Frank 24f8116fce OPS
**ZONE**
- Fixed incorrect fillcolor alpha.

**COORDINATE**
- Fixed incorrect fillcolor alpha.

**AUFTRAG**
- Fixed `CASENHANCED` order of arguments wrong in docs.

**FLEET**
- Improved docs.
- Added ``:SetPathfinding` function

**OPSGROUP**
- Fixed RECON mission behaviour if not random.
- Improved stuck check if engaging.

**LEGION**
- Added weapon type as parameter for selecting cohort assets.

**COHORT**
- Added `:GetMissionRange` function that accounts for long range weapons.
- Added counting of asset ammo.
2022-04-13 22:39:48 +02:00

943 lines
29 KiB
Lua

--- **Core** - A* Pathfinding.
--
-- **Main Features:**
--
-- * Find path from A to B.
-- * Pre-defined as well as custom valid neighbour functions.
-- * Pre-defined as well as custom cost functions.
-- * Easy rectangular grid setup.
--
-- ===
--
-- ### Author: **funkyfranky**
--
-- ===
-- @module Core.Astar
-- @image CORE_Astar.png
--- ASTAR class.
-- @type ASTAR
-- @field #string ClassName Name of the class.
-- @field #boolean Debug Debug mode. Messages to all about status.
-- @field #string lid Class id string for output to DCS log file.
-- @field #table nodes Table of nodes.
-- @field #number counter Node counter.
-- @field #number Nnodes Number of nodes.
-- @field #number nvalid Number of nvalid calls.
-- @field #number nvalidcache Number of cached valid evals.
-- @field #number ncost Number of cost evaluations.
-- @field #number ncostcache Number of cached cost evals.
-- @field #ASTAR.Node startNode Start node.
-- @field #ASTAR.Node endNode End node.
-- @field Core.Point#COORDINATE startCoord Start coordinate.
-- @field Core.Point#COORDINATE endCoord End coordinate.
-- @field #function ValidNeighbourFunc Function to check if a node is valid.
-- @field #table ValidNeighbourArg Optional arguments passed to the valid neighbour function.
-- @field #function CostFunc Function to calculate the heuristic "cost" to go from one node to another.
-- @field #table CostArg Optional arguments passed to the cost function.
-- @extends Core.Base#BASE
--- *When nothing goes right... Go left!*
--
-- ===
--
-- # The ASTAR Concept
--
-- Pathfinding algorithm.
--
--
-- # Start and Goal
--
-- The first thing we need to define is obviously the place where we want to start and where we want to go eventually.
--
-- ## Start
--
-- The start
--
-- ## Goal
--
--
-- # Nodes
--
-- ## Rectangular Grid
--
-- A rectangular grid can be created using the @{#ASTAR.CreateGrid}(*ValidSurfaceTypes, BoxHY, SpaceX, deltaX, deltaY, MarkGrid*), where
--
-- * *ValidSurfaceTypes* is a table of valid surface types. By default all surface types are valid.
-- * *BoxXY* is the width of the grid perpendicular the the line between start and end node. Default is 40,000 meters (40 km).
-- * *SpaceX* is the additional space behind the start and end nodes. Default is 20,000 meters (20 km).
-- * *deltaX* is the grid spacing between nodes in the direction of start and end node. Default is 2,000 meters (2 km).
-- * *deltaY* is the grid spacing perpendicular to the direction of start and end node. Default is the same as *deltaX*.
-- * *MarkGrid* If set to *true*, this places marker on the F10 map on each grid node. Note that this can stall DCS if too many nodes are created.
--
-- ## Valid Surfaces
--
-- Certain unit types can only travel on certain surfaces types, for example
--
-- * Naval units can only travel on water (that also excludes shallow water in DCS currently),
-- * Ground units can only traval on land.
--
-- By restricting the surface type in the grid construction, we also reduce the number of nodes, which makes the algorithm more efficient.
