//using UnityEngine.Rendering;

//namespace UnityEngine.PostProcessing
//{
//    using DebugMode = BuiltinDebugViewsModel.Mode;

//    public sealed class DepthOfFieldComponent : PostProcessingComponentRenderTexture<DepthOfFieldModel>
//    {
//        static class Uniforms
//        {
//            internal static readonly int _DepthOfFieldTex = Shader.PropertyToID("_DepthOfFieldTex");
//            internal static readonly int _Distance = Shader.PropertyToID("_Distance");
//            internal static readonly int _LensCoeff = Shader.PropertyToID("_LensCoeff");
//            internal static readonly int _MaxCoC = Shader.PropertyToID("_MaxCoC");
//            internal static readonly int _RcpMaxCoC = Shader.PropertyToID("_RcpMaxCoC");
//            internal static readonly int _RcpAspect = Shader.PropertyToID("_RcpAspect");
//            internal static readonly int _MainTex = Shader.PropertyToID("_MainTex");
//            internal static readonly int _HistoryCoC = Shader.PropertyToID("_HistoryCoC");
//        }

//        const string k_ShaderString = "Hidden/Post FX/Depth Of Field";

//        public override bool active
//        {
//            get
//            {
//                return model.enabled
//                       && SystemInfo.SupportsRenderTextureFormat(RenderTextureFormat.ARGBHalf)
//                       && SystemInfo.SupportsRenderTextureFormat(RenderTextureFormat.RHalf)
//                       && !context.interrupted;
//            }
//        }

//        public override DepthTextureMode GetCameraFlags()
//        {
//            return DepthTextureMode.Depth;
//        }

//        RenderTexture m_CoCHistory;
//        RenderBuffer[] m_MRT = new RenderBuffer[2];

//        // Height of the 35mm full-frame format (36mm x 24mm)
//        const float k_FilmHeight = 0.024f;

//        float CalculateFocalLength()
//        {
//            var settings = model.settings;

//            if (!settings.useCameraFov)
//                return settings.focalLength / 1000f;

//            float fov = context.camera.fieldOfView * Mathf.Deg2Rad;
//            return 0.5f * k_FilmHeight / Mathf.Tan(0.5f * fov);
//        }

//        float CalculateMaxCoCRadius(int screenHeight)
//        {
//            // Estimate the allowable maximum radius of CoC from the kernel
//            // size (the equation below was empirically derived).
//            float radiusInPixels = (float)model.settings.kernelSize * 4f + 10f;

//            // Applying a 5% limit to the CoC radius to keep the size of
//            // TileMax/NeighborMax small enough.
//            return Mathf.Min(0.05f, radiusInPixels / screenHeight);
//        }

//        public void Prepare(RenderTexture source, Material uberMaterial, bool antialiasCoC)
//        {
//            var settings = model.settings;

//            // Material setup
//            var material = context.materialFactory.Get(k_ShaderString);
//            material.shaderKeywords = null;

//            var s1 = settings.focusDistance;
//            var f = CalculateFocalLength();
//            s1 = Mathf.Max(s1, f);
//            material.SetFloat(Uniforms._Distance, s1);

//            var coeff = f * f / (settings.aperture * (s1 - f) * k_FilmHeight * 2);
//            material.SetFloat(Uniforms._LensCoeff, coeff);

//            var maxCoC = CalculateMaxCoCRadius(source.height);
//            material.SetFloat(Uniforms._MaxCoC, maxCoC);
//            material.SetFloat(Uniforms._RcpMaxCoC, 1f / maxCoC);

//            var rcpAspect = (float)source.height / source.width;
//            material.SetFloat(Uniforms._RcpAspect, rcpAspect);

//            var rt1 = context.renderTextureFactory.Get(context.width / 2, context.height / 2, 0, RenderTextureFormat.ARGBHalf);
//            source.filterMode = FilterMode.Point;

//            // Pass #1 - Downsampling, prefiltering and CoC calculation
//            Graphics.Blit(source, rt1, material, 0);

//            // Pass #2 - CoC Antialiasing
//            var pass = rt1;
//            if (antialiasCoC)
//            {
//                pass = context.renderTextureFactory.Get(context.width / 2, context.height / 2, 0, RenderTextureFormat.ARGBHalf);

//                if (m_CoCHistory == null || !m_CoCHistory.IsCreated() || m_CoCHistory.width != context.width / 2 || m_CoCHistory.height != context.height / 2)
//                {
//                    m_CoCHistory = RenderTexture.GetTemporary(context.width / 2, context.height / 2, 0, RenderTextureFormat.RHalf);
//                    m_CoCHistory.filterMode = FilterMode.Point;
//                    m_CoCHistory.name = "CoC History";
//                    Graphics.Blit(rt1, m_CoCHistory, material, 6);
//                }

//                var tempCoCHistory = RenderTexture.GetTemporary(context.width / 2, context.height / 2, 0, RenderTextureFormat.RHalf);
//                tempCoCHistory.filterMode = FilterMode.Point;
//                tempCoCHistory.name = "CoC History";

//                m_MRT[0] = pass.colorBuffer;
//                m_MRT[1] = tempCoCHistory.colorBuffer;
//                material.SetTexture(Uniforms._MainTex, rt1);
//                material.SetTexture(Uniforms._HistoryCoC, m_CoCHistory);
//                Graphics.SetRenderTarget(m_MRT, rt1.depthBuffer);
//                GraphicsUtils.Blit(material, 5);

//                RenderTexture.ReleaseTemporary(m_CoCHistory);
//                m_CoCHistory = tempCoCHistory;
//            }

//            // Pass #3 - Bokeh simulation
//            var rt2 = context.renderTextureFactory.Get(context.width / 2, context.height / 2, 0, RenderTextureFormat.ARGBHalf);
//            Graphics.Blit(pass, rt2, material, 1 + (int)settings.kernelSize);

//            if (context.profile.debugViews.IsModeActive(DebugMode.FocusPlane))
//            {
//                uberMaterial.SetTexture(Uniforms._DepthOfFieldTex, rt1);
//                uberMaterial.SetFloat(Uniforms._MaxCoC, maxCoC);
//                uberMaterial.EnableKeyword("DEPTH_OF_FIELD_COC_VIEW");
//                context.Interrupt();
//            }
//            else
//            {
//                uberMaterial.SetTexture(Uniforms._DepthOfFieldTex, rt2);
//                uberMaterial.EnableKeyword("DEPTH_OF_FIELD");
//            }

//            if (antialiasCoC)
//                context.renderTextureFactory.Release(pass);

//            context.renderTextureFactory.Release(rt1);
//            source.filterMode = FilterMode.Bilinear;
//        }

//        public override void OnDisable()
//        {
//            if (m_CoCHistory != null)
//                RenderTexture.ReleaseTemporary(m_CoCHistory);

//            m_CoCHistory = null;
//        }
//    }
//}