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                 xmin=params['xmin'].to_f;
  25                 xmax=params['xmax'].to_f;
  26                 ymin=params['ymin'].to_f;
  27                 ymax=params['ymax'].to_f;
  28                 start=params['start'].to_i;
  29
  30                 # -     Begin movie
  31
  32                 bounds_left  =0
  33                 bounds_right =320*20
  34                 bounds_bottom=0
  35                 bounds_top   =240*20
  36
  37                 m =''
  38                 m+=swfRecord(9,255.chr + 155.chr + 155.chr)                     # Background
  39                 absx=0
  40                 absy=0
  41                 xl=yb= 9999999
  42                 xr=yt=-9999999
  43
  44                 # -     Send SQL for GPS tracks
  45
  46                 b=''
  47                 lasttime=0
  48                 lasttrack=lastfile='-1'
  49
  50                 if params['token']
  51                   user=User.authenticate(:token => params[:token])
  52                   sql="SELECT gps_points.latitude*0.0000001 AS lat,gps_points.longitude*0.0000001 AS lon,gpx_files.id AS fileid,"+
  53                        "      EXTRACT(EPOCH FROM gps_points.timestamp) AS ts, gps_points.trackid AS trackid "+
  54                            " FROM gpx_files,gps_points "+
  55                            "WHERE gpx_files.id=gpx_id "+
  56                            "  AND gpx_files.user_id=#{user.id} "+
  57                            "  AND "+OSM.sql_for_area(ymin,xmin,ymax,xmax,"gps_points.")+
  58                            "  AND (gps_points.timestamp IS NOT NULL) "+
  59                            "ORDER BY fileid DESC,ts "+
  60                            "LIMIT 10000 OFFSET #{start}"
  61                   else
  62                         sql="SELECT latitude*0.0000001 AS lat,longitude*0.0000001 AS lon,gpx_id AS fileid,"+
  63                              "      EXTRACT(EPOCH FROM timestamp) AS ts, gps_points.trackid AS trackid "+
  64                                  " FROM gps_points "+
  65                                  "WHERE "+OSM.sql_for_area(ymin,xmin,ymax,xmax,"gps_points.")+
  66                                  "  AND (gps_points.timestamp IS NOT NULL) "+
  67                                  "ORDER BY fileid DESC,ts "+
  68                                  "LIMIT 10000 OFFSET #{start}"
  69                 end
  70                 gpslist=ActiveRecord::Base.connection.select_all sql
  71
  72                 # - Draw GPS trace lines
  73
  74                 r=startShape()
  75                 gpslist.each do |row|
  76                         xs=(long2coord(row['lon'].to_f,baselong,masterscale)*20).floor
  77                         ys=(lat2coord(row['lat'].to_f ,basey   ,masterscale)*20).floor
  78                         xl=[xs,xl].min; xr=[xs,xr].max
  79                         yb=[ys,yb].min; yt=[ys,yt].max
  80                         if row['ts'].to_i-lasttime>180 or row['fileid']!=lastfile or row['trackid']!=lasttrack #or row['ts'].to_i==lasttime
  81                           b+=startAndMove(xs,ys,'01')
  82                           absx=xs.floor; absy=ys.floor
  83       end
  84                   b+=drawTo(absx,absy,xs,ys)
  85                         absx=xs.floor; absy=ys.floor
  86                         lasttime=row['ts'].to_i
  87                         lastfile=row['fileid']
  88                         lasttrack=row['trackid']
  89                         while b.length>80 do
  90                                 r+=[b.slice!(0...80)].pack("B*")
  91                         end
  92                 end
  93
  94                 #   (Unwayed segments removed)
  95
  96                 # - Write shape
  97
  98                 b+=endShape()
  99                 r+=[b].pack("B*")
 100                 m+=swfRecord(2,packUI16(1) + packRect(xl,xr,yb,yt) + r)
 101                 m+=swfRecord(4,packUI16(1) + packUI16(1))
 102
 103                 # -     Create Flash header and write to browser
 104
 105                 m+=swfRecord(1,'')                                                                      # Show frame
 106                 m+=swfRecord(0,'')                                                                      # End
 107
 108                 m=packRect(bounds_left,bounds_right,bounds_bottom,bounds_top) + 0.chr + 12.chr + packUI16(1) + m
 109                 m='FWS' + 6.chr + packUI32(m.length+8) + m
 110
 111                 render :text => m, :content_type => "application/x-shockwave-flash"
 112         end
 113
 114         private
 115
