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