HapticRack.cs

//======= Copyright (c) Valve Corporation, All rights reserved. ===============
//
// Purpose: Triggers haptic pulses based on a linear mapping
//
//=============================================================================

using UnityEngine;
using UnityEngine.Events;
using System.Collections;

namespace Valve.VR.InteractionSystem
{
    //-------------------------------------------------------------------------
    [RequireComponent( typeof( Interactable ) )]
    public class HapticRack : MonoBehaviour
    {
        [Tooltip( "The linear mapping driving the haptic rack" )]
        public LinearMapping linearMapping;

        [Tooltip( "The number of haptic pulses evenly distributed along the mapping" )]
        public int teethCount = 128;

        [Tooltip( "Minimum duration of the haptic pulse" )]
        public int minimumPulseDuration = 500;

        [Tooltip( "Maximum duration of the haptic pulse" )]
        public int maximumPulseDuration = 900;

        [Tooltip( "This event is triggered every time a haptic pulse is made" )]
        public UnityEvent onPulse;

        private Hand hand;
        private int previousToothIndex = -1;

        //-------------------------------------------------
        void Awake()
        {
            if ( linearMapping == null )
            {
                linearMapping = GetComponent<LinearMapping>();
            }
        }


        //-------------------------------------------------
        private void OnHandHoverBegin( Hand hand )
        {
            this.hand = hand;
        }


        //-------------------------------------------------
        private void OnHandHoverEnd( Hand hand )
        {
            this.hand = null;
        }


        //-------------------------------------------------
        void Update()
        {
            int currentToothIndex = Mathf.RoundToInt( linearMapping.value * teethCount - 0.5f );
            if ( currentToothIndex != previousToothIndex )
            {
                Pulse();
                previousToothIndex = currentToothIndex;
            }
        }


        //-------------------------------------------------
        private void Pulse()
        {
            if ( hand && ( hand.controller != null ) && ( hand.GetStandardInteractionButton() ) )
            {
                ushort duration = (ushort)Random.Range( minimumPulseDuration, maximumPulseDuration + 1 );
                hand.controller.TriggerHapticPulse( duration );

                onPulse.Invoke();
            }
        }
    }
}