app/controllers/swf_controller.rb

   1 class SwfController < ApplicationController
   2         before_filter :check_api_readable
   3
   4 # to log:
   5 # RAILS_DEFAULT_LOGGER.error("Args: #{args[0]}, #{args[1]}, #{args[2]}, #{args[3]}")
   6 # $log.puts Time.new.to_s+','+Time.new.usec.to_s+": started GPS script"
   7 # http://localhost:3000/api/0.4/swf/trackpoints?xmin=-2.32402605810577&xmax=-2.18386309423859&ymin=52.1546608755772&ymax=52.2272777906895&baselong=-2.25325793066437&basey=61.3948537948532&masterscale=5825.4222222222
   8
   9         # ====================================================================
  10         # Public methods
  11
  12         # ---- trackpoints      compile SWF of trackpoints
  13
  14         def trackpoints
  15
  16                 # -     Initialise
  17
  18                 baselong        =params['baselong'].to_f
  19                 basey           =params['basey'].to_f
  20                 masterscale     =params['masterscale'].to_f
  21
  22                 xmin=params['xmin'].to_f;
  23                 xmax=params['xmax'].to_f;
  24                 ymin=params['ymin'].to_f;
  25                 ymax=params['ymax'].to_f;
  26
  27                 # -     Begin movie
  28
  29                 bounds_left  =0
  30                 bounds_right =320*20
  31                 bounds_bottom=0
  32                 bounds_top   =240*20
  33
  34                 m =''
  35                 m+=swfRecord(9,255.chr + 155.chr + 155.chr)                     # Background
  36                 absx=0
  37                 absy=0
  38                 xl=yb= 9999999
  39                 xr=yt=-9999999
  40
  41                 # -     Send SQL for GPS tracks
  42
  43                 b=''
  44                 lasttime=0
  45                 lasttrack=lastfile='-1'
  46
  47                 if params['token']
  48                   user=User.authenticate(:token => params[:token])
  49                   sql="SELECT gps_points.latitude*0.0000001 AS lat,gps_points.longitude*0.0000001 AS lon,gpx_files.id AS fileid,"+
  50                        "      EXTRACT(EPOCH FROM gps_points.timestamp) AS ts, gps_points.trackid AS trackid "+
  51                            " FROM gpx_files,gps_points "+
  52                            "WHERE gpx_files.id=gpx_id "+
  53                            "  AND gpx_files.user_id=#{user.id} "+
  54                            "  AND "+OSM.sql_for_area(ymin,xmin,ymax,xmax,"gps_points.")+
  55                            "  AND (gps_points.timestamp IS NOT NULL) "+
  56                            "ORDER BY fileid DESC,ts "+
  57                            "LIMIT 10000"
  58                   else
  59                         sql="SELECT latitude*0.0000001 AS lat,longitude*0.0000001 AS lon,gpx_id AS fileid,"+
  60                              "      EXTRACT(EPOCH FROM timestamp) AS ts, gps_points.trackid AS trackid "+
  61                                  " FROM gps_points "+
  62                                  "WHERE "+OSM.sql_for_area(ymin,xmin,ymax,xmax,"gps_points.")+
  63                                  "  AND (gps_points.timestamp IS NOT NULL) "+
  64                                  "ORDER BY fileid DESC,ts "+
  65                                  "LIMIT 10000"
  66                 end
  67                 gpslist=ActiveRecord::Base.connection.select_all sql
  68
  69                 # - Draw GPS trace lines
  70
  71                 r=startShape()
  72                 gpslist.each do |row|
  73                         xs=(long2coord(row['lon'].to_f,baselong,masterscale)*20).floor
  74                         ys=(lat2coord(row['lat'].to_f ,basey   ,masterscale)*20).floor
  75                         xl=[xs,xl].min; xr=[xs,xr].max
  76                         yb=[ys,yb].min; yt=[ys,yt].max
  77                         if (row['ts'].to_i-lasttime<180 and row['fileid']==lastfile and row['trackid']==lasttrack and row['ts'].to_i!=lasttime)
  78                                 b+=drawTo(absx,absy,xs,ys)
  79                         else
  80                                 b+=startAndMove(xs,ys,'01')
  81                         end
  82                         absx=xs.floor; absy=ys.floor
  83                         lasttime=row['ts'].to_i
  84                         lastfile=row['fileid']
  85                         lasttrack=row['trackid']
  86                         while b.length>80 do
  87                                 r+=[b.slice!(0...80)].pack("B*")
  88                         end
  89                 end
  90
  91                 #   (Unwayed segments removed)
  92
  93                 # - Write shape
  94
  95                 b+=endShape()
