Potlatch-on-Rails, ready to go (fingers crossed)
[rails.git] / app / controllers / swf_controller.rb
1 class SwfController < ApplicationController
2
3 # to log:
4 # RAILS_DEFAULT_LOGGER.error("Args: #{args[0]}, #{args[1]}, #{args[2]}, #{args[3]}")
5 # $log.puts Time.new.to_s+','+Time.new.usec.to_s+": started GPS script"
6 # 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
7
8         # ====================================================================
9         # Public methods
10         
11         # ---- trackpoints      compile SWF of trackpoints
12
13         def trackpoints 
14         
15                 # -     Initialise
16         
17                 baselong        =params['baselong'].to_f
18                 basey           =params['basey'].to_f
19                 masterscale     =params['masterscale'].to_f
20         
21                 xmin=params['xmin'].to_f/0.0000001
22                 xmax=params['xmax'].to_f/0.0000001
23                 ymin=params['ymin'].to_f/0.0000001
24                 ymax=params['ymax'].to_f/0.0000001
25         
26                 # -     Begin movie
27         
28                 bounds_left  =0
29                 bounds_right =320*20
30                 bounds_bottom=0
31                 bounds_top   =240*20
32
33                 m =''
34                 m+=swfRecord(9,255.chr + 155.chr + 155.chr)                     #ƊBackground
35                 absx=0
36                 absy=0
37                 xl=yb= 9999999
38                 xr=yt=-9999999
39         
40                 # -     Send SQL and draw line
41         
42                 b=''
43                 lasttime=0
44                 lastfile='-1'
45         
46                 if params['token']
47                         token=sqlescape(params['token'])
48                         sql="SELECT gps_points.latitude*0.0000001 AS lat,gps_points.longitude*0.0000001 AS lon,gpx_files.id AS fileid,UNIX_TIMESTAMP(gps_points.timestamp) AS ts "+
49                                  " FROM gpx_files,gps_points,users "+
50                                  "WHERE gpx_files.id=gpx_id "+
51                                  "  AND gpx_files.user_id=users.id "+
52                                  "  AND token='#{token}' "+
53                                  "  AND (gps_points.longitude BETWEEN #{xmin} AND #{xmax}) "+
54                                  "  AND (gps_points.latitude BETWEEN #{ymin} AND #{ymax}) "+
55                                  "ORDER BY fileid DESC,ts "+
56                                  "LIMIT 10000"
57                 else
58                         sql="SELECT latitude*0.0000001 AS lat,longitude*0.0000001 AS lon,gpx_id AS fileid,UNIX_TIMESTAMP(timestamp) AS ts "+
59                                  " FROM gps_points "+
60                                  "WHERE (longitude BETWEEN #{xmin} AND #{xmax}) "+
61                                  "  AND (latitude  BETWEEN #{ymin} AND #{ymax}) "+
62                                  "ORDER BY fileid DESC,ts "+
63                                  "LIMIT 10000"
64                 end
65                 gpslist=ActiveRecord::Base.connection.select_all sql
66         
67                 # - Draw lines
68         
69                 r=startShape()
70                 gpslist.each do |row|
71                         xs=(long2coord(row['lon'].to_f,baselong,masterscale)*20).floor
72                         ys=(lat2coord(row['lat'].to_f ,basey   ,masterscale)*20).floor
73                         xl=[xs,xl].min; xr=[xs,xr].max
74                         yb=[ys,yb].min; yt=[ys,yt].max
75                         if (row['ts'].to_i-lasttime<180 and row['fileid']==lastfile)
76                                 b+=drawTo(absx,absy,xs,ys)
77                         else
78                                 b+=startAndMove(xs,ys)
79                         end
80                         absx=xs.floor; absy=ys.floor
81                         lasttime=row['ts'].to_i
82                         lastfile=row['fileid']
83                         while b.length>80 do
84                                 r+=[b.slice!(0...80)].pack("B*")
85                         end
86                 end
87         
88                 # - Write shape
89         
90                 b+=endShape()
91                 r+=[b].pack("B*")
92                 m+=swfRecord(2,packUI16(1) + packRect(xl,xr,yb,yt) + r)
93                 m+=swfRecord(4,packUI16(1) + packUI16(1))
94                 
