PathFinder got some big changes (PathSearch)

This commit is contained in:
Bob
2009-11-08 16:51:44 +13:00
parent 8ae3c04212
commit 267e96f04c
5 changed files with 211 additions and 179 deletions

View File

@@ -27,22 +27,6 @@ namespace OpenRa.Game
: float.PositiveInfinity;
}
public List<int2> FindUnitPath(int2 src, int2 dest, UnitMovementType umt)
{
using (new PerfSample("find_unit_path"))
return FindUnitPath(src, DefaultEstimator(dest), umt);
}
public List<int2> FindUnitPathToRange(int2 src, int2 dest, UnitMovementType umt, int range)
{
var tilesInRange = Game.FindTilesInCircle(dest, range)
.Where(t => Game.IsCellBuildable(t, umt));
var path = FindUnitPath(tilesInRange, DefaultEstimator(src), umt);
path.Reverse();
return path;
}
bool IsBlocked(int2 from, UnitMovementType umt)
{
for (int v = -1; v < 2; v++)
@@ -57,103 +41,63 @@ namespace OpenRa.Game
return true;
}
public List<int2> FindUnitPath( int2 from, int2 target, UnitMovementType umt )
{
using( new PerfSample( "find_unit_path" ) )
return FindPath( PathSearch.FromPoint( from, target, umt, false ) );
}
public List<int2> FindUnitPathToRange( int2 src, int2 target, UnitMovementType umt, int range )
{
using( new PerfSample( "find_unit_path_multiple_src" ) )
{
var tilesInRange = Game.FindTilesInCircle( src, range )
.Where( t => Game.IsCellBuildable( t, umt ) );
var path = FindPath( PathSearch.FromPoints( tilesInRange, target, umt, false ));
path.Reverse();
return path;
}
}
public List<int2> FindPathToPath( int2 from, List<int2> path, UnitMovementType umt )
{
using (new PerfSample("find_path_to_path"))
{
if (IsBlocked(from, umt))
return new List<int2>();
if( IsBlocked( from, umt ) )
return new List<int2>();
CellInfo[,] cellInfo = null;
var queue = new PriorityQueue<PathDistance>();
var estimator = DefaultEstimator(from);
var cost = 0.0f;
var prev = path[0];
for (int i = 0; i < path.Count; i++)
{
var sl = path[i];
if ( /*i == 0 || */(Game.BuildingInfluence.CanMoveHere(path[i]) && Game.UnitInfluence.GetUnitAt(path[i]) == null))
{
queue.Add(new PathDistance(estimator(sl), sl));
if (cellInfo == null)
cellInfo = InitCellInfo();
cellInfo[sl.X, sl.Y] = new CellInfo(cost, prev, false);
}
var d = sl - prev;
cost += ((d.X * d.Y != 0) ? 1.414213563f : 1.0f) * passableCost[(int)umt][sl.X, sl.Y];
prev = sl;
}
if (queue.Empty) return new List<int2>();
var h2 = DefaultEstimator(path[0]);
var otherQueue = new PriorityQueue<PathDistance>();
otherQueue.Add(new PathDistance(h2(from), from));
var otherCellInfo = InitCellInfo();
otherCellInfo[from.X, from.Y] = new CellInfo( 0, from, false );
var ret = FindBidiPath(cellInfo, otherCellInfo, queue, otherQueue, estimator, h2, umt, true);
return ret;
}
using( new PerfSample( "find_path_to_path" ) )
return FindBidiPath(
PathSearch.FromPath( path, from, umt, true ),
PathSearch.FromPoint( from, path[ 0 ], umt, true ) );
}
public List<int2> FindUnitPath( int2 unitLocation, Func<int2,float> estimator, UnitMovementType umt )
{
return FindUnitPath( new[] { unitLocation }, estimator, umt );
}
public List<int2> FindUnitPath( IEnumerable<int2> startLocations, Func<int2, float> estimator, UnitMovementType umt )
{
var cellInfo = InitCellInfo();
var queue = new PriorityQueue<PathDistance>();
foreach (var sl in startLocations)
{
queue.Add(new PathDistance(estimator(sl), sl));
cellInfo[sl.X, sl.Y].MinCost = 0;
}
return FindPath( cellInfo, queue, estimator, umt, false );
}
List<int2> FindPath( CellInfo[ , ] cellInfo, PriorityQueue<PathDistance> queue, Func<int2, float> estimator, UnitMovementType umt, bool checkForBlock )
public List<int2> FindPath( PathSearch search )
{
int nodesExpanded = 0;
using (new PerfSample("find_path_inner"))
{
while (!queue.Empty)
while (!search.queue.Empty)
{
PathDistance p = queue.Pop();
cellInfo[p.Location.X, p.Location.Y].Seen = true;
var p = search.Expand( passableCost );
if (estimator(p.Location) == 0)
if (search.heuristic(p) == 0)
{
