diff options
author | chai <215380520@qq.com> | 2024-05-23 10:08:29 +0800 |
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committer | chai <215380520@qq.com> | 2024-05-23 10:08:29 +0800 |
commit | 8722a9920c1f6119bf6e769cba270e63097f8e25 (patch) | |
tree | 2eaf9865de7fb1404546de4a4296553d8f68cc3b /Other/AstarPathfindingDemo/Packages/com.arongranberg.astar/Graphs/Nodes/TriangleMeshNode.cs | |
parent | 3ba4020b69e5971bb0df7ee08b31d10ea4d01937 (diff) |
+ astar project
Diffstat (limited to 'Other/AstarPathfindingDemo/Packages/com.arongranberg.astar/Graphs/Nodes/TriangleMeshNode.cs')
-rw-r--r-- | Other/AstarPathfindingDemo/Packages/com.arongranberg.astar/Graphs/Nodes/TriangleMeshNode.cs | 673 |
1 files changed, 673 insertions, 0 deletions
diff --git a/Other/AstarPathfindingDemo/Packages/com.arongranberg.astar/Graphs/Nodes/TriangleMeshNode.cs b/Other/AstarPathfindingDemo/Packages/com.arongranberg.astar/Graphs/Nodes/TriangleMeshNode.cs new file mode 100644 index 0000000..e7142a6 --- /dev/null +++ b/Other/AstarPathfindingDemo/Packages/com.arongranberg.astar/Graphs/Nodes/TriangleMeshNode.cs @@ -0,0 +1,673 @@ +#pragma warning disable 0162 +using UnityEngine; +using Pathfinding.Serialization; +using UnityEngine.Assertions; +using Unity.Mathematics; +using Pathfinding.Util; +using Unity.Burst; + +namespace Pathfinding { + /// <summary>Interface for something that holds a triangle based navmesh</summary> + public interface INavmeshHolder : ITransformedGraph, INavmesh { + /// <summary>Position of vertex number i in the world</summary> + Int3 GetVertex(int i); + + /// <summary> + /// Position of vertex number i in coordinates local to the graph. + /// The up direction is always the +Y axis for these coordinates. + /// </summary> + Int3 GetVertexInGraphSpace(int i); + + int GetVertexArrayIndex(int index); + + /// <summary>Transforms coordinates from graph space to world space</summary> + void GetTileCoordinates(int tileIndex, out int x, out int z); + } + + /// <summary>Node represented by a triangle</summary> + [Unity.Burst.BurstCompile] + // Sealing the class provides a nice performance boost (~5-10%) during pathfinding, because the JIT can inline more things and use non-virtual calls. + public sealed class TriangleMeshNode : MeshNode { + public TriangleMeshNode () { + HierarchicalNodeIndex = 0; + NodeIndex = DestroyedNodeIndex; + } + + public TriangleMeshNode (AstarPath astar) { + astar.InitializeNode(this); + } + + /// <summary> + /// Legacy compatibility. + /// Enabling this will make pathfinding use node centers, which leads to less accurate paths (but it's faster). + /// </summary> + public const bool InaccuratePathSearch = false; + internal override int PathNodeVariants => InaccuratePathSearch ? 1 : 3; + + /// <summary>Internal vertex index for the first vertex</summary> + public int v0; + + /// <summary>Internal vertex index for the second vertex</summary> + public int v1; + + /// <summary>Internal vertex index for the third vertex</summary> + public int v2; + + /// <summary>Holds INavmeshHolder references for all graph indices to be able to access them in a performant manner</summary> + static INavmeshHolder[] _navmeshHolders = new INavmeshHolder[0]; + + /// <summary>Used for synchronised access to the <see cref="_navmeshHolders"/> array</summary> + static readonly System.Object lockObject = new System.Object(); + + [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)] + public static INavmeshHolder GetNavmeshHolder (uint graphIndex) { + return _navmeshHolders[(int)graphIndex]; + } + + /// <summary> + /// Tile index