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

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

namespace SicknessReduction.Visual.Vignetting
{

    public class DynamicVignetting : DynamicReductionSource
    {
        //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 https://patents.google.com/patent/US9645395B2/en
        //TODO: check Fernandes & Feiner


        [Header("Unity Objects")] public ForwardRendererData forwardRenderer;
        public Transform hmd;
        
        [Range(0, 1)] public float distInnerOuterRadius = .05f;

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

        protected override void Start()
        {
            blitFeature = (MaterialBlitFeature) forwardRenderer.rendererFeatures.FirstOrDefault(f =>
                f is MaterialBlitFeature && f.name.Equals("VignetteBlitFilter"));
            blitFeatureAvailable = blitFeature != null;

            if (!blitFeatureAvailable) return;
            // ReSharper disable once PossibleNullReferenceException
            blitFeatureMaterial = blitFeature.settings.MaterialToBlit;

            base.Start();
        }

        protected override void Update()
        {
            if (!blitFeatureAvailable) return;
            base.Update();

            var correctedRestriction = Mathf.Clamp(currentValue + change, 0, 1);

            if (correctedRestriction > 0f)
            {
                blitFeature.SetActive(true);
                UpdateMaterial(correctedRestriction);
                return;
            }

            blitFeature.SetActive(false);
        }

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

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