From 8722a9920c1f6119bf6e769cba270e63097f8e25 Mon Sep 17 00:00:00 2001
From: chai <215380520@qq.com>
Date: Thu, 23 May 2024 10:08:29 +0800
Subject: + astar project

---
 .../OldExamples/Example13_Moving/BezierMover.cs    | 96 ++++++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 Other/AstarPathfindingDemo/Packages/com.arongranberg.astar/ExampleScenes/Scenes/OldExamples/Example13_Moving/BezierMover.cs

(limited to 'Other/AstarPathfindingDemo/Packages/com.arongranberg.astar/ExampleScenes/Scenes/OldExamples/Example13_Moving/BezierMover.cs')

diff --git a/Other/AstarPathfindingDemo/Packages/com.arongranberg.astar/ExampleScenes/Scenes/OldExamples/Example13_Moving/BezierMover.cs b/Other/AstarPathfindingDemo/Packages/com.arongranberg.astar/ExampleScenes/Scenes/OldExamples/Example13_Moving/BezierMover.cs
new file mode 100644
index 0000000..05b33d7
--- /dev/null
+++ b/Other/AstarPathfindingDemo/Packages/com.arongranberg.astar/ExampleScenes/Scenes/OldExamples/Example13_Moving/BezierMover.cs
@@ -0,0 +1,96 @@
+using UnityEngine;
+
+namespace Pathfinding.Examples {
+	using Pathfinding.Drawing;
+
+	/// <summary>
+	/// Moves an object along a spline.
+	/// Helper script in the example scene called 'Moving'.
+	/// </summary>
+	[HelpURL("https://arongranberg.com/astar/documentation/stable/beziermover.html")]
+	public class BezierMover : VersionedMonoBehaviour {
+		public Transform[] points;
+
+		public float speed = 1;
+		public float tiltAmount = 1f;
+		public float tiltSmoothing = 1.0f;
+
+		float time = 0;
+		Vector3 averageCurvature;
+
+		Vector3 Evaluate (float t, out Vector3 derivative, out Vector3 secondDerivative, out Vector3 curvature) {
+			int c = points.Length;
+			int pt = (Mathf.FloorToInt(t) + c) % c;
+			var p0 = points[(pt-1+c)%c].position;
+			var p1 = points[pt].position;
+			var p2 = points[(pt+1)%c].position;
+			var p3 = points[(pt+2)%c].position;
+			var tprime = t - Mathf.FloorToInt(t);
+
+			CatmullRomToBezier(p0, p1, p2, p3, out var c0, out var c1, out var c2, out var c3);
+			derivative = AstarSplines.CubicBezierDerivative(c0, c1, c2, c3, tprime);
+			secondDerivative = AstarSplines.CubicBezierSecondDerivative(c0, c1, c2, c3, tprime);
+			curvature = Curvature(derivative, secondDerivative);
+			return AstarSplines.CubicBezier(c0, c1, c2, c3, tprime);
+		}
+
+		/// <summary>Converts a catmull-rom spline to bezier control points</summary>
+		static void CatmullRomToBezier (Vector3 p0, Vector3 p1, Vector3 p2, Vector3 p3, out Vector3 c0, out Vector3 c1, out Vector3 c2, out Vector3 c3) {
+			c0 = p1;
+			c1 = (-p0 + 6*p1 + 1*p2)*(1/6.0f);
+			c2 = (p1 + 6*p2 - p3)*(1/6.0f);
+			c3 = p2;
+		}
+
+		static Vector3 Curvature (Vector3 derivate, Vector3 secondDerivative) {
+			var dx = derivate.magnitude;
+
+			if (dx < 0.000001f) return Vector3.zero;
+			return Vector3.Cross(derivate, secondDerivative) / (dx*dx*dx);
+		}
+
+		/// <summary>Update is called once per frame</summary>
+		void Update () {
+			// Move the agent a small distance along the path, according to its speed
+			float mn = time;
+			float mx = time+1;
+
+			while (mx - mn > 0.0001f) {
+				float mid = (mn+mx)/2;
+
+				Vector3 p = Evaluate(mid, out var dummy1, out var dummy2, out var dummy3);
+				if ((p-transform.position).sqrMagnitude > (speed*Time.deltaTime)*(speed*Time.deltaTime)) {
+					mx = mid;
+				} else {
+					mn = mid;
+				}
+			}
+
+			time = (mn+mx)/2;
+
+			transform.position = Evaluate(time, out var derivative, out var dummy, out var curvature);
+
+			averageCurvature = Vector3.Lerp(averageCurvature, curvature, Time.deltaTime);
+
+			// Estimate the acceleration at the current point and use it to tilt the object inwards on the curve
+			var centripetalAcceleration = -Vector3.Cross(derivative.normalized, averageCurvature);
+			var up = new Vector3(0, 1/(tiltAmount + 0.00001f), 0) + centripetalAcceleration;
+			transform.rotation = Quaternion.LookRotation(derivative, up);
+		}
+
+		public override void DrawGizmos () {
+			if (points != null && points.Length >= 3) {
+				for (int i = 0; i < points.Length; i++) if (points[i] == null) return;
+
+				Vector3 pp = Evaluate(0, out var derivative, out var secondDerivative, out var curvature);
+				for (int pt = 0; pt < points.Length; pt++) {
+					for (int i = 1; i <= 100; i++) {
+						var p = Evaluate(pt + (i / 100f), out derivative, out secondDerivative, out curvature);
+						Draw.Line(pp, p, Color.white);
+						pp = p;
+					}
+				}
+			}
+		}
+	}
+}
-- 
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