in the recast or navmesh graph that this node is part of. + /// See: <see cref="NavmeshBase.GetTiles"/> + /// </summary> + public int TileIndex => (v0 >> NavmeshBase.TileIndexOffset) & NavmeshBase.TileIndexMask; + + /// <summary> + /// Sets the internal navmesh holder for a given graph index. + /// Warning: Internal method + /// </summary> + public static void SetNavmeshHolder (int graphIndex, INavmeshHolder graph) { + // We need to lock to make sure that + // the resize operation is thread safe + lock (lockObject) { + if (graphIndex >= _navmeshHolders.Length) { + var gg = new INavmeshHolder[graphIndex+1]; + _navmeshHolders.CopyTo(gg, 0); + _navmeshHolders = gg; + } + _navmeshHolders[graphIndex] = graph; + } + } + + public static void ClearNavmeshHolder (int graphIndex, INavmeshHolder graph) { + lock (lockObject) { + if (graphIndex < _navmeshHolders.Length && _navmeshHolders[graphIndex] == graph) { + _navmeshHolders[graphIndex] = null; + } + } + } + + /// <summary>Set the position of this node to the average of its 3 vertices</summary> + public void UpdatePositionFromVertices () { + Int3 a, b, c; + + GetVertices(out a, out b, out c); + position = (a + b + c) * 0.333333f; + } + + /// <summary> + /// Return a number identifying a vertex. + /// This number does not necessarily need to be a index in an array but two different vertices (in the same graph) should + /// not have the same vertex numbers. + /// </summary> + [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)] + public int GetVertexIndex (int i) { + return i == 0 ? v0 : (i == 1 ? v1 : v2); + } + + /// <summary> + /// Return a number specifying an index in the source vertex array. + /// The vertex array can for example be contained in a recast tile, or be a navmesh graph, that is graph dependant. + /// This is slower than GetVertexIndex, if you only need to compare vertices, use GetVertexIndex. + /// </summary> + public int GetVertexArrayIndex (int i) { + return GetNavmeshHolder(GraphIndex).GetVertexArrayIndex(i == 0 ? v0 : (i == 1 ? v1 : v2)); + } + + /// <summary>Returns all 3 vertices of this node in world space</summary> + public void GetVertices (out Int3 v0, out Int3 v1, out Int3 v2) { + // Get the object holding the vertex data for this node + // This is usually a graph or a recast graph tile + var holder = GetNavmeshHolder(GraphIndex); + + v0 = holder.GetVertex(this.v0); + v1 = holder.GetVertex(this.v1); + v2 = holder.GetVertex(this.v2); + } + + /// <summary>Returns all 3 vertices of this node in graph space</summary> + public void GetVerticesInGraphSpace (out Int3 v0, out Int3 v1, out Int3 v2) { + // Get the object holding the vertex data for this node + // This is usually a graph or a recast graph tile + var holder = GetNavmeshHolder(GraphIndex); + + v0 = holder.GetVertexInGraphSpace(this.v0); + v1 = holder.GetVertexInGraphSpace(this.v1); + v2 = holder.GetVertexInGraphSpace(this.v2); + } + + [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)] + public override Int3 GetVertex (int i) { + return GetNavmeshHolder(GraphIndex).GetVertex(GetVertexIndex(i)); + } + + public Int3 GetVertexInGraphSpace (int i) { + return GetNavmeshHolder(GraphIndex).GetVertexInGraphSpace(GetVertexIndex(i)); + } + + public override int GetVertexCount () { + // A triangle has 3 vertices + return 3; + } + + /// <summary> + /// Projects the given point onto the plane of this node's surface. + /// + /// The point will be projected down to a plane that contains the surface of the node. + /// If the point is not contained inside the node, it is projected down onto this plane