using UnityEngine.Rendering;
using UnityEngine.Experimental.Rendering;
using System.Collections.Generic;
using System;

namespace UnityEngine.Experimental.ScriptableRenderLoop
{
    [ExecuteInEditMode]
    // This HDRenderLoop assume linear lighting. Don't work with gamma.
    public partial class HDRenderLoop : ScriptableRenderLoop
    {
        const string k_HDRenderLoopPath = "Assets/ScriptableRenderLoop/HDRenderLoop/HDRenderLoop.asset";

#if UNITY_EDITOR
        [UnityEditor.MenuItem("Renderloop/CreateHDRenderLoop")]
        static void CreateHDRenderLoop()
        {
            var instance = ScriptableObject.CreateInstance<HDRenderLoop>();
            UnityEditor.AssetDatabase.CreateAsset(instance, k_HDRenderLoopPath);
        }

        [UnityEditor.MenuItem("HDRenderLoop/Add \"Additional Light Data\" (if not present)")]
        static void AddAdditionalLightData()
        {
            Light[] lights = FindObjectsOfType(typeof(Light)) as Light[];

            foreach (Light light in lights)
            {
                // Do not add a component if there already is one.
                if (light.GetComponent<AdditionalLightData>() == null)
                {
                    light.gameObject.AddComponent<AdditionalLightData>();
                }
            }
        }
#endif

        SkyRenderer m_SkyRenderer = null;
        [SerializeField]
        SkyParameters m_SkyParameters = new SkyParameters();
 
        public SkyParameters skyParameters
        {
            get { return m_SkyParameters; }
        }

        public class DebugParameters
        {
            // Material Debugging
            public int debugViewMaterial = 0;

            // Rendering debugging
            public bool displayOpaqueObjects = true;
            public bool displayTransparentObjects = true;

            public bool useForwardRenderingOnly = false; // TODO: Currently there is no way to strip the extra forward shaders generated by the shaders compiler, so we can switch dynamically.
            public bool useDepthPrepass = false;

            public bool enableTonemap = true;
            public float exposure = 0;
        }

        DebugParameters m_DebugParameters = new DebugParameters();
        public DebugParameters debugParameters
        {
            get { return m_DebugParameters; }
        }

        public class GBufferManager
        {
            public const int MaxGbuffer = 8;

            public void SetBufferDescription(int index, string stringId, RenderTextureFormat inFormat, RenderTextureReadWrite inSRGBWrite)
            {
                IDs[index] = Shader.PropertyToID(stringId);
                RTIDs[index] = new RenderTargetIdentifier(IDs[index]);
                formats[index] = inFormat;
                sRGBWrites[index] = inSRGBWrite;
            }

            public void InitGBuffers(int width, int height, CommandBuffer cmd)
            {
                for (int index = 0; index < gbufferCount; index++)
                {
                    /* RTs[index] = */ cmd.GetTemporaryRT(IDs[index], width, height, 0, FilterMode.Point, formats[index], sRGBWrites[index]);
                }
            }

            public RenderTargetIdentifier[] GetGBuffers()
            {
                var colorMRTs = new RenderTargetIdentifier[gbufferCount];
                for (int index = 0; index < gbufferCount; index++)
                {
                    colorMRTs[index] = RTIDs[index];
                }


                return colorMRTs;
            }
        
            /*
            public void BindBuffers(Material mat)
            {
                for (int index = 0; index < gbufferCount; index++)
                {
                    mat.SetTexture(IDs[index], RTs[index]);
                }
            }
            */

            public int gbufferCount { get; set; }
            int[] IDs = new int[MaxGbuffer];
            RenderTargetIdentifier[] RTIDs = new RenderTargetIdentifier[MaxGbuffer];
            RenderTextureFormat[] formats = new RenderTextureFormat[MaxGbuffer];
            RenderTextureReadWrite[] sRGBWrites = new RenderTextureReadWrite[MaxGbuffer];
        }

        GBufferManager m_gbufferManager = new GBufferManager();

        [SerializeField]
        ShadowSettings m_ShadowSettings = ShadowSettings.Default;

        public ShadowSettings shadowSettings
        {
            get { return m_ShadowSettings; }
        }

        ShadowRenderPass m_ShadowPass;


        public const int k_MaxDirectionalLightsOnSCreen = 2;
        public const int k_MaxPunctualLightsOnSCreen = 512;
        public const int k_MaxAreaLightsOnSCreen = 128;
        public const int k_MaxEnvLightsOnSCreen = 64;
        public const int k_MaxShadowOnScreen = 16;
        public const int k_MaxCascadeCount = 4; //Should be not less than m_Settings.directionalLightCascadeCount;

        [SerializeField]
        TextureSettings m_TextureSettings = TextureSettings.Default;

        // Various set of material use in render loop
        Material m_FinalPassMaterial;
        Material m_DebugViewMaterialGBuffer;

        // Various buffer
        int m_CameraColorBuffer;
        int m_CameraDepthBuffer;
        int m_VelocityBuffer;
        int m_DistortionBuffer;

