app/controllers/swf_controller.rb

   1 class SwfController < ApplicationController
   2         skip_before_filter :verify_authenticity_token
   3         before_filter :check_api_readable
   4
   5 # to log:
   6 # RAILS_DEFAULT_LOGGER.error("Args: #{args[0]}, #{args[1]}, #{args[2]}, #{args[3]}")
   7 # $log.puts Time.new.to_s+','+Time.new.usec.to_s+": started GPS script"
   8 # 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
   9
  10
  11         # ====================================================================
  12         # Public methods
  13
  14         # ---- trackpoints      compile SWF of trackpoints
  15
  16         def trackpoints
  17
  18                 # -     Initialise
  19
  20                 baselong        =params['baselong'].to_f
  21                 basey           =params['basey'].to_f
  22                 masterscale     =params['masterscale'].to_f
  23
  24                 bbox = BoundingBox.new(params['xmin'], params['ymin'],
  25                                        params['xmax'], params['ymax'])
  26                 start=params['start'].to_i;
  27
  28                 # -     Begin movie
  29
  30                 bounds_left  =0
  31                 bounds_right =320*20
  32                 bounds_bottom=0
  33                 bounds_top   =240*20
  34
  35                 m =''
  36                 m+=swfRecord(9,255.chr + 155.chr + 155.chr)                     # Background
  37                 absx=0
  38                 absy=0
  39                 xl=yb= 9999999
  40                 xr=yt=-9999999
  41
  42                 # -     Send SQL for GPS tracks
  43
  44                 b=''
  45                 lasttime=0
  46                 lasttrack=lastfile='-1'
  47
  48                 if params['token']
  49                   user=User.authenticate(:token => params[:token])
  50                   sql="SELECT gps_points.latitude*0.0000001 AS lat,gps_points.longitude*0.0000001 AS lon,gpx_files.id AS fileid,"+
  51                        "      EXTRACT(EPOCH FROM gps_points.timestamp) AS ts, gps_points.trackid AS trackid "+
  52                            " FROM gpx_files,gps_points "+
  53                            "WHERE gpx_files.id=gpx_id "+
  54                            "  AND gpx_files.user_id=#{user.id} "+
  55                            "  AND "+OSM.sql_for_area(bbox,"gps_points.")+
  56                            "  AND (gps_points.timestamp IS NOT NULL) "+
  57                            "ORDER BY fileid DESC,ts "+
  58                            "LIMIT 10000 OFFSET #{start}"
  59                   else
  60                         sql="SELECT latitude*0.0000001 AS lat,longitude*0.0000001 AS lon,gpx_id AS fileid,"+
  61                              "      EXTRACT(EPOCH FROM timestamp) AS ts, gps_points.trackid AS trackid "+
  62                                  " FROM gps_points "+
  63                                  "WHERE "+OSM.sql_for_area(bbox,"gps_points.")+
  64                                  "  AND (gps_points.timestamp IS NOT NULL) "+
  65                                  "ORDER BY fileid DESC,ts "+
  66                                  "LIMIT 10000 OFFSET #{start}"
  67                 end
  68                 gpslist=ActiveRecord::Base.connection.select_all sql
  69
  70                 # - Draw GPS trace lines
  71
  72                 r=startShape()
  73                 gpslist.each do |row|
  74                         xs=(long2coord(row['lon'].to_f,baselong,masterscale)*20).floor
  75                         ys=(lat2coord(row['lat'].to_f ,basey   ,masterscale)*20).floor
  76                         xl=[xs,xl].min; xr=[xs,xr].max
  77                         yb=[ys,yb].min; yt=[ys,yt].max
  78                         if row['ts'].to_i-lasttime>180 or row['fileid']!=lastfile or row['trackid']!=lasttrack #or row['ts'].to_i==lasttime
  79                           b+=startAndMove(xs,ys,'01')
  80                           absx=xs.floor; absy=ys.floor
  81       end
  82                   b+=drawTo(absx,absy,xs,ys)
  83                         absx=xs.floor; absy=ys.floor
  84                         lasttime=row['ts'].to_i
  85                         lastfile=row['fileid']
  86                         lasttrack=row['trackid']
  87                         while b.length>80 do
  88                                 r+=[b.slice!(0...80)].pack("B*")
  89                         end
  90                 end
  91
  92                 #   (Unwayed segments removed)
  93
  94                 # - Write shape
  95
  96                 b+=endShape()
  97                 r+=[b].pack("B*")
  98                 m+=swfRecord(2,packUI16(1) + packRect(xl,xr,yb,yt) + r)
  99                 m+=swfRecord(4,packUI16(1) + packUI16(1))
 100
 101                 # -     Create Flash header and write to browser
 102
 103                 m+=swfRecord(1,'')                                                                      # Show frame
 104                 m+=swfRecord(0,'')                                                                      # End
