#STRATEGO - Smarter route finding

Moose Development/Moose/Functional/Stratego.lua

@@ -15,7 +15,7 @@
 -- 
 -- @module Functional.Stratego
 -- @image Functional.Stratego.png
--- Last Update April 2024
+-- Last Update May 2024
 
 
 ---
@@ -181,7 +181,7 @@ STRATEGO = {
   debug = false,
   drawzone = false,
   markzone = false,
-  version = "0.2.8",
+  version = "0.2.9",
   portweight = 3,
   POIweight = 1,
   maxrunways = 3,
@@ -212,9 +212,10 @@ STRATEGO = {
 -- @field #number coalition
 -- @field #boolean port
 -- @field Core.Zone#ZONE_RADIUS zone,
--- @field Core.Point#COORDINATRE coord
+-- @field Core.Point#COORDINATE coord
 -- @field #string type
 -- @field Ops.OpsZone#OPSZONE opszone
+-- @field #number connections
 
 ---
 -- @type STRATEGO.DistData
@@ -490,6 +491,7 @@ function STRATEGO:AnalyseBases()
         coord = coord,
         type = abtype,
         opszone = opszone,
+        connections = 0,
       }
       airbasetable[abname] = tbl
       nonconnectedab[abname] = true
@@ -576,10 +578,12 @@ function STRATEGO:AnalysePOIs(Set,Weight,Key)
         coord = coord,
         type = Key,
         opszone = opszone,
+        connections = 0,
       }
-      airbasetable[zone:GetName()] = tbl
+      airbasetable[zname] = tbl
-      nonconnectedab[zone:GetName()] = true
+      nonconnectedab[zname] = true
       local name = string.gsub(zname,"[%p%s]",".")
+      --self:I({name=name,zone=zname})
       easynames[name]=zname
     end
   )
@@ -598,6 +602,30 @@ function STRATEGO:GetToFrom(StartPoint,EndPoint)
   return fromto, tofrom
 end
 
+--- [USER] Get available connecting nodes from one start node
+-- @param #STRATEGO self
+-- @param #string StartPoint The starting name
+-- @return #boolean found
+-- @return #table Nodes 
+function STRATEGO:GetRoutesFromNode(StartPoint)
+  self:T(self.lid.."GetRoutesFromNode")
+  local pstart = string.gsub(StartPoint,"[%p%s]",".")
+  local found = false
+  pstart=pstart..";"
+  local routes = {}
+  local listed = {}
+  for _,_data in pairs(self.routexists) do
+    if string.find(_data,pstart,1,true) and not listed[_data] then
+      local target = string.gsub(_data,pstart,"")
+      local fname = self.easynames[target]
+      table.insert(routes,fname)
+      found = true
+      listed[_data] = true
+    end
+  end
+  return found,routes
+end
+
 --- [USER] Manually add a route, for e.g. Island hopping or to connect isolated networks. Use **after** STRATEGO has been started!
 -- @param #STRATEGO self
 -- @param #string Startpoint Starting Point, e.g. AIRBASE.Syria.Hatay
@@ -630,6 +658,8 @@ function STRATEGO:AddRoutesManually(Startpoint,Endpoint,Color,Linetype,Draw)
   local factor = self.airbasetable[Startpoint].baseweight*self.routefactor
   self.airbasetable[Startpoint].weight = self.airbasetable[Startpoint].weight+factor
   self.airbasetable[Endpoint].weight = self.airbasetable[Endpoint].weight+factor
+  self.airbasetable[Endpoint].connections = self.airbasetable[Endpoint].connections + 2
+  self.airbasetable[Startpoint].connections = self.airbasetable[Startpoint].connections+2
   if self.debug or Draw then
     startcoordinate:LineToAll(targetcoordinate,-1,color,1,linetype,nil,string.format("%dkm",dist))
   end
@@ -648,7 +678,7 @@ function STRATEGO:AnalyseRoutes(tgtrwys,factor,color,linetype)
       for _,_data in pairs(self.airbasetable) do
         local fromto,tofrom = self:GetToFrom(startpoint,_data.name) 
         if _data.name == startpoint then
-          -- sam as we
+          -- same as we
         elseif _data.baseweight == tgtrwys and not (self.routexists[fromto] or self.routexists[tofrom]) then
           local tgtc = _data.coord
           local dist = UTILS.Round(tgtc:Get2DDistance(startcoord),-2)/1000
@@ -670,6 +700,8 @@ function STRATEGO:AnalyseRoutes(tgtrwys,factor,color,linetype)
             self.nonconnectedab[startpoint] = false
             self.airbasetable[startpoint].weight = self.airbasetable[startpoint].weight+factor
             self.airbasetable[_data.name].weight = self.airbasetable[_data.name].weight+factor
+            self.airbasetable[startpoint].connections = self.airbasetable[startpoint].connections + 1
+            self.airbasetable[_data.name].connections = self.airbasetable[_data.name].connections + 1
             if self.debug then
               startcoord:LineToAll(tgtc,-1,color,1,linetype,nil,string.format("%dkm",dist))
             end
@@ -716,6 +748,8 @@ function STRATEGO:AnalyseUnconnected(Color)
        end
        self.airbasetable[startpoint].weight = self.airbasetable[startpoint].weight+1
        self.airbasetable[closest].weight = self.airbasetable[closest].weight+1
+       self.airbasetable[startpoint].connections = self.airbasetable[startpoint].connections+2
+       self.airbasetable[closest].connections = self.airbasetable[closest].connections+2
        local data = {
           start = startpoint,
           target = closest,
@@ -732,6 +766,38 @@ function STRATEGO:AnalyseUnconnected(Color)
   return self
 end
 
