Swipe Input Controller

Detects touch swipes in four directions with configurable thresholds and dead zones. Fires UnityEvents for each swipe direction with speed and distance tracking.

Unity 2022.3+ · 3.4 KB · SwipeInputController.cs

How to Use

Create an empty GameObject named SwipeManager

Attach the SwipeInputController script to it

Set the minimum swipe distance threshold in the inspector

Wire up the onSwipeUp/Down/Left/Right UnityEvents to your game logic

Test on a mobile device or use mouse input in the editor

Features

4-directional swipe detection
Configurable swipe threshold
Swipe speed and distance tracking
Events for swipe start/end/direction
Dead zone filtering

When to Use This

Built for mobile games that use swipe gestures — card games, puzzle games, endless runners with lane switching. Essential for any touch-based game that needs directional input beyond simple taps.

Common Mistakes

Test on actual devices, not just the Unity Remote — touch behavior differs significantly. The minSwipeDistance threshold needs tuning per device DPI; what feels natural on a phone may be too sensitive on a tablet. Don't forget to handle multi-touch if your game uses simultaneous gestures.

Source Code

  
 SwipeInputController.cs
C# 
using UnityEngine;
using UnityEngine.Events;

public class SwipeInputController : MonoBehaviour
{
    [Header("Swipe Settings")]
    [SerializeField] private float minSwipeDistance = 50f;
    [SerializeField] private float maxSwipeTime = 0.5f;
    [SerializeField] private float deadZone = 20f;

    [Header("Events")]
    public UnityEvent onSwipeUp;
    public UnityEvent onSwipeDown;
    public UnityEvent onSwipeLeft;
    public UnityEvent onSwipeRight;
    public UnityEvent<Vector2> onSwipeStart;
    public UnityEvent<Vector2, float, float> onSwipeEnd; // direction, speed, distance

    public enum SwipeDirection { None, Up, Down, Left, Right }

    public SwipeDirection LastSwipeDirection { get; private set; }
    public float LastSwipeSpeed { get; private set; }
    public float LastSwipeDistance { get; private set; }
    public bool IsSwiping { get; private set; }

    private Vector2 touchStartPos;
    private float touchStartTime;
    private bool tracking;

    private void Update()
    {
        if (Input.touchCount > 0)
        {
            Touch touch = Input.GetTouch(0);
            HandleTouch(touch.phase, touch.position);
        }
        else
        {
            // Mouse fallback for editor testing
            if (Input.GetMouseButtonDown(0))
                HandleTouch(TouchPhase.Began, Input.mousePosition);
            else if (Input.GetMouseButton(0))
                HandleTouch(TouchPhase.Moved, Input.mousePosition);
            else if (Input.GetMouseButtonUp(0))
                HandleTouch(TouchPhase.Ended, Input.mousePosition);
        }
    }

    private void HandleTouch(TouchPhase phase, Vector2 position)
    {
        switch (phase)
        {
            case TouchPhase.Began:
                touchStartPos = position;
                touchStartTime = Time.time;
                tracking = true;
                IsSwiping = true;
                onSwipeStart?.Invoke(position);
                break;

            case TouchPhase.Ended:
            case TouchPhase.Canceled:
                if (!tracking) return;
                tracking = false;
                IsSwiping = false;
                ProcessSwipe(position);
                break;
        }
    }

    private void ProcessSwipe(Vector2 endPos)
    {
        float elapsed = Time.time - touchStartTime;
        if (elapsed > maxSwipeTime) return;

        Vector2 delta = endPos - touchStartPos;
        float distance = delta.magnitude;

        if (distance < minSwipeDistance) return;

        float speed = distance / Mathf.Max(elapsed, 0.001f);
        LastSwipeDistance = distance;
        LastSwipeSpeed = speed;

        SwipeDirection direction = GetSwipeDirection(delta);
        LastSwipeDirection = direction;

        onSwipeEnd?.Invoke(delta.normalized, speed, distance);

        switch (direction)
        {
            case SwipeDirection.Up: onSwipeUp?.Invoke(); break;
            case SwipeDirection.Down: onSwipeDown?.Invoke(); break;
            case SwipeDirection.Left: onSwipeLeft?.Invoke(); break;
            case SwipeDirection.Right: onSwipeRight?.Invoke(); break;
        }
    }

    private SwipeDirection GetSwipeDirection(Vector2 delta)
    {
        if (Mathf.Abs(delta.x) < deadZone && Mathf.Abs(delta.y) < deadZone)
            return SwipeDirection.None;

        if (Mathf.Abs(delta.x) > Mathf.Abs(delta.y))
        {
            return delta.x > 0 ? SwipeDirection.Right : SwipeDirection.Left;
        }
        else
        {
            return delta.y > 0 ? SwipeDirection.Up : SwipeDirection.Down;
        }
    }

    public void ResetSwipe()
    {
        LastSwipeDirection = SwipeDirection.None;
        LastSwipeSpeed = 0f;
        LastSwipeDistance = 0f;
        tracking = false;
        IsSwiping = false;
    }
}
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