/// <summary>Creates a new instance of PathFinder.</summary> /// <param name="numRows">The number of rows in the grid.</param> /// <param name="numCols">The number of columns in the grid.</param> /// <param name="inWorld">The world that contains this path finder.</param> public PathFinder(int numRows, int numCols, World inWorld) { clear(); InWorld = inWorld; Grid = new PathNode[numRows, numCols]; Nodes = new PathNode[numRows * numCols]; NodeSpacing = (VectorD)inWorld.Size / new VectorD((double)numCols, (double)numRows); // build grid PathNode node = null; // temporary variable // initialize each node in the grid for (int row = 0; row < numRows; row++) { for (int col = 0; col < numCols; col++) { node = new PathNode(); node.Index = row * NumCols + col; node.Position = new VectorD((double)col * NodeSpacing.X, (double)row * NodeSpacing.Y); Grid[row, col] = node; Nodes[node.Index] = node; } } // connect nodes to each other, if not blocked for (int row = 0; row < numRows; row++) { for (int col = 0; col < numCols; col++) { // use collision detection to rule out connections (only geos can block) node = Grid[row, col]; PathNode destNode = null; VectorF nodePos = (VectorF)node.Position; if (col < numCols - 1) { // upper-right if (row > 0) { destNode = Grid[row - 1, col + 1]; if (!inWorld.Collision.segCollision(nodePos, (VectorF)destNode.Position, null, null, false, false, true)) { node.addLast(new PathEdge(this, node.Index, destNode.Index)); destNode.addLast(new PathEdge(this, destNode.Index, node.Index)); } } // right destNode = Grid[row, col + 1]; if (!inWorld.Collision.segCollision(nodePos, (VectorF)destNode.Position, null, null, false, false, true)) { node.addLast(new PathEdge(this, node.Index, destNode.Index)); destNode.addLast(new PathEdge(this, destNode.Index, node.Index)); } // lower right if (row < numRows - 1) { destNode = Grid[row + 1, col + 1]; if (!inWorld.Collision.segCollision(nodePos, (VectorF)destNode.Position, null, null, false, false, true)) { node.addLast(new PathEdge(this, node.Index, destNode.Index)); destNode.addLast(new PathEdge(this, destNode.Index, node.Index)); } } } // bottom if (row < numRows - 1) { destNode = Grid[row + 1, col]; if (!inWorld.Collision.segCollision(nodePos, (VectorF)destNode.Position, null, null, false, false, true)) { node.addLast(new PathEdge(this, node.Index, destNode.Index)); destNode.addLast(new PathEdge(this, destNode.Index, node.Index)); } } } } }