql !='' then insertsql +=',' end if currentsql!='' then currentsql+=',' end insertsql +="(#{way},#{points[i+1][5]},#{version})" currentsql+="(#{way},#{points[i+1][5]},#{sequence})" sequence +=1 end ActiveRecord::Base.connection.execute("DELETE FROM current_way_segments WHERE id=#{way}"); ActiveRecord::Base.connection.insert("INSERT INTO way_segments (id,segment_id,version ) VALUES #{insertsql}"); ActiveRecord::Base.connection.insert("INSERT INTO current_way_segments (id,segment_id,sequence_id) VALUES #{currentsql}"); # -- 7. insert new way tags insertsql ='' currentsql='' attributes.each do |k,v| if v=='' then next end if v[0,6]=='(type ' then next end if insertsql !='' then insertsql +=',' end if currentsql!='' then currentsql+=',' end insertsql +="(#{way},'"+sqlescape(k)+"','"+sqlescape(v)+"',version)" currentsql+="(#{way},'"+sqlescape(k)+"','"+sqlescape(v)+"')" end ActiveRecord::Base.connection.execute("DELETE FROM current_way_tags WHERE id=#{way}") if (insertsql !='') then ActiveRecord::Base.connection.insert("INSERT INTO way_tags (id,k,v,version) VALUES #{insertsql}" ) end if (currentsql!='') then ActiveRecord::Base.connection.insert("INSERT INTO current_way_tags (id,k,v) VALUES #{currentsql}") end [originalway,way,renumberednodes,numberedsegments,xmin,xmax,ymin,ymax] end # ----- deleteway (user token, way) # returns way ID only def deleteway(args) usertoken,way=args uid=getuserid(usertoken); if !uid then return end way=way.to_i db_uqs='uniq'+uid.to_s+way.to_i.abs.to_s+Time.new.to_i.to_s # temp uniquesegments table name, typically 51 chars db_uqn='unin'+uid.to_s+way.to_i.abs.to_s+Time.new.to_i.to_s # temp uniquenodes table name, typically 51 chars db_now='@now'+uid.to_s+way.to_i.abs.to_s+Time.new.to_i.to_s # 'now' variable name, typically 51 chars ActiveRecord::Base.connection.execute("SET #{db_now}=NOW()") createuniquesegments(way,db_uqs) # - delete any otherwise unused segments sql=<<-EOF INSERT INTO segments (id,node_a,node_b,timestamp,user_id,visible) SELECT DISTINCT segment_id,node_a,node_b,#{db_now},#{uid},0 FROM current_segments AS cs, #{db_uqs} AS us WHERE cs.id=us.segment_id EOF ActiveRecord::Base.connection.insert(sql) sql=<<-EOF UPDATE current_segments AS cs, #{db_uqs} AS us SET cs.timestamp=#{db_now},cs.visible=0,cs.user_id=#{uid} WHERE cs.id=us.segment_id EOF ActiveRecord::Base.connection.update(sql) # - delete any unused nodes createuniquenodes(db_uqs,db_uqn) sql=<<-EOF INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible) SELECT DISTINCT cn.id,cn.latitude,cn.longitude,#{db_now},#{uid},0 FROM current_nodes AS cn,#{db_uqn} WHERE cn.id=node_id EOF ActiveRecord::Base.connection.insert(sql) sql=<<-EOF UPDATE current_nodes AS cn, #{db_uqn} SET cn.timestamp=#{db_now},cn.visible=0,cn.user_id=#{uid} WHERE cn.id=node_id EOF ActiveRecord::Base.connection.update(sql) ActiveRecord::Base.connection.execute("DROP TABLE #{db_uqs}") ActiveRecord::Base.connection.execute("DROP TABLE #{db_uqn}") # - delete way ActiveRecord::Base.connection.insert("INSERT INTO ways (id,user_id,timestamp,visible) VALUES (#{way},#{uid},#{db_now},0)") ActiveRecord::Base.connection.update("UPDATE current_ways SET user_id=#{uid},timestamp=#{db_now},visible=0 WHERE id=#{way}") ActiveRecord::Base.connection.execute("DELETE FROM current_way_segments WHERE id=#{way}") ActiveRecord::Base.connection.execute("DELETE FROM current_way_tags WHERE id=#{way}") way end # ==================================================================== # Support functions for remote calls def readwayquery(id) ActiveRecord::Base.connection.select_all "SELECT n1.latitude AS lat1,n1.longitude AS long1,n1.id AS id1,n1.tags as tags1, "+ " n2.latitude AS lat2,n2.longitude AS long2,n2.id AS id2,n2.tags as tags2,segment_id "+ " FROM current_way_segments,current_segments,current_nodes AS n1,current_nodes AS n2 "+ " WHERE current_way_segments.id=#{id} "+ " AND segment_id=current_segments.id "+ " AND current_segments.visible=1 "+ " AND n1.id=node_a and n2.id=node_b "+ " AND n1.visible=1 AND n2.visible=1 "+ " ORDER BY sequence_id" end def createuniquesegments(way,uqs_name) # Finds segments which appear in this way and no other sql=<<-EOF CREATE TEMPORARY TABLE #{uqs_name} SELECT a.segment_id FROM (SELECT DISTINCT segment_id FROM current_way_segments WHERE id = #{way}) a LEFT JOIN current_way_segments b ON b.segment_id = a.segment_id