AirCurrent.cs (Check Current Segment)

public void CheckCurrentSegment(ParticleSystem startZone, ParticleSystem endZone)
{
	//We have a start and end position - A and B.
	A = startZone.transform.position;
	B = endZone.transform.position;

	//We have a Vector3 named AB which represents the line from A to B.

	//D will represent the closest point to the player that lies along the line AB.
	D = Vector3.zero;
	foreach (Player player in GameManager.Instance.players)
	{
		//C represents the player's position
		C = player.transform.position;

		//Define A to B by subtracting A's worldspace coord from B.
		AB = B - A;

		//Here is where we find the progressive travel down the line AB where D will fall.
		float t = Vector3.Dot(C - A, AB) / Vector3.Dot(AB, AB);

		//Create D by taking the percentage travel multiplied by the line (so 50% travel on a 8 unit vector is a 4 unit vector)
		//Add that vector to A and we have the location of D in worldspace.
		D = A + t * AB;

		//We don't need to create these vectors but I've done so for readability.
		//Find the distance from the player to the various points.
		Vector3 playerToD = player.transform.position - D;
		Vector3 playerToA = player.transform.position - A;
		Vector3 playerToB = player.transform.position - B;
		
		//If the distance from the player to D is less than the radius of the current, we assume the player is within the current
		if (playerToD.sqrMagnitude < currentRadius * currentRadius)
		{
			//The point D could potentially be outside of the two points
			//The point D can be outside of the line if this situation occurs:
			//
			//		  C
			//		  |
			//                |
			//		  D		A--------B

			bool betweenPoints = false;
			bool nearANode = false;
			bool nearBNode = false;
			bool overInputThreshhold = false;

			//T can potentially be negative or greater than one
			if (t > 0 && t < 1f)
			{
				//So we evaluate being between the points to handle the different cases accordingly.
				betweenPoints = true;
			}

			//If we're close to either end point, we want to know this.
			if (playerToA.sqrMagnitude < currentRadius * currentRadius)
			{
				nearANode = true;
			}
			if (playerToA.sqrMagnitude < currentRadius * currentRadius)
			{
				nearBNode = true;
			}

			//This is how the player escapes the air current.
			//One part listening to the player input
			float reverseInputAmt = 1 - Mathf.Clamp(player.controller.inputAmt, 0, 1);

			//Another part recognizing if the player has been recently affected by a
			//					strong force that should knock them from the current
			if (reverseInputAmt < .5f || player.controller.forceAmt > 2)
			{
				overInputThreshhold = true;
			}

			if (!overInputThreshhold)
			{
				//This makes the outer edges of the current not as potent.
				float distanceFallOffMultiplier = Mathf.Clamp(1 - (playerToD.magnitude / currentRadius), 0.5f, 1.0f);

				//Debug.Log("D Falloff: " + distanceFallOffMultiplier + "\n");

				//If the player is between the nodes or near a node
				//Set their velocity equal to zero
				//Disregard gravity
				//Apply a force that pushes them towards the next node & to the center.
				//The force applied is semi-negated if they are being affected by other sources.

				//This isn't the greatest if check but it gets the job done.
				//Other components going on: The near node cases of A and B, B
				//		The near node cases of A and B are different from between. B doesn't push player to the center, so if they walk near the exit, force is in the direction of the current and doesn't push the player to the middle.
				//		The distance fall off multiplier is clamped to half as powerful, so the current applies effect 
				if (betweenPoints)
				{
					player.controller.mRigidBody.velocity = Vector3.zero;
					player.controller.mRigidBody.useGravity = false;
					player.controller.ApplyConstantForce(distanceFallOffMultiplier * reverseInputAmt * AB.normalized * pushSpeed + -playerToD * pushSpeed / 5, true, true);

					//Tracking if the player is in a current is gameplay relevant - say a player did bonus damage in a current, etc.
					player.controller.InCurrent = true;
				}
				else if (nearANode)
				{
					player.controller.mRigidBody.velocity = Vector3.zero;
					player.controller.mRigidBody.useGravity = false;
					player.controller.ApplyConstantForce(distanceFallOffMultiplier * reverseInputAmt * AB.normalized * pushSpeed + -playerToD * pushSpeed / 5, true, true);

					//Tracking if the player is in a current is gameplay relevant - say a player did bonus damage in a current, etc.
					player.controller.InCurrent = true;
				}
				else if (nearBNode)
				{
					player.controller.mRigidBody.velocity = Vector3.zero;
					player.controller.mRigidBody.useGravity = false;
					player.controller.ApplyConstantForce(distanceFallOffMultiplier * reverseInputAmt * AB.normalized * pushSpeed, true, true);

					//Tracking if the player is in a current is gameplay relevant - say a player did bonus damage in a current, etc.
					player.controller.InCurrent = true;
				}
			}
		}
		else
		{
			player.controller.mRigidBody.useGravity = true;
		}
	}
}