-module Api
- class SwfController < ApiController
- before_action :check_api_readable
- authorize_resource :class => false
-
- # to log:
- # RAILS_DEFAULT_LOGGER.error("Args: #{args[0]}, #{args[1]}, #{args[2]}, #{args[3]}")
- # $log.puts Time.new.to_s+','+Time.new.usec.to_s+": started GPS script"
- # 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
-
- # ====================================================================
- # Public methods
-
- # ---- trackpoints compile SWF of trackpoints
-
- def trackpoints
- # - Initialise
-
- baselong = params["baselong"].to_f
- basey = params["basey"].to_f
- masterscale = params["masterscale"].to_f
-
- bbox = BoundingBox.new(params["xmin"], params["ymin"],
- params["xmax"], params["ymax"])
- start = params["start"].to_i
-
- # - Begin movie
-
- bounds_left = 0
- bounds_right = 320 * 20
- bounds_bottom = 0
- bounds_top = 240 * 20
-
- m = ""
- m += swf_record(9, 255.chr + 155.chr + 155.chr) # Background
- absx = 0
- absy = 0
- xl = yb = 9999999
- xr = yt = -9999999
-
- # - Send SQL for GPS tracks
-
- b = ""
- lasttime = 0
- lasttrack = lastfile = "-1"
-
- if params["token"]
- user = User.authenticate(:token => params[:token])
- 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, gps_points.trackid AS trackid " + " FROM gpx_files,gps_points " + "WHERE gpx_files.id=gpx_id " + " AND gpx_files.user_id=#{user.id} " + " AND " + OSM.sql_for_area(bbox, "gps_points.") + " AND (gps_points.timestamp IS NOT NULL) " + "ORDER BY fileid DESC,ts " + "LIMIT 10000 OFFSET #{start}"
- else
- sql = "SELECT latitude*0.0000001 AS lat,longitude*0.0000001 AS lon,gpx_id AS fileid," + " EXTRACT(EPOCH FROM timestamp) AS ts, gps_points.trackid AS trackid " + " FROM gps_points " + "WHERE " + OSM.sql_for_area(bbox, "gps_points.") + " AND (gps_points.timestamp IS NOT NULL) " + "ORDER BY fileid DESC,ts " + "LIMIT 10000 OFFSET #{start}"
- end
- gpslist = ActiveRecord::Base.connection.select_all sql
-
- # - Draw GPS trace lines
-
- r = start_shape
- gpslist.each do |row|
- xs = (long2coord(row["lon"].to_f, baselong, masterscale) * 20).floor
- ys = (lat2coord(row["lat"].to_f, basey, masterscale) * 20).floor
- xl = [xs, xl].min
- xr = [xs, xr].max
- yb = [ys, yb].min
- yt = [ys, yt].max
- if row["ts"].to_i - lasttime > 180 || row["fileid"] != lastfile || row["trackid"] != lasttrack # or row['ts'].to_i==lasttime
- b += start_and_move(xs, ys, "01")
- absx = xs.floor
- absy = ys.floor
- end
- b += draw_to(absx, absy, xs, ys)
- absx = xs.floor
- absy = ys.floor
- lasttime = row["ts"].to_i
- lastfile = row["fileid"]
- lasttrack = row["trackid"]
- r += [b.slice!(0...80)].pack("B*") while b.length > 80
- end
-
- # (Unwayed segments removed)
-
- # - Write shape
-
- b += end_shape
- r += [b].pack("B*")
- m += swf_record(2, pack_u16(1) + pack_rect(xl, xr, yb, yt) + r)
- m += swf_record(4, pack_u16(1) + pack_u16(1))
-
- # - Create Flash header and write to browser
-
- m += swf_record(1, "") # Show frame
- m += swf_record(0, "") # End
-
- m = pack_rect(bounds_left, bounds_right, bounds_bottom, bounds_top) + 0.chr + 12.chr + pack_u16(1) + m
- m = "FWS" + 6.chr + pack_u32(m.length + 8) + m
-
- render :body => m, :content_type => "application/x-shockwave-flash"
- end
-
- private
-
- # =======================================================================
- # SWF functions
-
- # -----------------------------------------------------------------------
- # Line-drawing
-
- def start_shape
- s = 0.chr # No fill styles
- s += 2.chr # Two line styles
- s += pack_u16(0) + 0.chr + 255.chr + 255.chr # Width 5, RGB #00FFFF
- s += pack_u16(0) + 255.chr + 0.chr + 255.chr # Width 5, RGB #FF00FF
- s += 34.chr # 2 fill, 2 line index bits
- s
- end
-
- def end_shape
- "000000"
- end
-
- def start_and_move(x, y, col)
- d = "001001" # Line style change, moveTo
- l = [length_sb(x), length_sb(y)].max
- d += format("%05b%0*b%0*b", l, l, x, l, y)
- d += col # Select line style
- d
- end
-
- def draw_to(absx, absy, x, y)
- dx = x - absx
- dy = y - absy
-
- # Split the line up if there's anything>16383, because
- # that would overflow the 4 bits allowed for length
- mstep = [dx.abs / 16383, dy.abs / 16383, 1].max.ceil
- xstep = dx / mstep
- ystep = dy / mstep
- d = ""
- 1.upto(mstep).each do
- d += draw_section(x, y, x + xstep, y + ystep)
- x += xstep
- y += ystep
- end
- d
- end
-
- def draw_section(x1, y1, x2, y2)
- d = "11" # TypeFlag, EdgeFlag
- dx = x2 - x1
- dy = y2 - y1
- l = [length_sb(dx), length_sb(dy)].max
- d += format("%04b", l - 2)
- d += "1" # GeneralLine
- d += format("%0*b%0*b", l, dx, l, dy)
- d
- end
-
- # -----------------------------------------------------------------------
- # Specific data types
-
- # SWF data block type
-
- def swf_record(id, r)
- if r.length > 62
- # Long header: tag id, 0x3F, length
- pack_u16((id << 6) + 0x3F) + pack_u32(r.length) + r
- else
- # Short header: tag id, length
- pack_u16((id << 6) + r.length) + r
- end
- end
-
- # SWF RECT type
-
- def pack_rect(a, b, c, d)
- l = [length_sb(a),
- length_sb(b),
- length_sb(c),
- length_sb(d)].max
- # create binary string (00111001 etc.) - 5-byte length, then bbox
- n = format("%05b%0*b%0*b%0*b%0*b", l, l, a, l, b, l, c, l, d)
- # pack into byte string
- [n].pack("B*")
- end
-
- # -----------------------------------------------------------------------
- # Generic pack functions
-
- def pack_u16(n)
- [n.floor].pack("v")
- end
-
- def pack_u32(n)
- [n.floor].pack("V")
- end
-
- # Find number of bits required to store arbitrary-length binary
-
- def length_sb(n)
- Math.frexp(n + (n.zero? ? 1 : 0))[1] + 1
- end
-
- # ====================================================================
- # Co-ordinate conversion
- # (this is duplicated from amf_controller, should probably share)
-
- def lat2coord(a, basey, masterscale)
- -(lat2y(a) - basey) * masterscale
- end
-
- def long2coord(a, baselong, masterscale)
- (a - baselong) * masterscale
- end
-
- def lat2y(a)
- 180 / Math::PI * Math.log(Math.tan(Math::PI / 4 + a * (Math::PI / 180) / 2))
- end
- end
-end