AND b.id != #{way} WHERE b.segment_id IS NULL EOF ActiveRecord::Base.connection.execute(sql) end def createuniquenodes(uqs_name,uqn_name) # Finds nodes which appear in uniquesegments but no other segments sql=<<-EOF CREATE TEMPORARY TABLE #{uqn_name} SELECT DISTINCT node_id FROM (SELECT cn.id AS node_id FROM current_nodes AS cn, current_segments AS cs, #{uqs_name} AS us WHERE cs.id=us.segment_id AND (cn.id=cs.node_a OR cn.id=cs.node_b)) AS n LEFT JOIN current_segments AS cs2 ON node_id=cs2.node_a AND cs2.visible=1 LEFT JOIN current_segments AS cs3 ON node_id=cs3.node_b AND cs3.visible=1 WHERE cs2.node_a IS NULL AND cs3.node_b IS NULL EOF ActiveRecord::Base.connection.execute(sql) end def sqlescape(a) a.gsub("'","''").gsub(92.chr,92.chr+92.chr) end def tag2array(a) tags={} a.gsub(';;;','#%').split(';').each do |b| b.gsub!('#%',';;;') b.gsub!('===','#%') k,v=b.split('=') if k.nil? then k='' end if v.nil? then v='' end tags[k.gsub('#%','=')]=v.gsub('#%','=') end tags end def array2tag(a) str='' a.each do |k,v| if v=='' then next end if v[0,6]=='(type ' then next end if str!='' then str+=';' end str+=k.gsub(';',';;;').gsub('=','===')+'='+v.gsub(';',';;;').gsub('=','===') end str end def getuserid(token) token=sqlescape(token) if (token=~/^(.+)\+(.+)$/) then return ActiveRecord::Base.connection.select_value("SELECT id FROM users WHERE active=1 AND email='#{$1}' AND pass_crypt=MD5('#{$2}')") else return ActiveRecord::Base.connection.select_value("SELECT id FROM users WHERE active=1 AND token='#{token}'") end end # ==================================================================== # AMF read subroutines # ----- getint return two-byte integer # ----- getlong return four-byte long # ----- getstring return string with two-byte length # ----- getdouble return eight-byte double-precision float # ----- getobject return object/hash # ----- getarray return numeric array def getint(s) s.getc*256+s.getc end def getlong(s) ((s.getc*256+s.getc)*256+s.getc)*256+s.getc end def getstring(s) len=s.getc*256+s.getc s.read(len) end def getdouble(s) a=s.read(8).unpack('G') # G big-endian, E little-endian a[0] end def getarray(s) len=getlong(s) arr=[] for i in (0..len-1) arr[i]=getvalue(s) end arr end def getobject(s) arr={} while (key=getstring(s)) if (key=='') then break end arr[key]=getvalue(s) end s.getc # skip the 9 'end of object' value arr end # ----- getvalue parse and get value def getvalue(s) case s.getc when 0; return getdouble(s) # number when 1; return s.getc # boolean when 2; return getstring(s) # string when 3; return getobject(s) # object/hash when 5; return nil # null when 6; return nil # undefined when 8; s.read(4) # mixedArray return getobject(s) # | when 10;return getarray(s) # array else; return nil # error end end # ==================================================================== # AMF write subroutines # ----- putdata envelope data into AMF writeable form # ----- encodevalue pack variables as AMF def putdata(index,n) d =encodestring(index+"/onResult") d+=encodestring("null") d+=[-1].pack("N") d+=encodevalue(n) end def encodevalue(n) case n.class.to_s when 'Array' a=10.chr+encodelong(n.length) n.each do |b| a+=encodevalue(b) end a when 'Hash' a=3.chr n.each do |k,v| a+=encodestring(k)+encodevalue(v) end a+0.chr+0.chr+9.chr when 'String' 2.chr+encodestring(n) when 'Bignum','Fixnum','Float' 0.chr+encodedouble(n) when 'NilClass' 5.chr else RAILS_DEFAULT_LOGGER.error("Unexpected Ruby type for AMF conversion: "+n.class.to_s) end end # ----- encodestring encode string with two-byte length # ----- encodedouble encode number as eight-byte double precision float # ----- encodelong encode number as four-byte long def encodestring(n) a,b=n.size.divmod(256) a.chr+b.chr+n end def encodedouble(n) [n].pack('G') end def encodelong(n) [n].pack('N') end # ==================================================================== # Co-ordinate conversion def lat2coord(a,basey,masterscale) -(lat2y(a)-basey)*masterscale+250 end def long2coord(a,baselong,masterscale) (a-baselong)*masterscale+350 end def lat2y(a) 180/Math::PI * Math.log(Math.tan(Math::PI/4+a*(Math::PI/180)/2)) end def coord2lat(a,masterscale,basey) y2lat((a-250)/-masterscale+basey) end def coord2long(a,masterscale,baselong) (a-350)/masterscale+baselong end def y2lat(a) 180/Math::PI * (2*Math.atan(Math.exp(a*Math::PI/180))-Math::PI/2) end end