+--[[
+function STRATEGO:PruneDeadEnds(abtable)
+  local found = false
+  local newtable = {}
+  for name, _data in pairs(abtable) do
+    local data = _data -- #STRATEGO.Data
+    if data.connections > 2 then
+      newtable[name] = data     
+    else
+      -- dead end
+      found = true
+      local neighbors, nearest, distance  = self:FindNeighborNodes(name)
+      --self:I("Pruning "..name)
+      if nearest then
+        for _name,_ in pairs(neighbors) do
+          local abname = self.easynames[_name] or _name
+          --self:I({easyname=_name,airbasename=abname})
+          if abtable[abname] then
+            abtable[abname].connections = abtable[abname].connections -1 
+          end
+        end
+      end
+      if self.debug then
+        data.coord:CircleToAll(5000,-1,{1,1,1},1,{1,1,1},1,3,true,"Dead End")
+      end
+    end
+  end
+  abtable = nil
+  return found,newtable
+end
+--]]
+
 --- [USER] Get a list of the nodes with the highest weight.
 -- @param #STRATEGO self
 -- @param #number Coalition (Optional) Find for this coalition only. E.g. coalition.side.BLUE.
@@ -1141,29 +1207,34 @@ function STRATEGO:FindNeighborNodes(Name,Enemies,Friends)
   self:T(self.lid.."FindNeighborNodes")
   local neighbors = {}
   local name = string.gsub(Name,"[%p%s]",".")
+  --self:I({Name=Name,name=name})
   local shortestdist = 1000*1000
   local nearest = nil
   for _route,_data in pairs(self.disttable) do
     if string.find(_route,name,1,true) then
       local dist = self.disttable[_route] -- #STRATEGO.DistData
+      --self:I({route=_route,name=name})
       local tname = string.gsub(_route,name,"")
       local tname = string.gsub(tname,";","")
+      --self:I({tname=tname,cname=self.easynames[tname]})
       local cname = self.easynames[tname] -- name of target
-      local encoa = self.coalition == coalition.side.BLUE and coalition.side.RED or coalition.side.BLUE
+      if cname then
-      if Enemies == true then
+        local encoa = self.coalition == coalition.side.BLUE and coalition.side.RED or coalition.side.BLUE
-        if self.airbasetable[cname].coalition == encoa then
+        if Enemies == true then
-         neighbors[cname] = dist
+          if self.airbasetable[cname].coalition == encoa then
+           neighbors[cname] = dist
+          end
+        elseif Friends == true then
+          if self.airbasetable[cname].coalition ~= encoa then
+           neighbors[cname] = dist
+          end
+        else
+          neighbors[cname] = dist
         end
-      elseif Friends == true then
+        if neighbors[cname] and  dist.dist < shortestdist then 
-        if self.airbasetable[cname].coalition ~= encoa then
+          shortestdist = dist.dist
-         neighbors[cname] = dist
+          nearest = cname
         end
-      else
-        neighbors[cname] = dist
-      end
-      if neighbors[cname] and  dist.dist < shortestdist then 
-        shortestdist = dist.dist
-        nearest = cname
       end
     end
   end
@@ -1180,13 +1251,16 @@ end
 -- @param #number LineType (Optional) Line type: 0=No line, 1=Solid, 2=Dashed, 3=Dotted, 4=Dot dash, 5=Long dash, 6=Two dash. Default 6.
 -- @return #table Route Table of #string name entries of the route
 -- @return #boolean Complete If true, the route was found end-to-end.
+-- @return #boolean Reverse If true, the route was found with a reverse search, the route table will be from sorted from end point to start point.
 function STRATEGO:FindRoute(Start,End,Hops,Draw,Color,LineType)
   self:T(self.lid.."FindRoute")
   --self:I({Start,End,Hops})
   --local bases = UTILS.DeepCopy(self.airbasetable)
-  local Route = {}  
+  local Route = {}
+  local InRoute = {}  
   local hops = Hops or 4
   local routecomplete = false
+  local reverse = false
   