--
-- ## Box Width (BoxHY)
--
-- The box width needs to be large enough to capture all paths you want to consider.
--
-- ## Space in X
--
-- The space in X value is important if the algorithm needs to to backwards from the start node or needs to extend even further than the end node.
--
-- ## Grid Spacing
--
-- The grid spacing is an important factor as it determines the number of nodes and hence the performance of the algorithm. It should be as large as possible.
-- However, if the value is too large, the algorithm might fail to get a valid path.
--
-- A good estimate of the grid spacing is to set it to be smaller (~ half the size) of the smallest gap you need to path.
--
-- # Valid Neighbours
--
-- The A* algorithm needs to know if a transition from one node to another is allowed or not. By default, hopping from one node to another is always possible.
--
-- ## Line of Sight
--
-- For naval
--
--
-- # Heuristic Cost
--
-- In order to determine the optimal path, the pathfinding algorithm needs to know, how costly it is to go from one node to another.
-- Often, this can simply be determined by the distance between two nodes. Therefore, the default cost function is set to be the 2D distance between two nodes.
--
--
-- # Calculate the Path
--
-- Finally, we have to calculate the path. This is done by the @{ASTAR.GetPath}(*ExcludeStart, ExcludeEnd*) function. This function returns a table of nodes, which
-- describe the optimal path from the start node to the end node.
--
-- By default, the start and end node are include in the table that is returned.
--
-- Note that a valid path must not always exist. So you should check if the function returns *nil*.
--
-- Common reasons that a path cannot be found are:
--
-- * The grid is too small ==> increase grid size, e.g. *BoxHY* and/or *SpaceX* if you use a rectangular grid.
-- * The grid spacing is too large ==> decrease *deltaX* and/or *deltaY*
-- * There simply is no valid path ==> you are screwed :(
--
--
-- # Examples
--
-- ## Strait of Hormuz
--
-- Carrier Group finds its way through the Stait of Hormuz.
--
-- ##
--
--
--
-- @field #ASTAR
ASTAR = {
ClassName = "ASTAR",
Debug = nil,
lid = nil,
nodes = {},
counter = 1,
Nnodes = 0,
ncost = 0,
ncostcache = 0,
nvalid = 0,
nvalidcache = 0,
}
--- Node data.
-- @type ASTAR.Node
-- @field #number id Node id.
-- @field Core.Point#COORDINATE coordinate Coordinate of the node.
-- @field #number surfacetype Surface type.
-- @field #table valid Cached valid/invalid nodes.
-- @field #table cost Cached cost.
--- ASTAR infinity.
-- @field #number INF
ASTAR.INF=1/0
--- ASTAR class version.
-- @field #string version
ASTAR.version="0.4.0"
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-- TODO list
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-- TODO: Add more valid neighbour functions.
-- TODO: Write docs.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-- Constructor
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--- Create a new ASTAR object.
-- @param #ASTAR self
-- @return #ASTAR self
function ASTAR:New()
-- Inherit everything from INTEL class.
local self=BASE:Inherit(self, BASE:New()) --#ASTAR
self.lid="ASTAR | "
return self
end
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-- User functions
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--- Set coordinate from where to start.
-- @param #ASTAR self
-- @param Core.Point#COORDINATE Coordinate Start coordinate.
-- @return #ASTAR self
function ASTAR:SetStartCoordinate(Coordinate)
self.startCoord=Coordinate
return self
end
--- Set coordinate where you want to go.
-- @param #ASTAR self
-- @param Core.Point#COORDINATE Coordinate end coordinate.
-- @return #ASTAR self
function ASTAR:SetEndCoordinate(Coordinate)
self.endCoord=Coordinate
return self
end
--- Create a node from a given coordinate.
-- @param #ASTAR self
-- @param Core.Point#COORDINATE Coordinate The coordinate where to create the node.
