1 files changed, 82 insertions, 0 deletions
diff --git a/Other/AstarPathfindingDemo/Packages/com.arongranberg.astar/ExampleScenes/Scenes/OldExamples/Example18_RTS/RTSBuildingManager.cs b/Other/AstarPathfindingDemo/Packages/com.arongranberg.astar/ExampleScenes/Scenes/OldExamples/Example18_RTS/RTSBuildingManager.cs
new file mode 100644
index 0000000..87e5cd7
--- /dev/null
+++ b/Other/AstarPathfindingDemo/Packages/com.arongranberg.astar/ExampleScenes/Scenes/OldExamples/Example18_RTS/RTSBuildingManager.cs
@@ -0,0 +1,82 @@
+using UnityEngine;
+using System.Collections.Generic;
+using Pathfinding;
+using System.Linq;
+
+namespace Pathfinding.Examples.RTS {
+	[HelpURL("https://arongranberg.com/astar/documentation/stable/rtsbuildingmanager.html")]
+	public class RTSBuildingManager : MonoBehaviour {
+		public static bool IsValidBuildingPlacement (GameObject building) {
+			var onNavmesh = AstarPath.active.data.recastGraph.PointOnNavmesh(building.transform.position, NNConstraint.None);
+
+			// Check if the center of the building is on the navmesh
+			if (onNavmesh == null) return false;
+
+			var cuts = building.GetComponentsInChildren<NavmeshCut>(true);
+			if (cuts.Length == 0) return true;
+
+			var graph = AstarPath.active.data.recastGraph;
+			var characterRadius = graph.characterRadius;
+			var boundingBox = cuts[0].GetBounds(graph.transform, characterRadius);
+			List<NavmeshCut.Contour> contours = new List<NavmeshCut.Contour>();
+			for (int i = 0; i < cuts.Length; i++) {
+				boundingBox = RectUnion(boundingBox, cuts[i].GetBounds(graph.transform, characterRadius));
+				cuts[i].GetContour(contours, Matrix4x4.identity, characterRadius);
+			}
+
+			Vector2[][] contourArrays = contours.Select(c => c.contour.ToArray()).ToArray();
+
+			// Loop over all tiles in the vincinity of the building
+			var touchingTiles = graph.GetTouchingTilesInGraphSpace(boundingBox);
+			for (int x = touchingTiles.xmin; x <= touchingTiles.xmax; x++) {
+				for (int z = touchingTiles.ymin; z <= touchingTiles.ymax; z++) {
+					// Loop over all nodes in the tile
+					var tile = graph.GetTile(x, z);
+					for (int i = 0; i < tile.nodes.Length; i++) {
+						// Figure out which sides of the node are shared with adjacent nodes
+						// and which ones are graph borders.
+						var node = tile.nodes[i];
+						var usedSides = new bool[3];
+						for (int j = 0; j < node.connections.Length; j++) {
+							var conn = node.connections[j];
+							if (conn.isEdgeShared && conn.shapeEdge >= 0 && conn.shapeEdge < 3) usedSides[conn.shapeEdge] = true;
+						}
+
+						for (int j = 0; j < 3; j++) {
+							if (!usedSides[j]) {
+								// This is a graph border as it is not shared with any neighbour nodes.
+								// Check if this segment intersects with any navmesh cuts of the building
+
+								var segmentStart = (Vector3)node.GetVertex(j);
+								var segmentEnd = (Vector3)node.GetVertex((j+1) % 3);
+
+								for (int k = 0; k < contourArrays.Length; k++) {
+									if (Polygon.ContainsPoint(contourArrays[k], new Vector2(segmentStart.x, segmentStart.z)) || Polygon.ContainsPoint(contourArrays[k], new Vector2(segmentEnd.x, segmentEnd.z))) {
+										// One of the vertices of the segment was inside a navmesh cut! This means the building placement is invalid
+										return false;
+									}
+
+									var contour = contourArrays[k];
+									for (int v = 0; v < contour.Length; v++) {
+										var a = new Vector3(contour[v].x, 0.0f, contour[v].y);
+										var b = new Vector3(contour[(v+1) % contour.Length].x, 0.0f, contour[(v+1) % contour.Length].y);
+										if (VectorMath.SegmentsIntersectXZ(a, b, segmentStart, segmentEnd)) {
+											// This segment intersects one of the segments of a navmesh cut! This means the building placement is invalid
+											return false;
+										}
+									}
+								}
+							}
+						}
+					}
+				}
+			}
+
+			return true;
+		}
+
+		static Rect RectUnion (Rect a, Rect b) {
+			return Rect.MinMaxRect(Mathf.Min(a.xMin, b.xMin), Mathf.Min(a.yMin, b.yMin), Mathf.Max(a.xMax, b.xMax), Mathf.Max(a.yMax, b.yMax));
+		}
+	}
+}