Set up initial skeleton for Frame Interpolation implementation

Runtime/FrameInterpolation/FrameInterpolation.cs

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+using System;
+using System.Runtime.InteropServices;
+
+namespace FidelityFX.FrameGen
+{
+    public static class FrameInterpolation
+    {
+        public struct ContextDescription
+        {
+            
+        }
+
+        // TODO: turn all of these into structs
+        public class DispatchDescription
+        {
+            
+        }
+
+        [Flags]
+        public enum InitializationFlags
+        {
+            EnableDepthInverted = 1 << 0,
+            EnableDepthInfinite = 1 << 1,
+            EnableHDRColorInput = 1 << 3,
+            EnableDisplayResolutionMotionVectors = 1 << 4,
+            EnableJitterMotionVectors = 1 << 5,
+            EnableAsyncSupport = 1 << 6,
+        }
+
+        [Flags]
+        public enum DispatchFlags
+        {
+            DrawDebugTearLines = 1 << 0,
+            DrawDebugResetIndicators = 1 << 1,
+            DrawDebugView = 1 << 2,
+        }
+
+        [Serializable, StructLayout(LayoutKind.Sequential)]
+        internal struct Constants
+        {
+            
+        }
+
+        [Serializable, StructLayout(LayoutKind.Sequential)]
+        internal struct InpaintingPyramidConstants
+        {
+            public uint mips;
+            public uint numWorkGroups;
+            public uint workGroupOffsetX;
+            public uint workGroupOffsetY;
+        }
+    }
+}

Runtime/FrameInterpolation/FrameInterpolationContext.cs

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+using System.Runtime.InteropServices;
+using UnityEngine;
+using UnityEngine.Profiling;
+using UnityEngine.Rendering;
+
+namespace FidelityFX.FrameGen
+{
+    public class FrameInterpolationContext
+    {
+        private FrameInterpolation.ContextDescription _contextDescription;
+
+        private FrameInterpolationPass _reconstructAndDilatePass;
+        private FrameInterpolationPass _setupPass;
+        private FrameInterpolationPass _reconstructPreviousDepthPass;
+        private FrameInterpolationPass _gameMotionVectorFieldPass;
+        private FrameInterpolationPass _opticalFlowVectorFieldPass;
+        private FrameInterpolationPass _disocclusionMaskPass;
+        private FrameInterpolationPass _scfiPass;
+        private FrameInterpolationPass _inpaintingPyramidPass;
+        private FrameInterpolationPass _inpaintingPass;
+        private FrameInterpolationPass _gameVectorFieldInpaintingPyramidPass;
+        private FrameInterpolationPass _debugViewPass;
+        
+        private readonly FrameInterpolationResources _resources = new FrameInterpolationResources();
+        
+        private ComputeBuffer _frameInterpolationConstantsBuffer;
+        private readonly FrameInterpolation.Constants[] _frameInterpolationConstantsArray = { new FrameInterpolation.Constants() };
+        private ref FrameInterpolation.Constants Constants => ref _frameInterpolationConstantsArray[0];
+        
+        private ComputeBuffer _spdConstantsBuffer;
+        private readonly FrameInterpolation.InpaintingPyramidConstants[] _spdConstantsArray = { new FrameInterpolation.InpaintingPyramidConstants() };
+        private ref FrameInterpolation.InpaintingPyramidConstants SpdConstants => ref _spdConstantsArray[0];
+        
+        private readonly CustomSampler _sampler = CustomSampler.Create("Frame Interpolation");
+        
+        public void Create(in FrameInterpolation.ContextDescription contextDescription)
+        {
+            _contextDescription = contextDescription;
+
+            _frameInterpolationConstantsBuffer = CreateConstantBuffer<FrameInterpolation.Constants>();
+            _spdConstantsBuffer = CreateConstantBuffer<FrameInterpolation.InpaintingPyramidConstants>();
+            
+            CreatePasses();
+        }
+
+        private void CreatePasses()
+        {
+            
+        }
+
+        public void Destroy()
+        {
+            DestroyPass(ref _debugViewPass);
+            DestroyPass(ref _gameVectorFieldInpaintingPyramidPass);
+            DestroyPass(ref _inpaintingPass);
+            DestroyPass(ref _inpaintingPyramidPass);
+            DestroyPass(ref _scfiPass);
+            DestroyPass(ref _disocclusionMaskPass);
+            DestroyPass(ref _opticalFlowVectorFieldPass);
+            DestroyPass(ref _gameMotionVectorFieldPass);
+            DestroyPass(ref _reconstructPreviousDepthPass);
+            DestroyPass(ref _setupPass);
+            DestroyPass(ref _reconstructAndDilatePass);
+            
+            _resources.Destroy();
+            
+            DestroyConstantBuffer(ref _spdConstantsBuffer);
+            DestroyConstantBuffer(ref _frameInterpolationConstantsBuffer);
+        }
+
+        public void Dispatch(CommandBuffer commandBuffer, FrameInterpolation.DispatchDescription dispatchDescription)
+        {
+            commandBuffer.BeginSample(_sampler);
+            
+            commandBuffer.EndSample(_sampler);
+        }
+        
+        private static ComputeBuffer CreateConstantBuffer<TConstants>() where TConstants: struct
+        {
+            return new ComputeBuffer(1, Marshal.SizeOf<TConstants>(), ComputeBufferType.Constant);
+        }
+        
+        private static void DestroyConstantBuffer(ref ComputeBuffer bufferRef)
+        {
+            if (bufferRef == null)
+                return;
+            
+            bufferRef.Release();
+            bufferRef = null;
+        }
+
+        private static void DestroyPass(ref FrameInterpolationPass pass)
+        {
+            if (pass == null)
+                return;
+            
+            pass.Dispose();
+            pass = null;
+        }
+    }
+}