-- @return #ASTAR.Node The node.
function ASTAR:GetNodeFromCoordinate(Coordinate)
local node={} --#ASTAR.Node
node.coordinate=Coordinate
node.surfacetype=Coordinate:GetSurfaceType()
node.id=self.counter
node.valid={}
node.cost={}
self.counter=self.counter+1
return node
end
--- Add a node to the table of grid nodes.
-- @param #ASTAR self
-- @param #ASTAR.Node Node The node to be added.
-- @return #ASTAR self
function ASTAR:AddNode(Node)
self.nodes[Node.id]=Node
self.Nnodes=self.Nnodes+1
return self
end
--- Add a node to the table of grid nodes specifying its coordinate.
-- @param #ASTAR self
-- @param Core.Point#COORDINATE Coordinate The coordinate where the node is created.
-- @return #ASTAR.Node The node.
function ASTAR:AddNodeFromCoordinate(Coordinate)
local node=self:GetNodeFromCoordinate(Coordinate)
self:AddNode(node)
return node
end
--- Check if the coordinate of a node has is at a valid surface type.
-- @param #ASTAR self
-- @param #ASTAR.Node Node The node to be added.
-- @param #table SurfaceTypes Surface types, for example `{land.SurfaceType.WATER}`. By default all surface types are valid.
-- @return #boolean If true, surface type of node is valid.
function ASTAR:CheckValidSurfaceType(Node, SurfaceTypes)
if SurfaceTypes then
if type(SurfaceTypes)~="table" then
SurfaceTypes={SurfaceTypes}
end
for _,surface in pairs(SurfaceTypes) do
if surface==Node.surfacetype then
return true
end
end
return false
else
return true
end
end
--- Add a function to determine if a neighbour of a node is valid.
-- @param #ASTAR self
-- @param #function NeighbourFunction Function that needs to return *true* for a neighbour to be valid.
-- @param ... Condition function arguments if any.
-- @return #ASTAR self
function ASTAR:SetValidNeighbourFunction(NeighbourFunction, ...)
self.ValidNeighbourFunc=NeighbourFunction
self.ValidNeighbourArg={}
if arg then
self.ValidNeighbourArg=arg
end
return self
end
--- Set valid neighbours to require line of sight between two nodes.
-- @param #ASTAR self
-- @param #number CorridorWidth Width of LoS corridor in meters.
-- @return #ASTAR self
function ASTAR:SetValidNeighbourLoS(CorridorWidth)
self:SetValidNeighbourFunction(ASTAR.LoS, CorridorWidth)
return self
end
--- Set valid neighbours to be in a certain distance.
-- @param #ASTAR self
-- @param #number MaxDistance Max distance between nodes in meters. Default is 2000 m.
-- @return #ASTAR self
function ASTAR:SetValidNeighbourDistance(MaxDistance)
self:SetValidNeighbourFunction(ASTAR.DistMax, MaxDistance)
return self
end
--- Set valid neighbours to be in a certain distance.
-- @param #ASTAR self
-- @param #number MaxDistance Max distance between nodes in meters. Default is 2000 m.
-- @return #ASTAR self
function ASTAR:SetValidNeighbourRoad(MaxDistance)
self:SetValidNeighbourFunction(ASTAR.Road, MaxDistance)
return self
end
--- Set the function which calculates the "cost" to go from one to another node.
-- The first to arguments of this function are always the two nodes under consideration. But you can add optional arguments.
-- Very often the distance between nodes is a good measure for the cost.
-- @param #ASTAR self
-- @param #function CostFunction Function that returns the "cost".
-- @param ... Condition function arguments if any.
-- @return #ASTAR self
function ASTAR:SetCostFunction(CostFunction, ...)
self.CostFunc=CostFunction
self.CostArg={}
if arg then
self.CostArg=arg
end
return self
end
--- Set heuristic cost to go from one node to another to be their 2D distance.
-- @param #ASTAR self
-- @return #ASTAR self
function ASTAR:SetCostDist2D()
self:SetCostFunction(ASTAR.Dist2D)
return self
end
--- Set heuristic cost to go from one node to another to be their 3D distance.
