Godot TouchScreen swipe detector

Question

I'm making a simple android mobile game in Godot3.1. I would need to make a swipe detector that would determine if the player swiped and in which direction (left or right).

I tried this:

var swipe_start = null
var minimum_drag = 100

func _unhandled_input(event):
if event.is_action_pressed("click"):
    swipe_start = event.get_position()
if event.is_action_released("click"):
    _calculate_swipe(event.get_position())

func _calculate_swipe(swipe_end):
  if swipe_start == null: 
    return
  var swipe = swipe_end - swipe_start
  if abs(swipe.x) > minimum_drag:
    if swipe.x > 0:
        _right()
    else:
        _left()

This works when you click with your mouse and swipe but it doesn't work when you play it on your android phone.

Any ideas?

Federico Ciuffardi Federico Ciuffardi · Accepted Answer · 2020-01-11T19:14:13

That code only considers clicks and not screen touches, to correct that you have two options:

Go to Project > Project Settings > Input Devices > Pointing and turn on the Emulate Mouse From Touch option.
Or use the following code:

func _unhandled_input(event):
  if event is InputEventScreenTouch:
    if event.pressed:
      swipe_start = event.get_position()
    else:
      _calculate_swipe(event.get_position())

instead of:

func _unhandled_input(event):
  if event.is_action_pressed("click"):
    swipe_start = event.get_position()
  if event.is_action_released("click"):
    _calculate_swipe(event.get_position())

With the last solution the code only accounts for screen touches so you wont be able to test it on PC unless you go to Project > Project Settings > Input Devices > Pointing and turn on the Emulate Touch From Mouse

Godot TouchScreen swipe detector

1 Answers