Runtime/FrameInterpolation/FrameInterpolationPass.cs

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+using System;
+using UnityEngine;
+using UnityEngine.Profiling;
+using UnityEngine.Rendering;
+
+namespace FidelityFX.FrameGen
+{
+    internal abstract class FrameInterpolationPass: IDisposable
+    {
+        protected readonly FrameInterpolation.ContextDescription ContextDescription;
+        protected readonly FrameInterpolationResources Resources;
+        protected readonly ComputeBuffer Constants;
+        
+        protected ComputeShader ComputeShader;
+        protected int KernelIndex;
+        
+        private CustomSampler _sampler;
+        
+        protected FrameInterpolationPass(FrameInterpolation.ContextDescription contextDescription, FrameInterpolationResources resources, ComputeBuffer constants)
+        {
+            ContextDescription = contextDescription;
+            Resources = resources;
+            Constants = constants;
+        }
+
+        public virtual void Dispose()
+        {
+        }
+        
+        public void ScheduleDispatch(CommandBuffer commandBuffer, OpticalFlow.DispatchDescription dispatchParams, int frameIndex, int dispatchX, int dispatchY, int dispatchZ = 1)
+        {
+            commandBuffer.BeginSample(_sampler);
+            DoScheduleDispatch(commandBuffer, dispatchParams, frameIndex, dispatchX, dispatchY, dispatchZ);
+            commandBuffer.EndSample(_sampler);
+        }
+
+        protected abstract void DoScheduleDispatch(CommandBuffer commandBuffer, OpticalFlow.DispatchDescription dispatchParams, int frameIndex, int dispatchX, int dispatchY, int dispatchZ);
+
+        protected void InitComputeShader(string passName, ComputeShader shader)
+        {
+            if (shader == null)
+            {
+                throw new MissingReferenceException($"Shader for Frame Interpolation pass '{passName}' could not be loaded! Please ensure it is included in the project correctly.");
+            }
+
+            ComputeShader = shader;
+            KernelIndex = ComputeShader.FindKernel("CS");
+            _sampler = CustomSampler.Create(passName);
+            
+            // TODO: shader variants
+        }
+    }
+}

Runtime/FrameInterpolation/FrameInterpolationResources.cs

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+namespace FidelityFX.FrameGen
+{
+    internal class FrameInterpolationResources
+    {
+        public void Destroy()
+        {
+            
+        }
+    }
+}

Runtime/FrameInterpolation/FrameInterpolationShaderIDs.cs

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+using UnityEngine;
+
+namespace FidelityFX.FrameGen
+{
+    public static class FrameInterpolationShaderIDs
+    {
+        public static readonly int SrvInputDepth = Shader.PropertyToID("r_input_depth");
+        public static readonly int SrvInputMotionVectors = Shader.PropertyToID("r_input_motion_vectors");
+    }
+}