-- @param #ASTAR self
-- @return #ASTAR self
function ASTAR:SetCostDist3D()
self:SetCostFunction(ASTAR.Dist3D)
return self
end
--- Set heuristic cost to go from one node to another to be their 3D distance.
-- @param #ASTAR self
-- @return #ASTAR self
function ASTAR:SetCostRoad()
self:SetCostFunction(ASTAR)
return self
end
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-- Grid functions
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--- Create a rectangular grid of nodes between star and end coordinate.
-- The coordinate system is oriented along the line between start and end point.
-- @param #ASTAR self
-- @param #table ValidSurfaceTypes Valid surface types. By default is all surfaces are allowed.
-- @param #number BoxHY Box "height" in meters along the y-coordinate. Default 40000 meters (40 km).
-- @param #number SpaceX Additional space in meters before start and after end coordinate. Default 10000 meters (10 km).
-- @param #number deltaX Increment in the direction of start to end coordinate in meters. Default 2000 meters.
-- @param #number deltaY Increment perpendicular to the direction of start to end coordinate in meters. Default is same as deltaX.
-- @param #boolean MarkGrid If true, create F10 map markers at grid nodes.
-- @return #ASTAR self
function ASTAR:CreateGrid(ValidSurfaceTypes, BoxHY, SpaceX, deltaX, deltaY, MarkGrid)
-- Note that internally
-- x coordinate is z: x-->z Line from start to end
-- y coordinate is x: y-->x Perpendicular
-- Grid length and width.
local Dz=SpaceX or 10000
local Dx=BoxHY and BoxHY/2 or 20000
-- Increments.
local dz=deltaX or 2000
local dx=deltaY or dz
-- Heading from start to end coordinate.
local angle=self.startCoord:HeadingTo(self.endCoord)
--Distance between start and end.
local dist=self.startCoord:Get2DDistance(self.endCoord)+2*Dz
-- Origin of map. Needed to translate back to wanted position.
local co=COORDINATE:New(0, 0, 0)
local do1=co:Get2DDistance(self.startCoord)
local ho1=co:HeadingTo(self.startCoord)
-- Start of grid.
local xmin=-Dx
local zmin=-Dz
-- Number of grid points.
local nz=dist/dz+1
local nx=2*Dx/dx+1
-- Debug info.
local text=string.format("Building grid with nx=%d ny=%d => total=%d nodes", nx, nz, nx*nz)
self:T(self.lid..text)
-- Loop over x and z coordinate to create a 2D grid.
for i=1,nx do
-- x coordinate perpendicular to z.
local x=xmin+dx*(i-1)
for j=1,nz do
-- z coordinate connecting start and end.
local z=zmin+dz*(j-1)
-- Rotate 2D.
local vec3=UTILS.Rotate2D({x=x, y=0, z=z}, angle)
-- Coordinate of the node.
local c=COORDINATE:New(vec3.z, vec3.y, vec3.x):Translate(do1, ho1, true)
-- Create a node at this coordinate.
local node=self:GetNodeFromCoordinate(c)
-- Check if node has valid surface type.
if self:CheckValidSurfaceType(node, ValidSurfaceTypes) then
if MarkGrid then
c:MarkToAll(string.format("i=%d, j=%d surface=%d", i, j, node.surfacetype))
end
-- Add node to grid.
self:AddNode(node)
end
end
end
-- Debug info.
local text=string.format("Done building grid!")
self:T2(self.lid..text)
return self
end
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-- Valid neighbour functions
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--- Function to check if two nodes have line of sight (LoS).
-- @param #ASTAR.Node nodeA First node.
-- @param #ASTAR.Node nodeB Other node.
-- @param #number corridor (Optional) Width of corridor in meters.