anyway. + /// </summary> + public Vector3 ProjectOnSurface (Vector3 point) { + Int3 a, b, c; + + GetVertices(out a, out b, out c); + var pa = (Vector3)a; + var pb = (Vector3)b; + var pc = (Vector3)c; + var up = Vector3.Cross(pb-pa, pc-pa).normalized; + return point - up * Vector3.Dot(up, point-pa); + } + + public override Vector3 ClosestPointOnNode (Vector3 p) { + Int3 a, b, c; + + GetVertices(out a, out b, out c); + return Pathfinding.Polygon.ClosestPointOnTriangle((float3)(Vector3)a, (float3)(Vector3)b, (float3)(Vector3)c, (float3)p); + } + + /// <summary> + /// Closest point on the node when seen from above. + /// This method is mostly for internal use as the <see cref="Pathfinding.NavmeshBase.Linecast"/> methods use it. + /// + /// - The returned point is the closest one on the node to p when seen from above (relative to the graph). + /// This is important mostly for sloped surfaces. + /// - The returned point is an Int3 point in graph space. + /// - It is guaranteed to be inside the node, so if you call <see cref="ContainsPointInGraphSpace"/> with the return value from this method the result is guaranteed to be true. + /// + /// This method is slower than e.g <see cref="ClosestPointOnNode"/> or <see cref="ClosestPointOnNodeXZ"/>. + /// However they do not have the same guarantees as this method has. + /// </summary> + internal Int3 ClosestPointOnNodeXZInGraphSpace (Vector3 p) { + // Get the vertices that make up the triangle + Int3 a, b, c; + + GetVerticesInGraphSpace(out a, out b, out c); + + // Convert p to graph space + p = GetNavmeshHolder(GraphIndex).transform.InverseTransform(p); + + // Find the closest point on the triangle to p when looking at the triangle from above (relative to the graph) + var closest = Pathfinding.Polygon.ClosestPointOnTriangleXZ((Vector3)a, (Vector3)b, (Vector3)c, p); + + // Make sure the point is actually inside the node + var i3closest = (Int3)closest; + if (ContainsPointInGraphSpace(i3closest)) { + // Common case + return i3closest; + } else { + // Annoying... + // The closest point when converted from floating point coordinates to integer coordinates + // is not actually inside the node. It needs to be inside the node for some methods + // (like for example Linecast) to work properly. + + // Try the 8 integer coordinates around the closest point + // and check if any one of them are completely inside the node. + // This will most likely succeed as it should be very close. + for (int dx = -1; dx <= 1; dx++) { + for (int dz = -1; dz <= 1; dz++) { + if ((dx != 0 || dz != 0)) { + var candidate = new Int3(i3closest.x + dx, i3closest.y, i3closest.z + dz); + if (ContainsPointInGraphSpace(candidate)) return candidate; + } + } + } + + // Happens veery rarely. + // Pick the closest vertex of the triangle. + // The vertex is guaranteed to be inside the triangle. + var da = (a - i3closest).sqrMagnitudeLong; + var db = (b - i3closest).sqrMagnitudeLong; + var dc = (c - i3closest).sqrMagnitudeLong; + return da < db ? (da < dc ? a : c) : (db < dc ? b : c); + } + } + + public override Vector3 ClosestPointOnNodeXZ (Vector3 p) { + // Get all 3 vertices for this node + GetVertices(out Int3 tp1, out Int3 tp2, out Int3 tp3); + return Polygon.ClosestPointOnTriangleXZ((Vector3)tp1, (Vector3)tp2, (Vector3)tp3, p); + } + + /// <summary> + /// Checks if point is inside the node when seen from above. + /// + /// Note that <see cref="ContainsPointInGraphSpace"/> is faster than this method as it avoids + /// some coordinate transformations. If you are repeatedly calling this method + /// on many different nodes but