osrm startup helpers added

osrm/lib/guidance.lua

@@ -0,0 +1,146 @@
+local Tags = require('lib/tags')
+local Set = require('lib/set')
+
+local Guidance = {}
+
+-- Guidance: Default Mapping from roads to types/priorities
+highway_classes = {
+  motorway = road_priority_class.motorway,
+  motorway_link = road_priority_class.link_road,
+  trunk = road_priority_class.trunk,
+  trunk_link = road_priority_class.link_road,
+  primary = road_priority_class.primary,
+  primary_link = road_priority_class.link_road,
+  secondary = road_priority_class.secondary,
+  secondary_link = road_priority_class.link_road,
+  tertiary = road_priority_class.tertiary,
+  tertiary_link = road_priority_class.link_road,
+  unclassified = road_priority_class.side_residential,
+  residential = road_priority_class.side_residential,
+  service = road_priority_class.connectivity,
+  living_street = road_priority_class.main_residential,
+  track = road_priority_class.bike_path,
+  path = road_priority_class.bike_path,
+  footway = road_priority_class.foot_path,
+  pedestrian = road_priority_class.foot_path,
+  steps = road_priority_class.foot_path
+}
+
+default_highway_class = road_priority_class.connectivity;
+
+motorway_types = Set {
+  'motorway',
+  'motorway_link',
+  'trunk',
+  'trunk_link'
+}
+
+-- these road types are set with a car in mind. For bicycle/walk we probably need different ones
+road_types = Set {
+  'motorway',
+  'motorway_link',
+  'trunk',
+  'trunk_link',
+  'primary',
+  'primary_link',
+  'secondary',
+  'secondary_link',
+  'tertiary',
+  'tertiary_link',
+  'unclassified',
+  'residential',
+  'living_street'
+}
+
+link_types = Set {
+  'motorway_link',
+  'trunk_link',
+  'primary_link',
+  'secondary_link',
+  'tertiary_link'
+}
+
+function Guidance.set_classification (highway, result, input_way)
+  if motorway_types[highway] then
+    result.road_classification.motorway_class = true;
+  end
+  if link_types[highway] then
+    result.road_classification.link_class = true;
+  end
+  if highway_classes[highway] ~= nil then
+    result.road_classification.road_priority_class = highway_classes[highway]
+  else
+    result.road_classification.road_priority_class = default_highway_class
+  end
+  if road_types[highway] then
+    result.road_classification.may_be_ignored = false;
+  else
+    result.road_classification.may_be_ignored = true;
+  end
+
+  local lane_count = input_way:get_value_by_key("lanes")
+  if lane_count then
+    local lc = tonumber(lane_count)
+    if lc ~= nil then
+      result.road_classification.num_lanes = lc
+    end
+  else
+    local total_count = 0
+    local forward_count = input_way:get_value_by_key("lanes:forward")
+    if forward_count then
+      local fc = tonumber(forward_count)
+      if fc ~= nil then
+        total_count = fc
+      end
+    end
+    local backward_count = input_way:get_value_by_key("lanes:backward")
+    if backward_count then
+      local bc = tonumber(backward_count)
+      if bc ~= nil then
+        total_count = total_count + bc
+      end
+    end
+    if total_count ~= 0 then
+      result.road_classification.num_lanes = total_count
+    end
+  end
+end
+
+-- returns forward,backward psv lane count
+local function get_psv_counts(way,data)
+  local psv_forward, psv_backward = Tags.get_forward_backward_by_key(way,data,'lanes:psv')
+  if psv_forward then
+    psv_forward = tonumber(psv_forward)
+  end
+  if psv_backward then
+    psv_backward = tonumber(psv_backward)
+  end
+  return psv_forward or 0,
+         psv_backward or 0
+end
+
+-- trims lane string with regard to supported lanes
+local function process_lanes(turn_lanes,vehicle_lanes,first_count,second_count)
+  if turn_lanes then
+    if vehicle_lanes then
+      return applyAccessTokens(turn_lanes,vehicle_lanes)
+    elseif first_count ~= 0 or second_count ~= 0 then
+      return trimLaneString(turn_lanes, first_count, second_count)
+    else
+      return turn_lanes
+    end
+  end
+end
+
+-- this is broken for left-sided driving. It needs to switch left and right in case of left-sided driving
+function Guidance.get_turn_lanes(way,data)
+  local psv_fw, psv_bw = get_psv_counts(way,data)
+  local turn_lanes_fw, turn_lanes_bw = Tags.get_forward_backward_by_key(way,data,'turn:lanes')
+  local vehicle_lanes_fw, vehicle_lanes_bw = Tags.get_forward_backward_by_key(way,data,'vehicle:lanes')
+  
+  --note: backward lanes swap psv_bw and psv_fw
+  return process_lanes(turn_lanes_fw,vehicle_lanes_fw,psv_bw,psv_fw) or turn_lanes,
+         process_lanes(turn_lanes_bw,vehicle_lanes_bw,psv_fw,psv_bw) or turn_lanes
+end
+
+return Guidance