        RenderTargetIdentifier m_CameraColorBufferRT;
        RenderTargetIdentifier m_CameraDepthBufferRT;
        RenderTargetIdentifier m_VelocityBufferRT;
        RenderTargetIdentifier m_DistortionBufferRT;
		
        public class LightList
        {
            public List<DirectionalLightData> directionalLights;
            public List<DirectionalShadowData> directionalShadows;
            public List<LightData> punctualLights;
            public List<PunctualShadowData> punctualShadows;
            public List<LightData> areaLights;
            public List<EnvLightData> envLights;
            public Vector4[] directionalShadowSplitSphereSqr;

            // Index mapping list to go from GPU lights (above) to CPU light (in cullResult)
            public List<int> directionalCullIndices;
            public List<int> punctualCullIndices;
            public List<int> areaCullIndices;
            public List<int> envCullIndices;

            public void Clear()
            {
                directionalLights.Clear();
                directionalShadows.Clear();
                punctualLights.Clear();
                punctualShadows.Clear();
                areaLights.Clear();
                envLights.Clear();

                directionalCullIndices.Clear();
                punctualCullIndices.Clear();
                areaCullIndices.Clear();
                envCullIndices.Clear();
            }

            public void Allocate()
            {
                directionalLights = new List<DirectionalLightData>();
                punctualLights = new List<LightData>();
                areaLights = new List<LightData>();
                envLights = new List<EnvLightData>();
                punctualShadows = new List<PunctualShadowData>();
                directionalShadows = new List<DirectionalShadowData>();
                directionalShadowSplitSphereSqr = new Vector4[k_MaxCascadeCount];

                directionalCullIndices = new List<int>();
                punctualCullIndices = new List<int>();
                areaCullIndices = new List<int>();
                envCullIndices = new List<int>();
            }
        }

        LightList m_lightList;

        // Detect when windows size is changing
        int m_WidthOnRecord;
        int m_HeightOnRecord;

        // TODO: Find a way to automatically create/iterate through lightloop
        SinglePass.LightLoop m_SinglePassLightLoop;
        TilePass.LightLoop m_TilePassLightLoop;

        // TODO: Find a way to automatically create/iterate through deferred material
        Lit.RenderLoop m_LitRenderLoop;

        TextureCacheCubemap m_CubeReflTexArray;
        TextureCache2D m_CookieTexArray;
        TextureCacheCubemap m_CubeCookieTexArray;

        void OnEnable()
        {
            Rebuild();
        }

        void OnValidate()
        {
            Rebuild();
        }

        public override void Rebuild()
        {
            m_CameraColorBuffer  = Shader.PropertyToID("_CameraColorTexture");
            m_CameraDepthBuffer  = Shader.PropertyToID("_CameraDepthTexture");

            m_CameraColorBufferRT = new RenderTargetIdentifier(m_CameraColorBuffer);
            m_CameraDepthBufferRT = new RenderTargetIdentifier(m_CameraDepthBuffer);

            m_SkyRenderer = new SkyRenderer();
            m_SkyRenderer.Rebuild();

            m_FinalPassMaterial  = Utilities.CreateEngineMaterial("Hidden/HDRenderLoop/FinalPass");
            m_DebugViewMaterialGBuffer = Utilities.CreateEngineMaterial("Hidden/HDRenderLoop/DebugViewMaterialGBuffer");

            m_ShadowPass = new ShadowRenderPass(m_ShadowSettings);

            // Init Gbuffer description
            m_LitRenderLoop = new Lit.RenderLoop(); // Our object can be garbage collected, so need to be allocate here

            m_gbufferManager.gbufferCount = m_LitRenderLoop.GetMaterialGBufferCount();
            RenderTextureFormat[] RTFormat; RenderTextureReadWrite[] RTReadWrite;
            m_LitRenderLoop.GetMaterialGBufferDescription(out RTFormat, out RTReadWrite);

            for (int gbufferIndex = 0; gbufferIndex < m_gbufferManager.gbufferCount; ++gbufferIndex)
            {
                m_gbufferManager.SetBufferDescription(gbufferIndex, "_GBufferTexture" + gbufferIndex, RTFormat[gbufferIndex], RTReadWrite[gbufferIndex]);
            }

#pragma warning disable 162 // warning CS0162: Unreachable code detected
            m_VelocityBuffer = Shader.PropertyToID("_VelocityTexture");
            if (ShaderConfig.VelocityInGbuffer == 1)
            {
                // If velocity is in GBuffer then it is in the last RT. Assign a different name to it.
                m_gbufferManager.SetBufferDescription(m_gbufferManager.gbufferCount, "_VelocityTexture", Builtin.RenderLoop.GetVelocityBufferFormat(), Builtin.RenderLoop.GetVelocityBufferReadWrite());
                m_gbufferManager.gbufferCount++;
            }
            m_VelocityBufferRT = new RenderTargetIdentifier(m_VelocityBuffer);
#pragma warning restore 162