with the same point then you should consider + /// transforming the point first and then calling ContainsPointInGraphSpace. + /// + /// <code> + /// Int3 p = (Int3)graph.transform.InverseTransform(point); + /// + /// node.ContainsPointInGraphSpace(p); + /// </code> + /// </summary> + public override bool ContainsPoint (Vector3 p) { + return ContainsPointInGraphSpace((Int3)GetNavmeshHolder(GraphIndex).transform.InverseTransform(p)); + } + + /// <summary>Checks if point is inside the node when seen from above, as defined by the movement plane</summary> + public bool ContainsPoint (Vector3 p, NativeMovementPlane movementPlane) { + // Get all 3 vertices for this node + GetVertices(out var a, out var b, out var c); + var pa = (int3)a; + var pb = (int3)b; + var pc = (int3)c; + var pp = (int3)(Int3)p; + return Polygon.ContainsPoint(ref pa, ref pb, ref pc, ref pp, ref movementPlane); + } + + /// <summary> + /// Checks if point is inside the node in graph space. + /// + /// In graph space the up direction is always the Y axis so in principle + /// we project the triangle down on the XZ plane and check if the point is inside the 2D triangle there. + /// </summary> + public override bool ContainsPointInGraphSpace (Int3 p) { + // Get all 3 vertices for this node + GetVerticesInGraphSpace(out var a, out var b, out var c); + + if ((long)(b.x - a.x) * (long)(p.z - a.z) - (long)(p.x - a.x) * (long)(b.z - a.z) > 0) return false; + + if ((long)(c.x - b.x) * (long)(p.z - b.z) - (long)(p.x - b.x) * (long)(c.z - b.z) > 0) return false; + + if ((long)(a.x - c.x) * (long)(p.z - c.z) - (long)(p.x - c.x) * (long)(a.z - c.z) > 0) return false; + + return true; + // Equivalent code, but the above code is faster + //return Polygon.IsClockwiseMargin (a,b, p) && Polygon.IsClockwiseMargin (b,c, p) && Polygon.IsClockwiseMargin (c,a, p); + + //return Polygon.ContainsPoint(g.GetVertex(v0),g.GetVertex(v1),g.GetVertex(v2),p); + } + + public static readonly Unity.Profiling.ProfilerMarker MarkerDecode = new Unity.Profiling.ProfilerMarker("Decode"); + public static readonly Unity.Profiling.ProfilerMarker MarkerGetVertices = new Unity.Profiling.ProfilerMarker("GetVertex"); + public static readonly Unity.Profiling.ProfilerMarker MarkerClosest = new Unity.Profiling.ProfilerMarker("MarkerClosest"); + + public override Int3 DecodeVariantPosition (uint pathNodeIndex, uint fractionAlongEdge) { + var edge = (int)(pathNodeIndex - NodeIndex); + var p1 = GetVertex(edge); + var p2 = GetVertex((edge + 1) % 3); + InterpolateEdge(ref p1, ref p2, fractionAlongEdge, out var pos); + return pos; + } + + [BurstCompile(FloatMode = FloatMode.Fast)] + static void InterpolateEdge (ref Int3 p1, ref Int3 p2, uint fractionAlongEdge, out Int3 pos) { + var p = (int3)math.lerp((float3)(int3)p1, (float3)(int3)p2, PathNode.UnQuantizeFractionAlongEdge(fractionAlongEdge)); + pos = new Int3(p.x, p.y, p.z); + } + + public override void OpenAtPoint (Path path, uint pathNodeIndex, Int3 point, uint gScore) { + if (InaccuratePathSearch) { + Open(path, pathNodeIndex, gScore); + } else { + OpenAtPoint(path, pathNodeIndex, point, -1, gScore); + } + } + + public override void Open (Path path, uint pathNodeIndex, uint gScore) { + var pathHandler = (path as IPathInternals).PathHandler; + if (InaccuratePathSearch) { + var pn = pathHandler.pathNodes[pathNodeIndex]; + if (pn.flag1) path.OpenCandidateConnectionsToEndNode(position, pathNodeIndex, NodeIndex, gScore); + + if (connections != null) { + // Iterate over all adjacent nodes + for (int i = connections.Length-1; i >= 0; i--) { + var conn = connections[i]; + var