moloch/Assets/Scripts/Audio/Narrator/SubtitleManager.cs

using FMOD.Studio;
using FMODUnity;
using System.Collections;
using System.Collections.Generic;
using TMPro;
using Unity.VisualScripting;
using UnityEngine;

namespace Moloch
{
    public class SubtitleManager : MonoBehaviour
    {
        [Header("Text")]
        [SerializeField]
        private TMP_Text m_Text;

        [Header("Audio")]
        [SerializeField]
        private EventReference m_NarrationSFX;
        [SerializeField]
        private EventInstance m_NarrationSFXInst; 

        private float m_TimeElapsed;

        private bool m_FirstRun;

        private void OnEnable()
        {
            NarrationManager.m_UpdateSubtitile += UpdateText;
        }

        private void OnDisable()
        {
            NarrationManager.m_UpdateSubtitile -= UpdateText;
        }

        private void Start()
        {
            m_Text = GetComponent<TextMeshProUGUI>();
            m_TimeElapsed = 0;
            m_Text.text = "";
            m_FirstRun = true;
        }

        private void UpdateText(string sentence, float waitTime)
        {
            FMOD.Studio.PLAYBACK_STATE state;

            m_NarrationSFXInst =  AudioManager.instance.PlaySound(m_NarrationSFX);

            m_NarrationSFXInst.getPlaybackState(out state);

            if(m_FirstRun)
            {
                m_FirstRun = false;
                m_NarrationSFXInst.start();
            }
            else
            {
                m_NarrationSFXInst.getPlaybackState(out state);
                if(state == PLAYBACK_STATE.STOPPED)
                {
                    m_NarrationSFXInst.start();
                }
            }
            StartCoroutine(TextScroll(sentence, waitTime));
        }

        // Wait time, how long the text will stay on the screen for + if the audio stops late, apply an offset
        private IEnumerator ClearText(float waitTime, bool earlyStop) 
        {
            var offset = (waitTime - m_TimeElapsed)  * Random.Range(0.6f, 0.95f);
            float earlyOffset = 0;

            if (!earlyStop)
            {
                earlyOffset = offset / Random.Range(2, 4);
                offset -= earlyOffset;
                yield return new WaitForSecondsRealtime(earlyOffset);
                AudioManager.instance.StopSound(m_NarrationSFXInst);
            }
            yield return new WaitForSecondsRealtime(offset);
            m_Text.text = "";
            m_TimeElapsed = 0;
        }

        private IEnumerator TextScroll(string sentence, float waitTime)
        {
            var characterLength = sentence.ToCharArray().Length;
            int randomStoppingValue = (int) Random.Range(characterLength * 0.6f, characterLength); 
            var index = 0;
            bool earlyStop = false;

            if(Random.Range(0f, 10f) > 6) earlyStop = true;

            foreach (char c in sentence.ToCharArray())
            {
                index++;
                m_Text.text += c;
                float randomInterval = Random.Range(0.02f, 0.04f);
                yield return new WaitForSecondsRealtime(randomInterval);
                m_TimeElapsed += randomInterval;

                // Stop audio early based on probability
                if( randomStoppingValue == index && earlyStop)
                {
                    AudioManager.instance.StopSound(m_NarrationSFXInst);
                }
            }
            StartCoroutine(ClearText(waitTime, earlyStop));
        }
    }
}