            m_DistortionBuffer = Shader.PropertyToID("_DistortionTexture");
            m_DistortionBufferRT = new RenderTargetIdentifier(m_DistortionBuffer);

            m_LitRenderLoop.Rebuild();

            m_CookieTexArray = new TextureCache2D();
            m_CookieTexArray.AllocTextureArray(8, (int)m_TextureSettings.spotCookieSize, (int)m_TextureSettings.spotCookieSize, TextureFormat.RGBA32, true);
            m_CubeCookieTexArray = new TextureCacheCubemap();
            m_CubeCookieTexArray.AllocTextureArray(4, (int)m_TextureSettings.pointCookieSize, TextureFormat.RGBA32, true);
            m_CubeReflTexArray = new TextureCacheCubemap();
            m_CubeReflTexArray.AllocTextureArray(32, (int)m_TextureSettings.reflectionCubemapSize, TextureFormat.BC6H, true);

            // Init various light loop
            m_SinglePassLightLoop = new SinglePass.LightLoop();
            m_SinglePassLightLoop.Rebuild();
            m_TilePassLightLoop = new TilePass.LightLoop();
            m_TilePassLightLoop.Rebuild();

            m_lightList = new LightList();
            m_lightList.Allocate();
        }

        void OnDisable()
        {
            m_LitRenderLoop.OnDisable();
            m_SinglePassLightLoop.OnDisable();
            m_TilePassLightLoop.OnDisable();

            Utilities.Destroy(m_FinalPassMaterial);
            Utilities.Destroy(m_DebugViewMaterialGBuffer);

            m_CubeReflTexArray.Release();
            m_CookieTexArray.Release();
            m_CubeCookieTexArray.Release();

            m_SkyRenderer.OnDisable();
        }

        void NewFrame()
        {
            m_CookieTexArray.NewFrame();
            m_CubeCookieTexArray.NewFrame();
            m_CubeReflTexArray.NewFrame();
        }

        void InitAndClearBuffer(Camera camera, RenderLoop renderLoop)
        {
            // We clear only the depth buffer, no need to clear the various color buffer as we overwrite them.
            // Clear depth/stencil and init buffers
            {
                var cmd = new CommandBuffer();
                cmd.name = "InitGBuffers and clear Depth/Stencil";

                // Init buffer
                // With scriptable render loop we must allocate ourself depth and color buffer (We must be independent of backbuffer for now, hope to fix that later).
                // Also we manage ourself the HDR format, here allocating fp16 directly.
                // With scriptable render loop we can allocate temporary RT in a command buffer, they will not be release with ExecuteCommandBuffer
                // These temporary surface are release automatically at the end of the scriptable renderloop if not release explicitly
                int w = camera.pixelWidth;
                int h = camera.pixelHeight;

                cmd.GetTemporaryRT(m_CameraColorBuffer, w, h, 0, FilterMode.Point, RenderTextureFormat.ARGBHalf, RenderTextureReadWrite.Linear);
                cmd.GetTemporaryRT(m_CameraDepthBuffer, w, h, 24, FilterMode.Point, RenderTextureFormat.Depth);
                if (!debugParameters.useForwardRenderingOnly)
                {
                    m_gbufferManager.InitGBuffers(w, h, cmd);
                }
                renderLoop.ExecuteCommandBuffer(cmd);
                cmd.Dispose();

                Utilities.SetRenderTarget(renderLoop, m_CameraColorBufferRT, m_CameraDepthBufferRT, ClearFlag.ClearDepth);
            }


            // TEMP: As we are in development and have not all the setup pass we still clear the color in emissive buffer and gbuffer, but this will be removed later.

            // Clear HDR target
            {
                Utilities.SetRenderTarget(renderLoop, m_CameraColorBufferRT, m_CameraDepthBufferRT, ClearFlag.ClearColor, Color.black, "Clear HDR target");
            }


            // Clear GBuffers
            {
                Utilities.SetRenderTarget(renderLoop, m_gbufferManager.GetGBuffers(), m_CameraDepthBufferRT, ClearFlag.ClearColor, Color.black, "Clear GBuffer");
            }

            // END TEMP
        }

        void RenderOpaqueRenderList(CullResults cull, Camera camera, RenderLoop renderLoop, string passName, RendererConfiguration rendererConfiguration = 0)
        {
            if (!debugParameters.displayOpaqueObjects)
                return;

            var settings = new DrawRendererSettings(cull, camera, new ShaderPassName(passName))
            {
                rendererConfiguration = rendererConfiguration,
                sorting = { sortOptions = SortOptions.SortByMaterialThenMesh }
            };        
            settings.inputFilter.SetQueuesOpaque();
            renderLoop.DrawRenderers(ref settings);
        }

        void RenderTransparentRenderList(CullResults cull, Camera camera, RenderLoop renderLoop, string passName, RendererConfiguration rendererConfiguration = 0)
        {
            if (!debugParameters.displayTransparentObjects)
                return;

            var settings = new DrawRendererSettings(cull, camera, new ShaderPassName(passName))
            {
                rendererConfiguration = rendererConfiguration,
                sorting = { sortOptions = SortOptions.BackToFront }
            };
            settings.inputFilter.SetQueuesTransparent();
            renderLoop.DrawRenderers(ref settings);
        }

        void RenderDepthPrepass(CullResults cull, Camera camera, RenderLoop renderLoop)
        {
            // If we are forward only we will do a depth prepass
            // TODO: Depth prepass should be enabled based on light loop settings. LightLoop define if they need a depth prepass + forward only...
            if (!debugParameters.useDepthPrepass)
                return;