other = conn.node; + if (conn.isOutgoing && other.NodeIndex != pn.parentIndex) { + path.OpenCandidateConnection(pathNodeIndex, other.NodeIndex, gScore, conn.cost + path.GetTraversalCost(other), 0, other.position); + } + } + } + return; + } + // One path node variant is created for each side of the triangle + // This particular path node represents just one of the sides of the triangle. + var edge = (int)(pathNodeIndex - NodeIndex); + OpenAtPoint(path, pathNodeIndex, DecodeVariantPosition(pathNodeIndex, pathHandler.pathNodes[pathNodeIndex].fractionAlongEdge), edge, gScore); + } + + void OpenAtPoint (Path path, uint pathNodeIndex, Int3 pos, int edge, uint gScore) { + var pathHandler = (path as IPathInternals).PathHandler; + var pn = pathHandler.pathNodes[pathNodeIndex]; + if (pn.flag1) path.OpenCandidateConnectionsToEndNode(pos, pathNodeIndex, NodeIndex, gScore); + int visitedEdges = 0; + bool cameFromOtherEdgeInThisTriangle = pn.parentIndex >= NodeIndex && pn.parentIndex < NodeIndex + 3; + + if (connections != null) { + // Iterate over all adjacent nodes + for (int i = connections.Length-1; i >= 0; i--) { + var conn = connections[i]; + if (!conn.isOutgoing) continue; + var other = conn.node; + + // Check if we are moving from a side of this triangle, to the corresponding side on an adjacent triangle. + if (conn.isEdgeShared) { + var sharedEdgeOnOtherNode = conn.adjacentShapeEdge; + var adjacentPathNodeIndex = other.NodeIndex + (uint)sharedEdgeOnOtherNode; + + // Skip checking our parent node. This is purely a performance optimization. + if (adjacentPathNodeIndex == pn.parentIndex) continue; + + if (conn.shapeEdge == edge) { + // Make sure we can traverse the neighbour + if (path.CanTraverse(this, other)) { + var tOther = other as TriangleMeshNode; + + // Fast path out if we know we have already searched this node and we cannot improve it + if (!path.ShouldConsiderPathNode(adjacentPathNodeIndex)) { + continue; + } + + if (conn.edgesAreIdentical) { + // The edge on the other node is identical to this edge (but reversed). + // This means that no other node can reach the other node through that edge. + // This is great, because we can then skip adding that node to the heap just + // to immediatelly pop it again. This is a performance optimization. + + var otherEnteringCost = path.GetTraversalCost(other); + ref var otherPathNode = ref pathHandler.pathNodes[adjacentPathNodeIndex]; + otherPathNode.pathID = path.pathID; + otherPathNode.heapIndex = BinaryHeap.NotInHeap; + otherPathNode.parentIndex = pathNodeIndex; + otherPathNode.fractionAlongEdge = PathNode.ReverseFractionAlongEdge(pn.fractionAlongEdge); + // Make sure the path gets information about us having visited this in-between node, + // even if we never add it to the heap + path.OnVisitNode(adjacentPathNodeIndex, uint.MaxValue, gScore + otherEnteringCost); + pathHandler.LogVisitedNode(adjacentPathNodeIndex, uint.MaxValue, gScore + otherEnteringCost); + + tOther.OpenAtPoint(path, adjacentPathNodeIndex, pos, sharedEdgeOnOtherNode, gScore + otherEnteringCost); + } else { + OpenSingleEdge(path, pathNodeIndex, tOther, sharedEdgeOnOtherNode, pos, gScore); + } + } + } else { + // The other node is a node which shares a different edge with this node. + // We will consider this connection at another time. + + // However, we will consider the move to another side of this triangle, + // namely to the side that *is* shared with the other node. + // If a side of this triangle doesn't share an edge with any connection, we will + // not bother searching it (we will not reach this