95                 # -     Create Flash header and write to browser
96         
97                 m+=swfRecord(1,'')                                                                      # Show frame
98                 m+=swfRecord(0,'')                                                                      # End
99                 
100                 m=packRect(bounds_left,bounds_right,bounds_bottom,bounds_top) + 0.chr + 12.chr + packUI16(1) + m
101                 m='FWS' + 6.chr + packUI32(m.length+8) + m
102         
103                 response.headers["Content-Type"]="application/x-shockwave-flash"
104                 render :text=>m
105         end
106
107         private
108
109         # =======================================================================
110         # SWF functions
111         
112         # -----------------------------------------------------------------------
113         # Line-drawing
114
115         def startShape
116                 s =0.chr                                                                                # No fill styles
117                 s+=1.chr                                                                                # One line style
118                 s+=packUI16(5) + 0.chr + 255.chr + 255.chr              # Width 5, RGB #00FFFF
119                 s+=17.chr                                                                               # 1 fill, 1 line index bit
120                 s
121         end
122         
123         def endShape
124                 '000000'
125         end
126         
127         def startAndMove(x,y)
128                 d='001001'                                                                              # Line style change, moveTo
129                 l =[lengthSB(x),lengthSB(y)].max
130                 d+=sprintf("%05b%0#{l}b%0#{l}b",l,x,y)
131                 d+='1'                                                                                  # Select line style 1
132         end
133         
134         def drawTo(absx,absy,x,y)
135                 d='11'                                                                                  # TypeFlag, EdgeFlag
136                 dx=x-absx
137                 dy=y-absy
138                 
139                 l =[lengthSB(dx),lengthSB(dy)].max
140                 d+=sprintf("%04b",l-2)
141                 d+='1'                                                                                  # GeneralLine
142                 d+=sprintf("%0#{l}b%0#{l}b",dx,dy)
143         end
144
145         # -----------------------------------------------------------------------
146         # Specific data types
147
148         def swfRecord(id,r)
149                 if r.length>62
150                         return packUI16((id<<6)+0x3F) + packUI32(r.length) + r
151                 else
152                         return packUI16((id<<6)+r.length) + r
153                 end
154         end
155
156         def packRect(a,b,c,d)
157                 l=[lengthSB(a),
158                    lengthSB(b),
159                    lengthSB(c),
160                    lengthSB(d)].max
161                 n=sprintf("%05b%0#{l}b%0#{l}b%0#{l}b%0#{l}b",l,a,b,c,d)
162                 [n].pack("B*")
163         end
164
165         # -----------------------------------------------------------------------
166         # Generic pack functions
167         
168         def packUI16(n)
169                 [n.floor].pack("v")
170         end
171         
172         def packUI32(n)
173                 [n.floor].pack("V")
174         end
175         
176         # Find number of bits required to store arbitrary-length binary
177         
178         def lengthSB(n)
179                 Math.frexp(n+ (n==0?1:0) )[1]+1
180         end
181         
182         # ====================================================================
183         # Co-ordinate conversion
184         # (this is duplicated from amf_controller, should probably share)
185         
186         def lat2coord(a,basey,masterscale)
187                 -(lat2y(a)-basey)*masterscale+250
188         end
189         
190         def long2coord(a,baselong,masterscale)
191                 (a-baselong)*masterscale+350
192         end
193         
194         def lat2y(a)
195                 180/Math::PI * Math.log(Math.tan(Math::PI/4+a*(Math::PI/180)/2))
196         end
197
198         def sqlescape(a)
199                 a.gsub("'","''").gsub(92.chr,92.chr+92.chr)
200         end
201
202 end