            // TODO: Must do opaque then alpha masked for performance! 
            // TODO: front to back for opaque and by materal for opaque tested when we split in two
            Utilities.SetRenderTarget(renderLoop, m_CameraDepthBufferRT, "Depth Prepass");
            RenderOpaqueRenderList(cull, camera, renderLoop, "DepthOnly");
        }

        void RenderGBuffer(CullResults cull, Camera camera, RenderLoop renderLoop)
        {
            if (debugParameters.useForwardRenderingOnly)
            {
                return ;
            }

            // setup GBuffer for rendering
            Utilities.SetRenderTarget(renderLoop, m_gbufferManager.GetGBuffers(), m_CameraDepthBufferRT, "GBuffer Pass");
            // render opaque objects into GBuffer
            RenderOpaqueRenderList(cull, camera, renderLoop, "GBuffer", Utilities.kRendererConfigurationBakedLighting);
        }

        // This pass is use in case of forward opaque and deferred rendering. We need to render forward objects before tile lighting pass
        void RenderForwardOpaqueDepth(CullResults cull, Camera camera, RenderLoop renderLoop)
        {
            // If we have render a depth prepass, no need for this pass
            if (debugParameters.useDepthPrepass)
                return;

            // TODO: Use the render queue index to only send the forward opaque!
            Utilities.SetRenderTarget(renderLoop, m_CameraDepthBufferRT, "Clear HDR target");
			RenderOpaqueRenderList(cull, camera, renderLoop, "DepthOnly");
        }

        void RenderDebugViewMaterial(CullResults cull, Camera camera, RenderLoop renderLoop)
        {
            // Render Opaque forward
            {
                Utilities.SetRenderTarget(renderLoop, m_CameraColorBufferRT, m_CameraDepthBufferRT, Utilities.kClearAll, Color.black, "DebugView Material Mode Pass");

                Shader.SetGlobalInt("_DebugViewMaterial", (int)debugParameters.debugViewMaterial);

                RenderOpaqueRenderList(cull, camera, renderLoop, "DebugViewMaterial");
            }

            // Render GBuffer opaque
            if (!debugParameters.useForwardRenderingOnly)
            {
                Vector4 screenSize = Utilities.ComputeScreenSize(camera);
                m_DebugViewMaterialGBuffer.SetVector("_ScreenSize", screenSize);
                m_DebugViewMaterialGBuffer.SetFloat("_DebugViewMaterial", (float)debugParameters.debugViewMaterial);

                // m_gbufferManager.BindBuffers(m_DebugViewMaterialGBuffer);
                // TODO: Bind depth textures
                var cmd = new CommandBuffer { name = "GBuffer Debug Pass" };
                cmd.Blit(null, m_CameraColorBufferRT, m_DebugViewMaterialGBuffer, 0);
                renderLoop.ExecuteCommandBuffer(cmd);
                cmd.Dispose();
            }

            // Render forward transparent
            {
                RenderTransparentRenderList(cull, camera, renderLoop, "DebugViewMaterial");
            }

            // Last blit
            {
                var cmd = new CommandBuffer { name = "Blit DebugView Material Debug" };
                cmd.Blit(m_CameraColorBufferRT, BuiltinRenderTextureType.CameraTarget);
                renderLoop.ExecuteCommandBuffer(cmd);
                cmd.Dispose();
            }
        }

        void RenderDeferredLighting(Camera camera, RenderLoop renderLoop)
        {
            if (debugParameters.useForwardRenderingOnly)
            {
                return ;
            }

            // Bind material data
            m_LitRenderLoop.Bind();

            m_SinglePassLightLoop.RenderDeferredLighting(camera, renderLoop, m_CameraColorBuffer);
          //  m_TilePassLightLoop.RenderDeferredLighting(camera, renderLoop, m_CameraColorBuffer);
        }

        void RenderSky(Camera camera, RenderLoop renderLoop)
        {
            m_SkyRenderer.RenderSky(camera, m_SkyParameters, m_CameraColorBufferRT, m_CameraDepthBufferRT, renderLoop);
        }

        void RenderForward(CullResults cullResults, Camera camera, RenderLoop renderLoop)
        {
            // Bind material data
            m_LitRenderLoop.Bind();

            Utilities.SetRenderTarget(renderLoop, m_CameraColorBufferRT, m_CameraDepthBufferRT, "Forward Pass");

            if (debugParameters.useForwardRenderingOnly)
            {
                RenderOpaqueRenderList(cullResults, camera, renderLoop, "Forward");
            }