part of the code), because + // we know its a dead end. + + // If we came from another side of this triangle, it is completely redundant to try to move back to + // another edge in this triangle, because we could always have reached it faster from the parent. + // We also make sure we don't attempt to move to the same edge twice, as that's just a waste of time. + if (!cameFromOtherEdgeInThisTriangle && (visitedEdges & (1 << conn.shapeEdge)) == 0) { + visitedEdges |= 1 << conn.shapeEdge; + OpenSingleEdge(path, pathNodeIndex, this, conn.shapeEdge, pos, gScore); + } + } + } else if (!cameFromOtherEdgeInThisTriangle) { + // This is a connection to some other node type, most likely. For example an off-mesh link. + if (path.CanTraverse(this, other) && path.ShouldConsiderPathNode(other.NodeIndex)) { + var cost = (uint)(other.position - pos).costMagnitude; + + if (edge != -1) { + // We are moving from an edge of this triangle + path.OpenCandidateConnection(pathNodeIndex, other.NodeIndex, gScore, cost, 0, other.position); + } else { + // In some situations we may be moving directly from one off-mesh link to another one without + // passing through any concrete nodes in between. In this case we need to create a temporary node + // to allow the correct path to be reconstructed later. The only important part of the temporary + // node is that we save this node as the associated node. + // This is somewhat ugly, and it limits the number of times we can encounter this case during + // a single search (there's a limit to the number of temporary nodes we can have at the same time). + // Fortunately, this case only happens if there is more than 1 off-mesh link connected to a single + // node, which is quite rare in most games. + // In this case, pathNodeIndex will be another node's index, not a path node belonging to this node. + var viaNode = pathHandler.AddTemporaryNode(new TemporaryNode { + associatedNode = NodeIndex, + position = pos, + targetIndex = 0, + type = TemporaryNodeType.Ignore, + }); + ref var viaPathNode = ref pathHandler.pathNodes[viaNode]; + viaPathNode.pathID = path.pathID; + viaPathNode.parentIndex = pathNodeIndex; + path.OpenCandidateConnection(viaNode, other.NodeIndex, gScore, cost, 0, other.position); + } + } + } + } + } + } + + void OpenSingleEdge (Path path, uint pathNodeIndex, TriangleMeshNode other, int sharedEdgeOnOtherNode, Int3 pos, uint gScore) { + var adjacentPathNodeIndex = other.NodeIndex + (uint)sharedEdgeOnOtherNode; + + // Fast path out if we know we have already searched this node and we cannot improve it + if (!path.ShouldConsiderPathNode(adjacentPathNodeIndex)) { + return; + } + + var s1 = other.GetVertex(sharedEdgeOnOtherNode); + var s2 = other.GetVertex((sharedEdgeOnOtherNode + 1) % 3); + + var pathHandler = (path as IPathInternals).PathHandler; + // TODO: Incorrect, counts nodes multiple times + var otherEnteringCost = path.GetTraversalCost(other); + + var candidateG = gScore + otherEnteringCost; + + OpenSingleEdgeBurst( + ref s1, + ref s2, + ref pos, + path.pathID, + pathNodeIndex, + adjacentPathNodeIndex, + other.NodeIndex, + candidateG, + ref pathHandler.pathNodes, + ref pathHandler.heap, + ref path.heuristicObjectiveInternal + ); + } + + [Unity.Burst.BurstCompile] + static void OpenSingleEdgeBurst (ref Int3 s1, ref Int3 s2, ref Int3 pos, ushort pathID, uint pathNodeIndex, uint candidatePathNodeIndex, uint candidateNodeIndex, uint candidateG, ref UnsafeSpan<PathNode> pathNodes, ref BinaryHeap heap, ref HeuristicObjective heuristicObjective) { + CalculateBestEdgePosition(ref s1, ref s2, ref