VRCycling/Assets/Scripts/SicknessReduction/Visual/Vignetting/DynamicVignetting.cs

using System.Linq;
using Controller.Bicycle;
using SicknessReduction.Visual.Rendering;
using UnityEngine;
using UnityEngine.Rendering.Universal;

namespace SicknessReduction.Visual.Vignetting
{
    public class DynamicVignetting : MonoBehaviour
    {
        //TODO: cite https://www.researchgate.net/publication/326760789_Assessing_vignetting_as_a_means_to_reduce_VR_sickness_during_amplified_head_rotations
        //TODO: there is a patent for this (WTF) https://patents.google.com/patent/US9645395B2/en
        //TODO: check Fernandes & Feiner

        private const float DIST_IFOV_OVOF = .2f;

        [Header("Unity Objects")] public ForwardRendererData forwardRenderer;
        public RbBicycleController bikeController;
        public Transform hmd;

        [Header("Restriction Data")] public float minRestriction = 0f; //from Fernandes & Feiner
        public float maxRestriction = 80f; //from Fernandes & Feiner
        public float angularVelocityThreshold = 20f; //deg/sec check in Fernandes & Feiner
        public float steerAngleThreshold = 15f; //deg/sec check in Fernandes & Feiner
        public float leanAngleThreshold = 20f; //deg/sec check in Fernandes & Feiner

        //TODO: figure out what angular velocity means in my context
        private MaterialBlitFeature blitFeature;
        private Material blitFeatureMaterial;
        private bool blitFeatureAvailable;

        private QueueBasedRestrictionSuggestor leaningAngleSuggestor;
        private QueueBasedRestrictionSuggestor hmdAngleSuggestor;

        private void Start()
        {
            blitFeature = (MaterialBlitFeature) forwardRenderer.rendererFeatures.FirstOrDefault(f =>
                f is MaterialBlitFeature && f.name.Equals("VignetteBlitFilter"));
            blitFeatureAvailable = blitFeature != null;
            if (!blitFeatureAvailable) return;
            blitFeatureMaterial = blitFeature.settings.MaterialToBlit;
        }

        private void Update()
        {
            if (!blitFeatureAvailable) return;
            if (Mathf.Abs(bikeController.CurrentSteerAngle) >= steerAngleThreshold)
            {
                blitFeature.SetActive(true);
                UpdateMaterial(.6f); //TODO: no magic number
                return;
            }

            //TODO: figure out how to combine everything
            blitFeature.SetActive(false);
        }

        private void UpdateMaterial(float restriction)
        {
            var r = Mathf.Clamp(1 - restriction, 0, 1);
            blitFeatureMaterial.SetFloat("_OFOV", r);
            blitFeatureMaterial.SetFloat("_IFOV", Mathf.Clamp(r - DIST_IFOV_OVOF, 0, 1));
        }

        private void OnDestroy()
        {
            if (!blitFeatureAvailable) return;
            blitFeature.SetActive(false);
        }
    }
}