            RenderTransparentRenderList(cullResults, camera, renderLoop, "Forward", Utilities.kRendererConfigurationBakedLighting);
        }

        void RenderForwardUnlit(CullResults cullResults, Camera camera, RenderLoop renderLoop)
        {
            // Bind material data
            m_LitRenderLoop.Bind();

            Utilities.SetRenderTarget(renderLoop, m_CameraColorBufferRT, m_CameraDepthBufferRT, "Forward Unlit Pass");
            RenderOpaqueRenderList(cullResults, camera, renderLoop, "ForwardUnlit");
            RenderTransparentRenderList(cullResults, camera, renderLoop, "ForwardUnlit");
        }

        void RenderVelocity(CullResults cullResults, Camera camera, RenderLoop renderLoop)
        {
            // warning CS0162: Unreachable code detected // warning CS0429: Unreachable expression code detected
#pragma warning disable 162, 429
            // If opaque velocity have been render during GBuffer no need to render it here
            if ((ShaderConfig.VelocityInGbuffer == 0) || debugParameters.useForwardRenderingOnly)
                return ;

            int w = camera.pixelWidth;
            int h = camera.pixelHeight;

            var cmd = new CommandBuffer { name = "Velocity Pass" };
            cmd.GetTemporaryRT(m_VelocityBuffer, w, h, 0, FilterMode.Point, Builtin.RenderLoop.GetVelocityBufferFormat(), Builtin.RenderLoop.GetVelocityBufferReadWrite());
            cmd.SetRenderTarget(m_VelocityBufferRT, m_CameraDepthBufferRT);
            renderLoop.ExecuteCommandBuffer(cmd);
            cmd.Dispose();

            RenderOpaqueRenderList(cullResults, camera, renderLoop, "MotionVectors");
#pragma warning restore 162, 429
        }

        void RenderDistortion(CullResults cullResults, Camera camera, RenderLoop renderLoop)
        {
            int w = camera.pixelWidth;
            int h = camera.pixelHeight;

            var cmd = new CommandBuffer { name = "Distortion Pass" };
            cmd.GetTemporaryRT(m_DistortionBuffer, w, h, 0, FilterMode.Point, Builtin.RenderLoop.GetDistortionBufferFormat(), Builtin.RenderLoop.GetDistortionBufferReadWrite());
            cmd.SetRenderTarget(m_DistortionBufferRT, m_CameraDepthBufferRT);
            renderLoop.ExecuteCommandBuffer(cmd);
            cmd.Dispose();

            // Only transparent object can render distortion vectors
            RenderTransparentRenderList(cullResults, camera, renderLoop, "DistortionVectors");
        }


        void FinalPass(RenderLoop renderLoop)
        {
            // Those could be tweakable for the neutral tonemapper, but in the case of the LookDev we don't need that
            const float blackIn = 0.02f;
            const float whiteIn = 10.0f;
            const float blackOut = 0.0f;
            const float whiteOut = 10.0f;
            const float whiteLevel = 5.3f;
            const float whiteClip = 10.0f;
            const float dialUnits = 20.0f;
            const float halfDialUnits = dialUnits * 0.5f;

            // converting from artist dial units to easy shader-lerps (0-1)
            var tonemapCoeff1 = new Vector4((blackIn * dialUnits) + 1.0f, (blackOut * halfDialUnits) + 1.0f, (whiteIn / dialUnits), (1.0f - (whiteOut / dialUnits)));
            var tonemapCoeff2 = new Vector4(0.0f, 0.0f, whiteLevel, whiteClip / halfDialUnits);

            m_FinalPassMaterial.SetVector("_ToneMapCoeffs1", tonemapCoeff1);
            m_FinalPassMaterial.SetVector("_ToneMapCoeffs2", tonemapCoeff2);

            m_FinalPassMaterial.SetFloat("_EnableToneMap", debugParameters.enableTonemap ? 1.0f : 0.0f);
            m_FinalPassMaterial.SetFloat("_Exposure", debugParameters.exposure);

            var cmd = new CommandBuffer { name = "FinalPass" };

            // Resolve our HDR texture to CameraTarget.
            cmd.Blit(m_CameraColorBufferRT, BuiltinRenderTextureType.CameraTarget, m_FinalPassMaterial, 0);
            renderLoop.ExecuteCommandBuffer(cmd);
            cmd.Dispose();
        }

        // Function to prepare light structure for GPU lighting
        void PrepareLightsForGPU(CullResults cullResults, Camera camera, ref ShadowOutput shadowOutput, ref LightList lightList)
        {
            lightList.Clear();

            for (int lightIndex = 0, numLights = cullResults.visibleLights.Length; lightIndex < numLights; ++lightIndex)
            {
                var light = cullResults.visibleLights[lightIndex];

                // We only process light with additional data
                var additionalData = light.light.GetComponent<AdditionalLightData>();

                if (additionalData == null)
                {
                    Debug.LogWarning("Light entity detected without additional data, will not be taken into account " + light.light.name);
                    continue;
                }

