app/controllers/swf_controller.rb

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