Initial Commit

Assets/Plugins/PropulsionPhysics/Scripts/TrajectoryMath.cs

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+using UnityEngine;
+using System.Collections;
+
+namespace Polycrime
+{
+	public static class TrajectoryMath
+	{
+		private static float verticalOnlyMin = 0.1f;
+
+		public static Vector2 CalculateVelocity(Vector2 startPoint, Vector2 endPoint, float time)
+		{
+			return CalculateVelocity(startPoint, endPoint, time, 1);
+		}
+
+		////////////////////////////////////////////////////////////////////////////////////
+			// If the target is far enough away, the normal trajectory is calculated based on 
+			// the editor's set gravity. A non-parabolic trajectory is calculated if the target
+			// is almost straight overhead. The verticalOnlyMin can be adjusted to when the
+			// velocity calculation should switch to vertical populsion only.
+		public static Vector2 CalculateVelocity(Vector2 startPoint, Vector2 endPoint, float time,float gravityMultiply)
+		{
+			Vector3 direction = (endPoint - startPoint);
+			float gravity = Physics.gravity.magnitude * gravityMultiply;
+			float yVelocity = (direction.y / time) + (0.5f * gravity * time);
+
+			if (TargetTooClose(startPoint, endPoint))
+			{
+				return new Vector3(0, yVelocity, 0);
+			}
+			else
+			{
+				return new Vector3(direction.x / time, yVelocity, direction.z / time);
+			}
+		}
+
+		public static Vector2 CalculateVelocityWithHeight(Vector2 startPoint, Vector2 endPoint, float maxHeight, float gravityMultiply)
+		{
+			float gravity = Physics2D.gravity.y * gravityMultiply;
+			Vector2 direction = (endPoint - startPoint);
+			var time = Mathf.Sqrt(-2 * maxHeight / gravity) + Mathf.Sqrt(2 * (direction.y - maxHeight) / gravity);
+			return new Vector2(direction.x / time,Mathf.Sqrt(-2 * gravity * maxHeight));
+		}
+
+		private static bool TargetTooClose(Vector3 startPoint, Vector3 endPoint)
+		{
+			Vector3 targetPosition = endPoint;
+			Vector3 leveledTarget = new Vector3(targetPosition.x, startPoint.y, targetPosition.z);
+
+			return Vector3.Distance(leveledTarget, startPoint) <= verticalOnlyMin;
+		}
+	}
+}