                // Linear intensity calculation (different Unity 5.5)
                var lightColorR = light.light.intensity * Mathf.GammaToLinearSpace(light.light.color.r);
                var lightColorG = light.light.intensity * Mathf.GammaToLinearSpace(light.light.color.g);
                var lightColorB = light.light.intensity * Mathf.GammaToLinearSpace(light.light.color.b);

                if (light.lightType == LightType.Directional)
                {
                    if (lightList.directionalLights.Count >= k_MaxDirectionalLightsOnSCreen)
                        continue;

                    var directionalLightData = new DirectionalLightData();
                    // Light direction for directional and is opposite to the forward direction
                    directionalLightData.direction = -light.light.transform.forward;
                    directionalLightData.color = new Vector3(lightColorR, lightColorG, lightColorB);
                    directionalLightData.diffuseScale = additionalData.affectDiffuse ? 1.0f : 0.0f;
                    directionalLightData.specularScale = additionalData.affectSpecular ? 1.0f : 0.0f;
                    directionalLightData.cosAngle = 0.0f;
                    directionalLightData.sinAngle = 0.0f;
                    directionalLightData.shadowIndex = -1;

                    bool hasDirectionalShadows = light.light.shadows != LightShadows.None && shadowOutput.GetShadowSliceCountLightIndex(lightIndex) != 0;
                    bool hasDirectionalNotReachMaxLimit = lightList.directionalShadows.Count == 0; // Only one cascade shadow allowed

                    if (hasDirectionalShadows && hasDirectionalNotReachMaxLimit) // Note  < MaxShadows should be check at shadowOutput creation
                    {
                        // When we have a point light, we assumed that there is 6 consecutive PunctualShadowData
                        directionalLightData.shadowIndex = 0;

                        for (int sliceIndex = 0; sliceIndex < shadowOutput.GetShadowSliceCountLightIndex(lightIndex); ++sliceIndex)
                        {
                            DirectionalShadowData directionalShadowData = new DirectionalShadowData();

                            int shadowSliceIndex = shadowOutput.GetShadowSliceIndex(lightIndex, sliceIndex);
                            directionalShadowData.worldToShadow = shadowOutput.shadowSlices[shadowSliceIndex].shadowTransform.transpose; // Transpose for hlsl reading ?

                            directionalShadowData.bias = light.light.shadowBias;

                            lightList.directionalShadows.Add(directionalShadowData);
                        }

                        // Fill split information for shaders
                        for (int s = 0; s < k_MaxCascadeCount; ++s)
                        {
                            lightList.directionalShadowSplitSphereSqr[s] = shadowOutput.directionalShadowSplitSphereSqr[s];
                        }
                    }

                    lightList.directionalLights.Add(directionalLightData);
                    lightList.directionalCullIndices.Add(lightIndex);

                    continue;
                }

                // Note: LightType.Area is offline only, use for baking, no need to test it
                var lightData = new LightData();

                // Test whether we should treat this punctual light as an area light.
                // It's a temporary hack until the proper UI support is added.
                if (additionalData.archetype != LightArchetype.Punctual)
                {
                    // Early out if we reach the maximum
                    if (lightList.areaLights.Count >= k_MaxAreaLightsOnSCreen)
                        continue;

                    if (additionalData.archetype == LightArchetype.Rectangle)
                    {
                        lightData.lightType = GPULightType.Rectangle;
                    }
                    else
                    {
                        lightData.lightType = GPULightType.Line;
                    }
                }
                else
                {
                    if (lightList.punctualLights.Count >= k_MaxPunctualLightsOnSCreen)
                        continue;

                    switch (light.lightType)
                    {
                        case LightType.Directional: lightData.lightType = GPULightType.Directional; break;
                        case LightType.Spot: lightData.lightType = GPULightType.Spot; break;
                        case LightType.Point: lightData.lightType = GPULightType.Point; break;
                    }
                }

                lightData.positionWS = light.light.transform.position;
                lightData.invSqrAttenuationRadius = 1.0f / (light.range * light.range);

                lightData.color = new Vector3(lightColorR, lightColorG, lightColorB);
                
                lightData.forward = light.light.transform.forward; // Note: Light direction is oriented backward (-Z)
                lightData.up = light.light.transform.up;
                lightData.right = light.light.transform.right;

                if (lightData.lightType == GPULightType.Spot)
                {
                    var spotAngle = light.spotAngle;

                    var innerConePercent = additionalData.GetInnerSpotPercent01();
                    var cosSpotOuterHalfAngle = Mathf.Clamp(Mathf.Cos(spotAngle * 0.5f * Mathf.Deg2Rad), 0.0f, 1.0f);
                    var cosSpotInnerHalfAngle = Mathf.Clamp(Mathf.Cos(spotAngle * 0.5f * innerConePercent * Mathf.Deg2Rad), 0.0f, 1.0f); // inner cone