   local function Checker(neighbors)
     for _name,_data in pairs(neighbors) do
@@ -1200,13 +1274,16 @@ function STRATEGO:FindRoute(Start,End,Hops,Draw,Color,LineType)
   
   local function NextClosest(Start,End)
     local ecoord = self.airbasetable[End].coord
-    local nodes = self:FindNeighborNodes(Start)
+    local nodes,nearest = self:FindNeighborNodes(Start)
+    --self:I(tostring(nearest))
     local closest = nil
     local closedist = 1000*1000
     for _name,_dist in pairs(nodes) do
       local kcoord = self.airbasetable[_name].coord
+      local nnodes = self.airbasetable[_name].connections > 2 and true or false
+      if _name == End then nnodes = true end
       local dist = math.floor((kcoord:Get2DDistance(ecoord)/1000)+0.5)
-      if dist < closedist then
+      if (dist < closedist and nnodes and InRoute[_name] ~= true) then
         closedist = dist
         closest = _name
       end
@@ -1231,6 +1308,7 @@ function STRATEGO:FindRoute(Start,End,Hops,Draw,Color,LineType)
   
   -- One hop
   Route[#Route+1] = Start
+  InRoute[Start] = true
   local nodes = self:FindNeighborNodes(Start)
   local endpoint = Checker(nodes)
   
@@ -1240,9 +1318,11 @@ function STRATEGO:FindRoute(Start,End,Hops,Draw,Color,LineType)
   else
     local spoint = Start
     for i=1,hops do
+      --self:I("Start="..tostring(spoint))
       local Next = NextClosest(spoint,End)
       if Next then
         Route[#Route+1] = Next
+        InRoute[Next] = true
         local nodes = self:FindNeighborNodes(Next)
         local endpoint = Checker(nodes)
         if endpoint then
@@ -1255,8 +1335,54 @@ function STRATEGO:FindRoute(Start,End,Hops,Draw,Color,LineType)
       end
     end
   end
-  if (self.debug or Draw) then DrawRoute(Route) end 
+  
-  return Route, routecomplete
+  -- optimize route
+  local function OptimizeRoute(Route)
+    local foundcut = false
+    local largestcut = 0
+    local cut = {}
+    for i=1,#Route do
+      --self:I({Start=Route[i]})
+      local found,nodes = self:GetRoutesFromNode(Route[i])
+      for _,_name in pairs(nodes or {}) do
+        for j=i+2,#Route do      
+          if _name == Route[j] then
+            --self:I({"Shortcut",Route[i],Route[j]})          
+            if j-i > largestcut then
+              largestcut = j-i
+              cut = {i=i,j=j}
+              foundcut = true
+            end
+          end
+        end
+      end
+    end
+    if foundcut then
+      local newroute = {}
+      for i=1,#Route do
+        if i<= cut.i or i>=cut.j then
+          table.insert(newroute,Route[i])
+        end
+      end
+      return newroute
+    end
+    return Route, foundcut
+  end 
+  
+  if routecomplete == true then
+    local foundcut = true
+    while foundcut ~= false do
+      Route, foundcut = OptimizeRoute(Route)
+    end
+  else
+    -- reverse search
+    Route, routecomplete = self:FindRoute(End,Start,Hops,Draw,Color,LineType)
+    reverse = true
+  end
+  
+  if (self.debug or Draw) then DrawRoute(Route) end
+  
+  return Route, routecomplete, reverse
 end
 
 --- [USER] Add budget points.