 116         # =======================================================================
 117         # SWF functions
 118
 119         # -----------------------------------------------------------------------
 120         # Line-drawing
 121
 122         def startShape
 123                 s =0.chr                                                                                # No fill styles
 124                 s+=2.chr                                                                                # Two line styles
 125                 s+=packUI16(0) + 0.chr + 255.chr + 255.chr              # Width 5, RGB #00FFFF
 126                 s+=packUI16(0) + 255.chr + 0.chr + 255.chr              # Width 5, RGB #FF00FF
 127                 s+=34.chr                                                                               # 2 fill, 2 line index bits
 128                 s
 129         end
 130
 131         def endShape
 132                 '000000'
 133         end
 134
 135         def startAndMove(x,y,col)
 136                 d='001001'                                                                              # Line style change, moveTo
 137                 l =[lengthSB(x),lengthSB(y)].max
 138                 d+=sprintf("%05b%0#{l}b%0#{l}b",l,x,y)
 139                 d+=col                                                                                  # Select line style
 140         end
 141
 142         def drawTo(absx,absy,x,y)
 143                 dx=x-absx
 144                 dy=y-absy
 145
 146     # Split the line up if there's anything>16383, because
 147     # that would overflow the 4 bits allowed for length
 148     mstep=[dx.abs/16383,dy.abs/16383,1].max.ceil
 149     xstep=dx/mstep
 150     ystep=dy/mstep
 151     d=''
 152     for i in (1..mstep)
 153       d+=drawSection(x,y,x+xstep,y+ystep)
 154       x+=xstep
 155       y+=ystep
 156     end
 157     d
 158         end
 159
 160         def drawSection(x1,y1,x2,y2)
 161                 d='11'                                                                                  # TypeFlag, EdgeFlag
 162           dx=x2-x1
 163           dy=y2-y1
 164                 l =[lengthSB(dx),lengthSB(dy)].max
 165                 d+=sprintf("%04b",l-2)
 166                 d+='1'                                                                                  # GeneralLine
 167                 d+=sprintf("%0#{l}b%0#{l}b",dx,dy)
 168   end
 169
 170         # -----------------------------------------------------------------------
 171         # Specific data types
 172
 173   # SWF data block type
 174
 175         def swfRecord(id,r)
 176                 if r.length>62
 177       # Long header: tag id, 0x3F, length
 178                         return packUI16((id<<6)+0x3F) + packUI32(r.length) + r
 179                 else
 180       # Short header: tag id, length
 181                         return packUI16((id<<6)+r.length) + r
 182                 end
 183         end
 184
 185   # SWF RECT type
 186
 187         def packRect(a,b,c,d)
 188                 l=[lengthSB(a),
 189                    lengthSB(b),
 190                    lengthSB(c),
 191                    lengthSB(d)].max
 192     # create binary string (00111001 etc.) - 5-byte length, then bbox
 193                 n=sprintf("%05b%0#{l}b%0#{l}b%0#{l}b%0#{l}b",l,a,b,c,d)
 194     # pack into byte string
 195                 [n].pack("B*")
 196         end
 197
 198         # -----------------------------------------------------------------------
 199         # Generic pack functions
 200
 201         def packUI16(n)
 202                 [n.floor].pack("v")
 203         end
 204
 205         def packUI32(n)
 206                 [n.floor].pack("V")
 207         end
 208
 209         # Find number of bits required to store arbitrary-length binary
 210
 211         def lengthSB(n)
 212                 Math.frexp(n+ (n==0?1:0) )[1]+1
 213         end
 214
 215         # ====================================================================
 216         # Co-ordinate conversion
 217         # (this is duplicated from amf_controller, should probably share)
 218
 219         def lat2coord(a,basey,masterscale)
 220                 -(lat2y(a)-basey)*masterscale
 221         end
 222
 223         def long2coord(a,baselong,masterscale)
 224                 (a-baselong)*masterscale
 225         end
 226
 227         def lat2y(a)
 228                 180/Math::PI * Math.log(Math.tan(Math::PI/4+a*(Math::PI/180)/2))
 229         end
 230
 231         def sqlescape(a)
 232                 a.gsub("'","''").gsub(92.chr,92.chr+92.chr)
 233         end
 234
 235 end