-- @return #boolean If true, two nodes have LoS.
function ASTAR.LoS(nodeA, nodeB, corridor)
local offset=1
local dx=corridor and corridor/2 or nil
local dy=dx
local cA=nodeA.coordinate:GetVec3()
local cB=nodeB.coordinate:GetVec3()
cA.y=offset
cB.y=offset
local los=land.isVisible(cA, cB)
if los and corridor then
-- Heading from A to B.
local heading=nodeA.coordinate:HeadingTo(nodeB.coordinate)
local Ap=UTILS.VecTranslate(cA, dx, heading+90)
local Bp=UTILS.VecTranslate(cB, dx, heading+90)
los=land.isVisible(Ap, Bp)
if los then
local Am=UTILS.VecTranslate(cA, dx, heading-90)
local Bm=UTILS.VecTranslate(cB, dx, heading-90)
los=land.isVisible(Am, Bm)
end
end
return los
end
--- Function to check if two nodes have a road connection.
-- @param #ASTAR.Node nodeA First node.
-- @param #ASTAR.Node nodeB Other node.
-- @return #boolean If true, two nodes are connected via a road.
function ASTAR.Road(nodeA, nodeB)
local path=land.findPathOnRoads("roads", nodeA.coordinate.x, nodeA.coordinate.z, nodeB.coordinate.x, nodeB.coordinate.z)
if path then
return true
else
return false
end
end
--- Function to check if distance between two nodes is less than a threshold distance.
-- @param #ASTAR.Node nodeA First node.
-- @param #ASTAR.Node nodeB Other node.
-- @param #number distmax Max distance in meters. Default is 2000 m.
-- @return #boolean If true, distance between the two nodes is below threshold.
function ASTAR.DistMax(nodeA, nodeB, distmax)
distmax=distmax or 2000
local dist=nodeA.coordinate:Get2DDistance(nodeB.coordinate)
return dist<=distmax
end
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-- Heuristic cost functions
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--- Heuristic cost is given by the 2D distance between the nodes.
-- @param #ASTAR.Node nodeA First node.
-- @param #ASTAR.Node nodeB Other node.
-- @return #number Distance between the two nodes.
function ASTAR.Dist2D(nodeA, nodeB)
local dist=nodeA.coordinate:Get2DDistance(nodeB)
return dist
end
--- Heuristic cost is given by the 3D distance between the nodes.
-- @param #ASTAR.Node nodeA First node.
-- @param #ASTAR.Node nodeB Other node.
-- @return #number Distance between the two nodes.
function ASTAR.Dist3D(nodeA, nodeB)
local dist=nodeA.coordinate:Get3DDistance(nodeB.coordinate)
return dist
end
--- Heuristic cost is given by the distance between the nodes on road.
-- @param #ASTAR.Node nodeA First node.
-- @param #ASTAR.Node nodeB Other node.
-- @return #number Distance between the two nodes.
function ASTAR.DistRoad(nodeA, nodeB)
-- Get the path.
local path=land.findPathOnRoads("roads", nodeA.coordinate.x, nodeA.coordinate.z, nodeB.coordinate.x, nodeB.coordinate.z)
if path then
local dist=0
for i=2,#path do
local b=path[i] --DCS#Vec2
local a=path[i-1] --DCS#Vec2
dist=dist+UTILS.VecDist2D(a,b)
end
return dist
end
return math.huge
end
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-- Misc functions
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--- Find the closest node from a given coordinate.
-- @param #ASTAR self
-- @param Core.Point#COORDINATE Coordinate.
-- @return #ASTAR.Node Cloest node to the coordinate.
-- @return #number Distance to closest node in meters.
function ASTAR:FindClosestNode(Coordinate)
local distMin=math.huge
local closeNode=nil
for _,_node in pairs(self.nodes) do
local node=_node --#ASTAR.Node
local dist=node.coordinate:Get2DDistance(Coordinate)
if dist<distMin then
distMin=dist
closeNode=node
end
end
return closeNode, distMin
end
--- Find the start node.
-- @param #ASTAR self
-- @param #ASTAR.Node Node The node to be added to the nodes table.