 105
 106                 m=packRect(bounds_left,bounds_right,bounds_bottom,bounds_top) + 0.chr + 12.chr + packUI16(1) + m
 107                 m='FWS' + 6.chr + packUI32(m.length+8) + m
 108
 109                 render :text => m, :content_type => "application/x-shockwave-flash"
 110         end
 111
 112         private
 113
 114         # =======================================================================
 115         # SWF functions
 116
 117         # -----------------------------------------------------------------------
 118         # Line-drawing
 119
 120         def startShape
 121                 s =0.chr                                                                                # No fill styles
 122                 s+=2.chr                                                                                # Two line styles
 123                 s+=packUI16(0) + 0.chr + 255.chr + 255.chr              # Width 5, RGB #00FFFF
 124                 s+=packUI16(0) + 255.chr + 0.chr + 255.chr              # Width 5, RGB #FF00FF
 125                 s+=34.chr                                                                               # 2 fill, 2 line index bits
 126                 s
 127         end
 128
 129         def endShape
 130                 '000000'
 131         end
 132
 133         def startAndMove(x,y,col)
 134                 d='001001'                                                                              # Line style change, moveTo
 135                 l =[lengthSB(x),lengthSB(y)].max
 136                 d+=sprintf("%05b%0#{l}b%0#{l}b",l,x,y)
 137                 d+=col                                                                                  # Select line style
 138         end
 139
 140         def drawTo(absx,absy,x,y)
 141                 dx=x-absx
 142                 dy=y-absy
 143
 144     # Split the line up if there's anything>16383, because
 145     # that would overflow the 4 bits allowed for length
 146     mstep=[dx.abs/16383,dy.abs/16383,1].max.ceil
 147     xstep=dx/mstep
 148     ystep=dy/mstep
 149     d=''
 150     for i in (1..mstep)
 151       d+=drawSection(x,y,x+xstep,y+ystep)
 152       x+=xstep
 153       y+=ystep
 154     end
 155     d
 156         end
 157
 158         def drawSection(x1,y1,x2,y2)
 159                 d='11'                                                                                  # TypeFlag, EdgeFlag
 160           dx=x2-x1
 161           dy=y2-y1
 162                 l =[lengthSB(dx),lengthSB(dy)].max
 163                 d+=sprintf("%04b",l-2)
 164                 d+='1'                                                                                  # GeneralLine
 165                 d+=sprintf("%0#{l}b%0#{l}b",dx,dy)
 166   end
 167
 168         # -----------------------------------------------------------------------
 169         # Specific data types
 170
 171   # SWF data block type
 172
 173         def swfRecord(id,r)
 174                 if r.length>62
 175       # Long header: tag id, 0x3F, length
 176                         return packUI16((id<<6)+0x3F) + packUI32(r.length) + r
 177                 else
 178       # Short header: tag id, length
 179                         return packUI16((id<<6)+r.length) + r
 180                 end
 181         end
 182
 183   # SWF RECT type
 184
 185         def packRect(a,b,c,d)
 186                 l=[lengthSB(a),
 187                    lengthSB(b),
 188                    lengthSB(c),
 189                    lengthSB(d)].max
 190     # create binary string (00111001 etc.) - 5-byte length, then bbox
 191                 n=sprintf("%05b%0#{l}b%0#{l}b%0#{l}b%0#{l}b",l,a,b,c,d)
 192     # pack into byte string
 193                 [n].pack("B*")
 194         end
 195
 196         # -----------------------------------------------------------------------
 197         # Generic pack functions
 198
 199         def packUI16(n)
 200                 [n.floor].pack("v")
 201         end
 202
 203         def packUI32(n)
 204                 [n.floor].pack("V")
 205         end
 206
 207         # Find number of bits required to store arbitrary-length binary
 208
 209         def lengthSB(n)
 210                 Math.frexp(n+ (n==0?1:0) )[1]+1
 211         end
 212
 213         # ====================================================================
 214         # Co-ordinate conversion
 215         # (this is duplicated from amf_controller, should probably share)
 216
 217         def lat2coord(a,basey,masterscale)
 218                 -(lat2y(a)-basey)*masterscale
 219         end
 220
 221         def long2coord(a,baselong,masterscale)
 222                 (a-baselong)*masterscale
 223         end
 224
 225         def lat2y(a)
 226                 180/Math::PI * Math.log(Math.tan(Math::PI/4+a*(Math::PI/180)/2))
 227         end
 228
 229         def sqlescape(a)
 230                 a.gsub("'","''").gsub(92.chr,92.chr+92.chr)
 231         end
 232
 233 end