bubble_client/Assets/Plugins/SmartLevelsMap/Scripts/SplineCurve.cs

using UnityEngine;

namespace Assets.Plugins.SmartLevelsMap.Scripts
{
	public class SplineCurve
	{
		private readonly Vector2[] _points;

		public SplineCurve()
		{
			_points = new Vector2[4];
		}

		public void ApplyPoints(Vector2 p1, Vector2 p2, Vector2 p3, Vector2 p4)
		{
			_points[0] = p1;
			_points[1] = p2;
			_points[2] = p3;
			_points[3] = p4;
		}

		public Vector2 GetPoint(float t)
		{
			return GetPoint(_points[0], _points[1], _points[2], _points[3], t);
		}

		public static Vector2 GetPoint(Vector2 a, Vector2 b, Vector2 c, Vector2 d, float t)
		{
			//t==0, ret b
			//t==1, ret c
			return .5f*(
				(-a + 3f*b - 3f*c + d)*(t*t*t)
				+ (2f*a - 5f*b + 4f*c - d)*(t*t)
				+ (-a + c)*t
				+ 2f*b
				);	
		}
	}
}