pos, out var closestPointAlongEdge, out var quantizedFractionAlongEdge, out var cost); + candidateG += cost; + + var pars = new Path.OpenCandidateParams { + pathID = pathID, + parentPathNode = pathNodeIndex, + targetPathNode = candidatePathNodeIndex, + targetNodeIndex = candidateNodeIndex, + candidateG = candidateG, + fractionAlongEdge = quantizedFractionAlongEdge, + targetNodePosition = closestPointAlongEdge, + pathNodes = pathNodes, + }; + Path.OpenCandidateConnectionBurst(ref pars, ref heap, ref heuristicObjective); + } + + [Unity.Burst.BurstCompile] + static void CalculateBestEdgePosition (ref Int3 s1, ref Int3 s2, ref Int3 pos, out int3 closestPointAlongEdge, out uint quantizedFractionAlongEdge, out uint cost) { + // Find the closest point on the other edge. From here on, we will let the position of that path node be this closest point. + // This is much better than using the edge midpoint, and also better than any interpolation between closestFractionAlongEdge + // and the midpoint (0.5). + // In my tests, using the edge midpoint leads to path costs that are rougly 1.3-1.6 times greater than the real distance, + // but using the closest point leads to path costs that are only 1.1-1.2 times greater than the real distance. + // Using triangle centers is the worst option, it leads to path costs that are roughly 1.6-2.0 times greater than the real distance. + // Triangle centers were always used before version 4.3.67. + var v1 = (float3)(int3)s1; + var v2 = (float3)(int3)s2; + var posi = (int3)pos; + var closestFractionAlongEdge = math.clamp(VectorMath.ClosestPointOnLineFactor(v1, v2, (float3)posi), 0, 1); + quantizedFractionAlongEdge = PathNode.QuantizeFractionAlongEdge(closestFractionAlongEdge); + closestFractionAlongEdge = PathNode.UnQuantizeFractionAlongEdge(quantizedFractionAlongEdge); + var closestPointAlongEdgeV = math.lerp(v1, v2, closestFractionAlongEdge); + closestPointAlongEdge = (int3)closestPointAlongEdgeV; + + var diff = posi - closestPointAlongEdge; + cost = (uint)new Int3(diff.x, diff.y, diff.z).costMagnitude; + } + + /// <summary> + /// Returns the edge which is shared with other. + /// + /// If there is no shared edge between the two nodes, then -1 is returned. + /// + /// The vertices in the edge can be retrieved using + /// <code> + /// var edge = node.SharedEdge(other); + /// var a = node.GetVertex(edge); + /// var b = node.GetVertex((edge+1) % node.GetVertexCount()); + /// </code> + /// + /// See: <see cref="GetPortal"/> which also handles edges that are shared over tile borders and some types of node links + /// </summary> + public int SharedEdge (GraphNode other) { + var edge = -1; + + if (connections != null) { + for (int i = 0; i < connections.Length; i++) { + if (connections[i].node == other && connections[i].isEdgeShared) edge = connections[i].shapeEdge; + } + } + return edge; + } + + public override bool GetPortal (GraphNode toNode, out Vector3 left, out Vector3 right) { + return GetPortal(toNode, out left, out right, out _, out _); + } + + public bool GetPortalInGraphSpace (TriangleMeshNode toNode, out Int3 a, out Int3 b, out int aIndex, out int bIndex) { + aIndex = -1; + bIndex = -1; + a = Int3.zero; + b = Int3.zero; + + // If the nodes are in different graphs, this function has no idea on how to find a shared edge. + if (toNode.GraphIndex != GraphIndex) return false; + + int edge = -1; + int otherEdge = -1; + if (connections != null) { + for (int i = 0; i < connections.Length; i++) { + if (connections[i].node == toNode && connections[i].isEdgeShared) { + edge = connections[i].shapeEdge; + otherEdge = connections[i].adjacentShapeEdge; + } + } + } + + // -1: No connection was found between the nodes + if (edge == -1) return false; + + aIndex = edge; + bIndex = (edge + 1) % 3; + + // Get the vertices of the shared edge for the first node + var graph = GetNavmeshHolder(GraphIndex); + a = graph.GetVertexInGraphSpace(GetVertexIndex(aIndex)); + b = graph.GetVertexInGraphSpace(GetVertexIndex(bIndex)); + + // Get tiles the nodes are contained in + int tileIndex1 = TileIndex; + int tileIndex2 = toNode.TileIndex; + + if (tileIndex1 != tileIndex2) { + // When the nodes are in different tiles, the edges may not be completely identical + // so another technique is needed. + + // When the nodes are in different tiles, they might not share exactly the same edge + // so we clamp the portal to the segment of the edges which they both have.. + + // Get the vertices of the shared edge for the second node + Int3 v2a = toNode.GetVertexInGraphSpace(otherEdge); + Int3 v2b = toNode.GetVertexInGraphSpace((otherEdge+1) % 3); + graph.GetTileCoordinates(tileIndex1, out var tileX1, out var tileZ1); + graph.GetTileCoordinates(tileIndex2, out var tileX2, out var tileZ2); + var axis = tileX1 == tileX2 ? 0 : 2; + Assert.IsTrue(axis == 0 ? tileX1 == tileX2 : tileZ1 == tileZ2); + // This tile-edge aligned coordinate of the vertices should ideally be identical. + // But somewhere in the pipeline some errors may crop up, and thus they may be off by one. + // TODO: Fix this. + Assert.IsTrue(Mathf.Abs(a[2 - axis] - b[2 - axis]) <= 1); + var mn = Mathf.Min(v2a[axis], v2b[axis]); + var mx = Mathf.Max(v2a[axis], v2b[axis]); + + a[axis] = Mathf.Clamp(a[axis], mn, mx); + b[axis] = Mathf.Clamp(b[axis], mn, mx); + } + + return true; + } + + public bool GetPortal (GraphNode toNode, out Vector3 left, out Vector3 right, out int aIndex, out int bIndex) { + if (toNode is TriangleMeshNode toTriNode && GetPortalInGraphSpace(toTriNode, out var a, out var b, out aIndex, out bIndex)) { + var graph = GetNavmeshHolder(GraphIndex); + // All triangles should be laid out in clockwise order so b is the rightmost vertex (seen from this node) + left = graph.transform.Transform((Vector3)a); + right = graph.transform.Transform((Vector3)b); + return true; + } else { + aIndex = -1; + bIndex = -1; + left = Vector3.zero; + right = Vector3.zero; + return false; + } + } + + /// <summary>TODO: This is the area in XZ space, use full 3D space for higher correctness maybe?</summary> + public override float SurfaceArea () { + var holder = GetNavmeshHolder(GraphIndex); + + return System.Math.Abs(VectorMath.SignedTriangleAreaTimes2XZ(holder.GetVertex(v0), holder.GetVertex(v1), holder.GetVertex(v2))) * 0.5f; + } + + public override Vector3 RandomPointOnSurface () { + // Find a random point inside the triangle + // This generates uniformly distributed trilinear coordinates + // See http://mathworld.wolfram.com/TrianglePointPicking.html + float2 r; + + do { + r = AstarMath.ThreadSafeRandomFloat2(); + } while (r.x+r.y > 1); + + // Pick the point corresponding to the trilinear coordinate + GetVertices(out var v0, out var v1, out var v2); + return ((Vector3)(v1-v0))*r.x + ((Vector3)(v2-v0))*r.y + (Vector3)v0; + } + + public override void SerializeNode (GraphSerializationContext ctx) { + base.SerializeNode(ctx); + ctx.writer.Write(v0); + ctx.writer.Write(v1); + ctx.writer.Write(v2); + } + + public override void DeserializeNode (GraphSerializationContext ctx) { + base.DeserializeNode(ctx); + v0 = ctx.reader.ReadInt32(); + v1 = ctx.reader.ReadInt32(); + v2 = ctx.reader.ReadInt32(); + } + } +} |