                    var val = Mathf.Max(0.001f, (cosSpotInnerHalfAngle - cosSpotOuterHalfAngle));
                    lightData.angleScale = 1.0f / val;
                    lightData.angleOffset = -cosSpotOuterHalfAngle * lightData.angleScale;
                }
                else
                {
                    // 1.0f, 2.0f are neutral value allowing GetAngleAnttenuation in shader code to return 1.0
                    lightData.angleScale = 1.0f;
                    lightData.angleOffset = 2.0f;
                }

                lightData.diffuseScale = additionalData.affectDiffuse ? 1.0f : 0.0f;
                lightData.specularScale = additionalData.affectSpecular ? 1.0f : 0.0f;
                lightData.shadowDimmer = additionalData.shadowDimmer;

                lightData.IESIndex = -1;
                lightData.cookieIndex = -1;
                lightData.shadowIndex = -1;

                bool hasCookie = light.light.cookie != null;
                if (hasCookie)
                {
                    if (light.lightType == LightType.Point)
                    {
                        lightData.cookieIndex = m_CubeCookieTexArray.FetchSlice(light.light.cookie);
                    }
                    else if (light.lightType == LightType.Spot)
                    {
                        lightData.cookieIndex = m_CookieTexArray.FetchSlice(light.light.cookie);
                    }
                }

                // Setup shadow data arrays
                bool hasShadows = light.light.shadows != LightShadows.None && shadowOutput.GetShadowSliceCountLightIndex(lightIndex) != 0;
                bool hasNotReachMaxLimit = lightList.punctualShadows.Count + (lightData.lightType == GPULightType.Point ? 6 : 1) <= k_MaxShadowOnScreen;

                if (hasShadows && hasNotReachMaxLimit) // Note  < MaxShadows should be check at shadowOutput creation
                {
                    // When we have a point light, we assumed that there is 6 consecutive PunctualShadowData
                    lightData.shadowIndex = lightList.punctualShadows.Count;

                    for (int sliceIndex = 0; sliceIndex < shadowOutput.GetShadowSliceCountLightIndex(lightIndex); ++sliceIndex)
                    {
                        PunctualShadowData punctualShadowData = new PunctualShadowData();

                        int shadowSliceIndex = shadowOutput.GetShadowSliceIndex(lightIndex, sliceIndex);
                        punctualShadowData.worldToShadow = shadowOutput.shadowSlices[shadowSliceIndex].shadowTransform.transpose; // Transpose for hlsl reading ?
                        punctualShadowData.lightType = lightData.lightType;

                        punctualShadowData.bias = light.light.shadowBias;

                        lightList.punctualShadows.Add(punctualShadowData);
                    }
                }

                lightData.size = new Vector2(additionalData.areaLightLength, additionalData.areaLightWidth);
                lightData.twoSided = additionalData.isDoubleSided;

                if (additionalData.archetype == LightArchetype.Punctual)
                {
                    lightList.punctualLights.Add(lightData);
                    lightList.punctualCullIndices.Add(lightIndex);
                }
                else
                {
                    // Area and line lights are both currently stored as area lights on the GPU.
                    lightList.areaLights.Add(lightData);
                    lightList.areaCullIndices.Add(lightIndex);
                }
            }

            for (int probeIndex = 0, numProbes = cullResults.visibleReflectionProbes.Length; probeIndex < numProbes; probeIndex++)
            {
                var probe = cullResults.visibleReflectionProbes[probeIndex];

                // If probe have not been rendered discard
                if (probe.texture == null)
                    continue;

                if (lightList.envLights.Count >= k_MaxEnvLightsOnSCreen)
                    continue;

                var envLightData = new EnvLightData();

                // CAUTION: localToWorld is the transform for the widget of the reflection probe. i.e the world position of the point use to do the cubemap capture (mean it include the local offset)
                envLightData.positionWS = probe.localToWorld.GetColumn(3);

                envLightData.envShapeType = EnvShapeType.None;

                // TODO: Support sphere in the interface
                if (probe.boxProjection != 0)
                {
                    envLightData.envShapeType = EnvShapeType.Box;
                }

                // remove scale from the matrix (Scale in this matrix is use to scale the widget)
                envLightData.right = probe.localToWorld.GetColumn(0);
                envLightData.right.Normalize();
                envLightData.up = probe.localToWorld.GetColumn(1);
                envLightData.up.Normalize();
                envLightData.forward = probe.localToWorld.GetColumn(2);
                envLightData.forward.Normalize();

                // Artists prefer to have blend distance inside the volume!
                // So we let the current UI but we assume blendDistance is an inside factor instead
                // Blend distance can't be larger than the max radius
                // probe.bounds.extents is BoxSize / 2
                float maxBlendDist = Mathf.Min(probe.bounds.extents.x, Mathf.Min(probe.bounds.extents.y, probe.bounds.extents.z));
                float blendDistance = Mathf.Min(maxBlendDist, probe.blendDistance);
                envLightData.innerDistance = probe.bounds.extents - new Vector3(blendDistance, blendDistance, blendDistance);

                envLightData.envIndex = m_CubeReflTexArray.FetchSlice(probe.texture);

                envLightData.offsetLS = probe.center; // center is misnamed, it is the offset (in local space) from center of the bounding box to the cubemap capture point
                envLightData.blendDistance = blendDistance;
                lightList.envLights.Add(envLightData);
                lightList.envCullIndices.Add(probeIndex);
            }