-- @return #ASTAR self
function ASTAR:FindStartNode()
local node, dist=self:FindClosestNode(self.startCoord)
self.startNode=node
if dist>1000 then
self:T(self.lid.."Adding start node to node grid!")
self:AddNode(node)
end
return self
end
--- Add a node.
-- @param #ASTAR self
-- @param #ASTAR.Node Node The node to be added to the nodes table.
-- @return #ASTAR self
function ASTAR:FindEndNode()
local node, dist=self:FindClosestNode(self.endCoord)
self.endNode=node
if dist>1000 then
self:T(self.lid.."Adding end node to node grid!")
self:AddNode(node)
end
return self
end
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-- Main A* pathfinding function
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--- A* pathfinding function. This seaches the path along nodes between start and end nodes/coordinates.
-- @param #ASTAR self
-- @param #boolean ExcludeStartNode If *true*, do not include start node in found path. Default is to include it.
-- @param #boolean ExcludeEndNode If *true*, do not include end node in found path. Default is to include it.
-- @return #table Table of nodes from start to finish.
function ASTAR:GetPath(ExcludeStartNode, ExcludeEndNode)
self:FindStartNode()
self:FindEndNode()
local nodes=self.nodes
local start=self.startNode
local goal=self.endNode
-- Sets.
local openset = {}
local closedset = {}
local came_from = {}
local g_score = {}
local f_score = {}
openset[start.id]=true
local Nopen=1
-- Initial scores.
g_score[start.id]=0
f_score[start.id]=g_score[start.id]+self:_HeuristicCost(start, goal)
-- Set start time.
local T0=timer.getAbsTime()
-- Debug message.
local text=string.format("Starting A* pathfinding with %d Nodes", self.Nnodes)
self:T(self.lid..text)
local Tstart=UTILS.GetOSTime()
-- Loop while we still have an open set.
while Nopen > 0 do
-- Get current node.
local current=self:_LowestFscore(openset, f_score)
-- Check if we are at the end node.
if current.id==goal.id then
local path=self:_UnwindPath({}, came_from, goal)
if not ExcludeEndNode then
table.insert(path, goal)
end
if ExcludeStartNode then
table.remove(path, 1)
end
local Tstop=UTILS.GetOSTime()
local dT=nil
if Tstart and Tstop then
dT=Tstop-Tstart
end
-- Debug message.
local text=string.format("Found path with %d nodes (%d total)", #path, self.Nnodes)
if dT then
text=text..string.format(", OS Time %.6f sec", dT)
end
text=text..string.format(", Nvalid=%d [%d cached]", self.nvalid, self.nvalidcache)
text=text..string.format(", Ncost=%d [%d cached]", self.ncost, self.ncostcache)
self:T(self.lid..text)
return path
end
-- Move Node from open to closed set.
openset[current.id]=nil
Nopen=Nopen-1
closedset[current.id]=true
-- Get neighbour nodes.
local neighbors=self:_NeighbourNodes(current, nodes)
-- Loop over neighbours.
for _,neighbor in pairs(neighbors) do
if self:_NotIn(closedset, neighbor.id) then
local tentative_g_score=g_score[current.id]+self:_DistNodes(current, neighbor)
if self:_NotIn(openset, neighbor.id) or tentative_g_score < g_score[neighbor.id] then
came_from[neighbor]=current
g_score[neighbor.id]=tentative_g_score
f_score[neighbor.id]=g_score[neighbor.id]+self:_HeuristicCost(neighbor, goal)
if self:_NotIn(openset, neighbor.id) then
-- Add to open set.
openset[neighbor.id]=true
Nopen=Nopen+1
end
end
end
end
end
-- Debug message.
local text=string.format("WARNING: Could NOT find valid path!")
self:E(self.lid..text)
MESSAGE:New(text, 60, "ASTAR"):ToAllIf(self.Debug)
return nil -- no valid path
end
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-- A* pathfinding helper functions
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--- Heuristic "cost" function to go from node A to node B. Default is the distance between the nodes.
