Swipe Detection in Unity

SwipeControls.cs

using UnityEngine;
using System.Collections;

public enum SwipeDirection 
{
	Null = 0,//no swipe detected
	Duck = 1,//swipe down detected
	Jump = 2,//swipe up detected
	Right = 3,//swipe right detected
	Left = 4//swipe left detected
}

public class SwipeControls : MonoBehaviour {
	
	//Constants
	private const float fSensitivity = 15;
	
	//VARIABLES
	//distance calculation
	private SwipeDirection sSwipeDirection;			//string to receive swipe output (Debug Only)
	private float fInitialX;
	private float fInitialY;
	private float fFinalX;
	private float fFinalY;
	private int iTouchStateFlag;	//flag to check
	private int ButtonStateFlag;
	
	private float inputX;				//x-coordinate
	private float inputY;				//y-coordinate
	private float slope;				//slope (m) of the the 
	private float fDistance;			//magnitude of distance between two positions

	void Start ()
	{
		fInitialX = 0.0f;
		fInitialY = 0.0f;
		fFinalX = 0.0f;
		fFinalY = 0.0f;
		
		inputX = 0.0f;
		inputY = 0.0f;
		
		iTouchStateFlag = 0;
		ButtonStateFlag = 0;
		sSwipeDirection = SwipeDirection.Null;
	}

	private KeyCode keyCode;
	void Update()
	{
		if (iTouchStateFlag == 0 && Input.GetMouseButtonDown(0))	//state 1 of swipe control
		{		
			fInitialX = Input.mousePosition.x;	//get the initial x mouse/ finger value
			fInitialY = Input.mousePosition.y;	//get the initial y mouse/ finger value
			
			sSwipeDirection = SwipeDirection.Null;
			iTouchStateFlag = 1;
		}		
		if (iTouchStateFlag == 1)	//state 2 of swipe control
		{
			fFinalX = Input.mousePosition.x;
			fFinalY = Input.mousePosition.y;
			
			sSwipeDirection = swipeDirection();	//get the swipe direction
			if (sSwipeDirection != SwipeDirection.Null)
				iTouchStateFlag = 2;
		}//end of state 1		
		if (iTouchStateFlag == 2 || Input.GetMouseButtonUp(0))	//state 3 of swipe control
		{
			//sSwipeDirection = SwipeDirection.Null;
			iTouchStateFlag = 0;
		}//end of M.R. swipe control

		if (Application.isEditor)
		{
			if (ButtonStateFlag == 0)//get key down
			{
				if (Input.GetKeyDown(KeyCode.W))
				{
					keyCode = KeyCode.W;
					ButtonStateFlag = 1;
				}
				else if (Input.GetKeyDown(KeyCode.UpArrow))
				{
					keyCode = KeyCode.UpArrow;
					ButtonStateFlag = 1;
				}
				else if (Input.GetKeyDown(KeyCode.A))
				{
					keyCode = KeyCode.A;
					ButtonStateFlag = 1;
				}
				else if (Input.GetKeyDown(KeyCode.LeftArrow))
				{
					keyCode = KeyCode.LeftArrow;
					ButtonStateFlag = 1;
				}
				else if (Input.GetKeyDown(KeyCode.D))
				{
					keyCode = KeyCode.D;
					ButtonStateFlag = 1;
				}
				else if (Input.GetKeyDown(KeyCode.RightArrow))
				{
					keyCode = KeyCode.RightArrow;
					ButtonStateFlag = 1;
				}
				else if (Input.GetKeyDown(KeyCode.S))
				{
					keyCode = KeyCode.S;
					ButtonStateFlag = 1;
				}
				else if (Input.GetKeyDown(KeyCode.DownArrow))
				{
					keyCode = KeyCode.DownArrow;
					ButtonStateFlag = 1;
				}
			}
			else if (ButtonStateFlag == 1)//wait for user to release key
			{
				if (keyCode == KeyCode.W || keyCode == KeyCode.UpArrow)
					sSwipeDirection = SwipeDirection.Jump;
				else if (keyCode == KeyCode.S || keyCode == KeyCode.DownArrow)
					sSwipeDirection = SwipeDirection.Duck;
				else if (keyCode == KeyCode.A || keyCode == KeyCode.LeftArrow)
					sSwipeDirection = SwipeDirection.Left;
				else if (keyCode == KeyCode.D || keyCode == KeyCode.RightArrow)
					sSwipeDirection = SwipeDirection.Right;

				ButtonStateFlag = 2;
			}
			else if (ButtonStateFlag == 2)//register the key press as an event
			{	
				if (Input.GetKeyUp(keyCode))
					ButtonStateFlag = 0;
			}
		}//end of if application is editor
	}//end of Update function
	
	/*
	*	FUNCTION: Calculate the swipe direction
	*/
	private SwipeDirection swipeDirection()
	{
		//calculate the slope of the swipe
		inputX = fFinalX - fInitialX;
		inputY = fFinalY - fInitialY;
		slope = inputY / inputX;
		
		//calculate the distance of tap start and end
		fDistance = Mathf.Sqrt( Mathf.Pow((fFinalY-fInitialY), 2) + Mathf.Pow((fFinalX-fInitialX), 2) );
		
		if (fDistance <= (Screen.width/fSensitivity))//higher the dividing factor higher the sensitivity
			return SwipeDirection.Null;
		
		if (inputX >= 0 && inputY > 0 && slope > 1)//first octant JUMP
		{		
			return SwipeDirection.Jump;
		}
		else if (inputX <= 0 && inputY > 0 && slope < -1)//eighth octant  JUMP
		{
			return SwipeDirection.Jump;
		}
		else if (inputX > 0 && inputY >= 0 && slope < 1 && slope >= 0)//second octant  RIGHT
		{
			return SwipeDirection.Right;
		}
		else if (inputX > 0 && inputY <= 0 && slope > -1 && slope <= 0)//third octant  RIGHT
		{
			return SwipeDirection.Right;
		}
		else if (inputX < 0 && inputY >= 0 && slope > -1 && slope <= 0)//seventh octant  LEFT
		{
			return SwipeDirection.Left;
		}
		else if (inputX < 0 && inputY <= 0 && slope >= 0 && slope < 1)//sixth octant  LEFT
		{
			return SwipeDirection.Left;
		}
		else if (inputX >= 0 && inputY < 0 && slope < -1)//fourth octant  DUCK
		{
			return SwipeDirection.Duck;
		}
		else if (inputX <= 0 && inputY < 0 && slope > 1)//fifth octant  DUCK
		{
			return SwipeDirection.Duck;
		}//end of else if
		
		return SwipeDirection.Null;	
	}//end of SwipeDirection function
	
	/*
	*	FUNCTION: Return swipe direction.
	*	RETURNS: Returns NULL if no swipes are detected.
	*			  Returns SwipeDirection if a swipe is detected
	*/
	public SwipeDirection getSwipeDirection()
	{
		if (sSwipeDirection != SwipeDirection.Null)
		{
			SwipeDirection etempSwipeDirection = sSwipeDirection;
			sSwipeDirection = SwipeDirection.Null;
			
			return etempSwipeDirection;
		}
		else
			return SwipeDirection.Null;
	}
}