Swipe Gesture iOS

Here's some code I threw together the other day to answer a similar question.

I'm sure it will need to be altered, but it's a good start.

It works surprisingly well (but not great) when I do an iPad build.

Note:

This is just an example script intended to demonstrate the basic concept.

Here's the idea:

• define a speed threshold: the minimum speed that determines a swipe

• each frame that has touchCount == 1, check if the speed is greater than the threshold

• if it is (and it wasn't the last frame) store the start position

• if it is not (and it was the last frame) store end position and/or do stuff (swipe is complete)

Here's some tested exactly twice code:

 var  swipeThresh      :    float  =   1.2;
 var  swipeStart       :  Vector2  =   Vector2.zero;
 var  swipeEnd         :  Vector2  =   Vector2.zero;
 var  swipeWasActive   :  boolean  =   false;
 
 function Update ()
 {
     if ( Input.touchCount == 1 ) {
         processSwipe();
     }
 }
 
 function OnGUI ()
 {
     processSwipe();
     drawStartBox();
     drawEndBox();
 }
 
 function processSwipe ()
 {
     if ( Input.touchCount != 1 ) {
         return;
     }
 
     var theTouch : Touch = Input.touches[0];
 
     /* skip the frame if deltaPosition is zero */
 
     if ( theTouch.deltaPosition == Vector2.zero ) {
         return;
     }
 
     var speedVec : Vector2 = theTouch.deltaPosition * theTouch.deltaTime;
     var theSpeed :   float = speedVec.magnitude;
 
     var swipeIsActive : boolean = ( theSpeed > swipeThresh );
 
     if ( swipeIsActive ) {
 
         if ( ! swipeWasActive ) {
             swipeStart = theTouch.position;
         }
     }
 
     else {
 
         if ( swipeWasActive ) {
             swipeEnd = theTouch.position;
             Debug.Log("Swipe Complete");
         }
     }
 
     swipeWasActive = swipeIsActive;
 }
 
 function drawStartBox ()
 {
     if ( swipeStart == Vector2.zero ) {
         return;
     }
 
     /* don't forget to invert the y-coordinate */
 
     var theY = Screen.height - swipeStart.y;
     var theX = swipeStart.x;
 
     var theRect : Rect = Rect(theX, theY, 140, 40);
 
     GUI.Label(theRect, "Start");
 }
 
 function drawEndBox ()
 {
     if ( swipeEnd == Vector2.zero ) {
         return;
     }
 
     /* don't forget to invert the y-coordinate */
 
     var theY = Screen.height - swipeEnd.y;
     var theX = swipeEnd.x;
 
     var theRect : Rect = Rect(theX, theY, 140, 40);
 
     GUI.Label(theRect, "End");
 }

I just gave this a try and it works surprisingly well...

I used a speed threshhold of 1.2, which can be adjusted in the Inspector.

Hope this helps!