-- @param #ASTAR self
-- @param #ASTAR.Node nodeA Node A.
-- @param #ASTAR.Node nodeB Node B.
-- @return #number "Cost" to go from node A to node B.
function ASTAR:_HeuristicCost(nodeA, nodeB)
-- Counter.
self.ncost=self.ncost+1
-- Get chached cost if available.
local cost=nodeA.cost[nodeB.id]
if cost~=nil then
self.ncostcache=self.ncostcache+1
return cost
end
local cost=nil
if self.CostFunc then
cost=self.CostFunc(nodeA, nodeB, unpack(self.CostArg))
else
cost=self:_DistNodes(nodeA, nodeB)
end
nodeA.cost[nodeB.id]=cost
nodeB.cost[nodeA.id]=cost -- Symmetric problem.
return cost
end
--- Check if going from a node to a neighbour is possible.
-- @param #ASTAR self
-- @param #ASTAR.Node node A node.
-- @param #ASTAR.Node neighbor Neighbour node.
-- @return #boolean If true, transition between nodes is possible.
function ASTAR:_IsValidNeighbour(node, neighbor)
-- Counter.
self.nvalid=self.nvalid+1
local valid=node.valid[neighbor.id]
if valid~=nil then
--env.info(string.format("Node %d has valid=%s neighbour %d", node.id, tostring(valid), neighbor.id))
self.nvalidcache=self.nvalidcache+1
return valid
end
local valid=nil
if self.ValidNeighbourFunc then
valid=self.ValidNeighbourFunc(node, neighbor, unpack(self.ValidNeighbourArg))
else
valid=true
end
node.valid[neighbor.id]=valid
neighbor.valid[node.id]=valid -- Symmetric problem.
return valid
end
--- Calculate 2D distance between two nodes.
-- @param #ASTAR self
-- @param #ASTAR.Node nodeA Node A.
-- @param #ASTAR.Node nodeB Node B.
-- @return #number Distance between nodes in meters.
function ASTAR:_DistNodes(nodeA, nodeB)
return nodeA.coordinate:Get2DDistance(nodeB.coordinate)
end
--- Function that calculates the lowest F score.
-- @param #ASTAR self
-- @param #table set The set of nodes IDs.
-- @param #number f_score F score.
-- @return #ASTAR.Node Best node.
function ASTAR:_LowestFscore(set, f_score)
local lowest, bestNode = ASTAR.INF, nil
for nid,node in pairs(set) do
local score=f_score[nid]
if score<lowest then
lowest, bestNode = score, nid
end
end
return self.nodes[bestNode]
end
--- Function to get valid neighbours of a node.
-- @param #ASTAR self
-- @param #ASTAR.Node theNode The node.
-- @param #table nodes Possible neighbours.
-- @param #table Valid neighbour nodes.
function ASTAR:_NeighbourNodes(theNode, nodes)
local neighbors = {}
for _,node in pairs(nodes) do
if theNode.id~=node.id then
local isvalid=self:_IsValidNeighbour(theNode, node)
if isvalid then
table.insert(neighbors, node)
end
end
end
return neighbors
end
--- Function to check if a node is not in a set.
-- @param #ASTAR self
-- @param #table set Set of nodes.
-- @param #ASTAR.Node theNode The node to check.
-- @return #boolean If true, the node is not in the set.
function ASTAR:_NotIn(set, theNode)
return set[theNode]==nil
end
--- Unwind path function.
-- @param #ASTAR self
-- @param #table flat_path Flat path.
-- @param #table map Map.
-- @param #ASTAR.Node current_node The current node.
-- @return #table Unwinded path.
function ASTAR:_UnwindPath( flat_path, map, current_node )
if map [current_node] then
table.insert (flat_path, 1, map[current_node])
return self:_UnwindPath(flat_path, map, map[current_node])
else
return flat_path
end
end
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