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