  96                 r+=[b].pack("B*")
  97                 m+=swfRecord(2,packUI16(1) + packRect(xl,xr,yb,yt) + r)
  98                 m+=swfRecord(4,packUI16(1) + packUI16(1))
  99
 100                 # -     Create Flash header and write to browser
 101
 102                 m+=swfRecord(1,'')                                                                      # Show frame
 103                 m+=swfRecord(0,'')                                                                      # End
 104
 105                 m=packRect(bounds_left,bounds_right,bounds_bottom,bounds_top) + 0.chr + 12.chr + packUI16(1) + m
 106                 m='FWS' + 6.chr + packUI32(m.length+8) + m
 107
 108                 render :text => m, :content_type => "application/x-shockwave-flash"
 109         end
 110
 111         private
 112
 113         # =======================================================================
 114         # SWF functions
 115
 116         # -----------------------------------------------------------------------
 117         # Line-drawing
 118
 119         def startShape
 120                 s =0.chr                                                                                # No fill styles
 121                 s+=2.chr                                                                                # Two line styles
 122                 s+=packUI16(0) + 0.chr + 255.chr + 255.chr              # Width 5, RGB #00FFFF
 123                 s+=packUI16(0) + 255.chr + 0.chr + 255.chr              # Width 5, RGB #FF00FF
 124                 s+=34.chr                                                                               # 2 fill, 2 line index bits
 125                 s
 126         end
 127
 128         def endShape
 129                 '000000'
 130         end
 131
 132         def startAndMove(x,y,col)
 133                 d='001001'                                                                              # Line style change, moveTo
 134                 l =[lengthSB(x),lengthSB(y)].max
 135                 d+=sprintf("%05b%0#{l}b%0#{l}b",l,x,y)
 136                 d+=col                                                                                  # Select line style
 137         end
 138
 139         def drawTo(absx,absy,x,y)
 140                 d='11'                                                                                  # TypeFlag, EdgeFlag
 141                 dx=x-absx
 142                 dy=y-absy
 143
 144                 l =[lengthSB(dx),lengthSB(dy)].max
 145                 d+=sprintf("%04b",l-2)
 146                 d+='1'                                                                                  # GeneralLine
 147                 d+=sprintf("%0#{l}b%0#{l}b",dx,dy)
 148         end
 149
 150         # -----------------------------------------------------------------------
 151         # Specific data types
 152
 153         def swfRecord(id,r)
 154                 if r.length>62
 155                         return packUI16((id<<6)+0x3F) + packUI32(r.length) + r
 156                 else
 157                         return packUI16((id<<6)+r.length) + r
 158                 end
 159         end
 160
 161         def packRect(a,b,c,d)
 162                 l=[lengthSB(a),
 163                    lengthSB(b),
 164                    lengthSB(c),
 165                    lengthSB(d)].max
 166                 n=sprintf("%05b%0#{l}b%0#{l}b%0#{l}b%0#{l}b",l,a,b,c,d)
 167                 [n].pack("B*")
 168         end
 169
 170         # -----------------------------------------------------------------------
 171         # Generic pack functions
 172
 173         def packUI16(n)
 174                 [n.floor].pack("v")
 175         end
 176
 177         def packUI32(n)
 178                 [n.floor].pack("V")
 179         end
 180
 181         # Find number of bits required to store arbitrary-length binary
 182
 183         def lengthSB(n)
 184                 Math.frexp(n+ (n==0?1:0) )[1]+1
 185         end
 186
 187         # ====================================================================
 188         # Co-ordinate conversion
 189         # (this is duplicated from amf_controller, should probably share)
 190
 191         def lat2coord(a,basey,masterscale)
 192                 -(lat2y(a)-basey)*masterscale
 193         end
 194
 195         def long2coord(a,baselong,masterscale)
 196                 (a-baselong)*masterscale
 197         end
 198
 199         def lat2y(a)
 200                 180/Math::PI * Math.log(Math.tan(Math::PI/4+a*(Math::PI/180)/2))
 201         end
 202
 203         def sqlescape(a)
 204                 a.gsub("'","''").gsub(92.chr,92.chr+92.chr)
 205         end
 206
 207 end