PerfHistory.Increment("nodes_expanded", nodesExpanded * .01);
return MakePath(cellInfo, p.Location);
return MakePath(search.cellInfo, p);
}
nodesExpanded++;
ExpandNode(cellInfo, queue, p, umt, checkForBlock, estimator);
PerfHistory.Increment( "nodes_expanded", nodesExpanded * .01 );
}
PerfHistory.Increment("nodes_expanded", nodesExpanded * .01);
// no path exists
return new List<int2>();
}
}
static CellInfo[ , ] InitCellInfo()
{
var cellInfo = new CellInfo[ 128, 128 ];
for( int x = 0 ; x < 128 ; x++ )
for( int y = 0 ; y < 128 ; y++ )
cellInfo[ x, y ] = new CellInfo( float.PositiveInfinity, new int2( x, y ), false );
return cellInfo;
}
List<int2> MakePath( CellInfo[ , ] cellInfo, int2 destination )
static List<int2> MakePath( CellInfo[ , ] cellInfo, int2 destination )
{
List<int2> ret = new List<int2>();
int2 pathNode = destination;
@@ -165,112 +109,60 @@ namespace OpenRa.Game
}
ret.Add(pathNode);
CheckSanePath(ret);
return ret;
}
static Func<int2, float> DefaultEstimator(int2 destination)
{
return here =>
{
int2 d = ( here - destination ).Abs();
int diag = Math.Min( d.X, d.Y );
int straight = Math.Abs( d.X - d.Y );
return 1.5f * diag + straight;
};
}
void ExpandNode(CellInfo[,] ci, PriorityQueue<PathDistance> q, PathDistance p, UnitMovementType umt, bool checkForBlock, Func<int2, float> h)
{
foreach (int2 d in Util.directions)
{
int2 newHere = p.Location + d;
if (ci[newHere.X, newHere.Y].Seen)
continue;
if (passableCost[(int)umt][newHere.X, newHere.Y] == float.PositiveInfinity)
continue;
if (!Game.BuildingInfluence.CanMoveHere(newHere))
continue;
if (checkForBlock && Game.UnitInfluence.GetUnitAt(newHere) != null)
continue;
var est = h(newHere);
if (est == float.PositiveInfinity)
continue;
float cellCost = ((d.X * d.Y != 0) ? 1.414213563f : 1.0f) * passableCost[(int)umt][newHere.X, newHere.Y];
float newCost = ci[p.Location.X, p.Location.Y].MinCost + cellCost;
if (newCost >= ci[newHere.X, newHere.Y].MinCost)
continue;
ci[newHere.X, newHere.Y].Path = p.Location;
ci[newHere.X, newHere.Y].MinCost = newCost;
q.Add(new PathDistance(newCost + est, newHere));
}
}
List<int2> FindBidiPath( /* searches from both ends toward each other */
CellInfo[,] ca,
CellInfo[,] cb,
PriorityQueue<PathDistance> qa,
PriorityQueue<PathDistance> qb,
Func<int2, float> ha,
Func<int2, float> hb,
UnitMovementType umt,
bool checkForBlocked)
PathSearch fromSrc,
PathSearch fromDest)
{
while (!qa.Empty && !qb.Empty)
while (!fromSrc.queue.Empty && !fromDest.queue.Empty)
{
{ /* make some progress on the first search */
var p = qa.Pop();
ca[p.Location.X, p.Location.Y].Seen = true;
/* make some progress on the first search */
var p = fromSrc.Expand( passableCost );
if (fromDest.cellInfo[p.X, p.Y].MinCost < float.PositiveInfinity)
return MakeBidiPath(fromSrc, fromDest, p);
if (cb[p.Location.X, p.Location.Y].MinCost < float.PositiveInfinity)
return MakeBidiPath(ca, cb, p.Location);
else
ExpandNode(ca, qa, p, umt, checkForBlocked, ha);
}
{ /* make some progress on the second search */
var p = qb.Pop();
cb[p.Location.X, p.Location.Y].Seen = true;
//if (ca[p.Location.X, p.Location.Y].MinCost < float.PositiveInfinity)
// return MakeBidiPath(ca, cb, p.Location);
//else
ExpandNode(cb, qb, p, umt, checkForBlocked, hb);
}
/* make some progress on the second search */
fromDest.Expand( passableCost );
}
return new List<int2>();
}
static List<int2> MakeBidiPath(CellInfo[,] ca, CellInfo[,] cb, int2 p)
static List<int2> MakeBidiPath(PathSearch a, PathSearch b, int2 p)
{
var a = new List<int2>();
var ca = a.cellInfo;
var cb = b.cellInfo;
var ret = new List<int2>();
var q = p;
while (ca[q.X, q.Y].Path != q)
{
a.Add( q );
ret.Add( q );
q = ca[ q.X, q.Y ].Path;
}
a.Reverse();
ret.Reverse();
q = p;
while (cb[q.X, q.Y].Path != q)
{
q = cb[q.X, q.Y].Path;
a.Add(q);
ret.Add(q);
}
CheckSanePath( a );
return a;
CheckSanePath( ret );
return ret;
}
[System.Diagnostics.Conditional( "SANITY_CHECKS" )]
static void CheckSanePath( List<int2> path )
{