            // build per tile light lists           
            m_SinglePassLightLoop.PrepareLightsForGPU(cullResults, camera, m_lightList);
            //m_TilePassLightLoop.PrepareLightsForGPU(cullResults, camera, m_lightList);
        }

        void Resize(Camera camera)
        {
            if (camera.pixelWidth != m_WidthOnRecord || camera.pixelHeight != m_HeightOnRecord || m_TilePassLightLoop.NeedResize())
            {
                if (m_WidthOnRecord > 0 && m_HeightOnRecord > 0)
                {
                    m_TilePassLightLoop.ReleaseResolutionDependentBuffers();
                }

                m_TilePassLightLoop.AllocResolutionDependentBuffers(camera.pixelWidth, camera.pixelHeight);

                // update recorded window resolution
                m_WidthOnRecord = camera.pixelWidth;
                m_HeightOnRecord = camera.pixelHeight;
            }
        }

        public void PushGlobalParams(Camera camera, RenderLoop renderLoop, HDRenderLoop.LightList lightList)
        {
            //Shader.SetGlobalTexture("_CookieTextures", m_CookieTexArray.GetTexCache());
            //Shader.SetGlobalTexture("_CubeCookieTextures", m_CubeCookieTexArray.GetTexCache());
            Shader.SetGlobalTexture("_EnvTextures", m_CubeReflTexArray.GetTexCache());

            m_SinglePassLightLoop.PushGlobalParams(camera, renderLoop, lightList);
            m_TilePassLightLoop.PushGlobalParams(camera, renderLoop, lightList);
        }

        public override void Render(Camera[] cameras, RenderLoop renderLoop)
        {
            if (!m_LitRenderLoop.isInit)
            {
                m_LitRenderLoop.RenderInit(renderLoop);
            }

            // Do anything we need to do upon a new frame.
            NewFrame();

            // Set Frame constant buffer
            // TODO...

            foreach (var camera in cameras)
            {
                // Set camera constant buffer
                // TODO...

                CullingParameters cullingParams;
                if (!CullResults.GetCullingParameters(camera, out cullingParams))
                    continue;

                m_ShadowPass.UpdateCullingParameters(ref cullingParams);

                var cullResults = CullResults.Cull(ref cullingParams, renderLoop);

                Resize(camera);

                renderLoop.SetupCameraProperties(camera);

                InitAndClearBuffer(camera, renderLoop);

                RenderDepthPrepass(cullResults, camera, renderLoop);

                RenderGBuffer(cullResults, camera, renderLoop); 

                // For tile lighting with forward opaque
                //RenderForwardOpaqueDepth(cullResults, camera, renderLoop);

                if (debugParameters.debugViewMaterial != 0)
                {
                    RenderDebugViewMaterial(cullResults, camera, renderLoop);
                }
                else
                {
                    ShadowOutput shadows;
                    m_ShadowPass.Render(renderLoop, cullResults, out shadows);

                    renderLoop.SetupCameraProperties(camera); // Need to recall SetupCameraProperties after m_ShadowPass.Render

                    PrepareLightsForGPU(cullResults, camera, ref shadows, ref m_lightList);
                    //m_TilePassLightLoop.BuildGPULightLists(camera, renderLoop, m_lightList, m_CameraDepthBuffer);

                    PushGlobalParams(camera, renderLoop, m_lightList);

                    RenderDeferredLighting(camera, renderLoop);

                    RenderSky(camera, renderLoop);

                    RenderForward(cullResults, camera, renderLoop); // Note: We want to render forward opaque before RenderSky, then RenderTransparent - can only do that once we have material.SetPass feature...
                    RenderForwardUnlit(cullResults, camera, renderLoop);

                    RenderVelocity(cullResults, camera, renderLoop); // Note we may have to render velocity earlier if we do temporalAO, temporal volumetric etc... Mean we will not take into account forward opaque in case of deferred rendering ? 

                    // TODO: Check with VFX team.
                    // Rendering distortion here have off course lot of artifact.
                    // But resolving at each objects that write in distortion is not possible (need to sort transparent, render those that do not distort, then resolve, then etc...)
                    // Instead we chose to apply distortion at the end after we cumulate distortion vector and desired blurriness. This
                    // RenderDistortion(cullResults, camera, renderLoop);

                    FinalPass(renderLoop);
                }

                renderLoop.Submit();
            }

            // Post effects
        }

        #if UNITY_EDITOR
        public override UnityEditor.SupportedRenderingFeatures GetSupportedRenderingFeatures()
        {
            var features = new UnityEditor.SupportedRenderingFeatures
            {
                reflectionProbe = UnityEditor.SupportedRenderingFeatures.ReflectionProbe.Rotation
            };

            return features;
        }
        #endif
    }
}