CrateApp.cs

using System.Collections.Generic;
using System.Linq;
using System.Threading;
using SharpDX;
using SharpDX.Direct3D;
using SharpDX.Direct3D12;
using SharpDX.DXGI;
using Resource = SharpDX.Direct3D12.Resource;
using ShaderResourceViewDimension = SharpDX.Direct3D12.ShaderResourceViewDimension;

namespace DX12GameProgramming
{
    public class CrateApp : D3DApp
    {
        private readonly List<FrameResource> _frameResources = new List<FrameResource>(NumFrameResources);
        private readonly List<AutoResetEvent> _fenceEvents = new List<AutoResetEvent>(NumFrameResources);
        private int _currFrameResourceIndex;

        private DescriptorHeap _srvDescriptorHeap;
        private DescriptorHeap[] _descriptorHeaps;

        private RootSignature _rootSignature;

        private readonly Dictionary<string, MeshGeometry> _geometries = new Dictionary<string, MeshGeometry>();
        private readonly Dictionary<string, Material> _materials = new Dictionary<string, Material>();
        private readonly Dictionary<string, Texture> _textures = new Dictionary<string, Texture>();
        private readonly Dictionary<string, ShaderBytecode> _shaders = new Dictionary<string, ShaderBytecode>();

        private PipelineState _opaquePso;

        private InputLayoutDescription _inputLayout;

        // List of all the render items.
        private readonly List<RenderItem> _allRitems = new List<RenderItem>();

        // Render items divided by PSO.
        private readonly Dictionary<RenderLayer, List<RenderItem>> _ritemLayers = new Dictionary<RenderLayer, List<RenderItem>>(1)
        {
            [RenderLayer.Opaque] = new List<RenderItem>()
        };

        private PassConstants _mainPassCB = PassConstants.Default;

        private Vector3 _eyePos;
        private Matrix _proj = Matrix.Identity;
        private Matrix _view = Matrix.Identity;

        private float _theta = 1.3f * MathUtil.Pi;
        private float _phi = 0.4f * MathUtil.Pi;
        private float _radius = 5.0f;

        private Point _lastMousePos;

        public CrateApp()
        {
            MainWindowCaption = "Crate";
        }

        private FrameResource CurrFrameResource => _frameResources[_currFrameResourceIndex];
        private AutoResetEvent CurrentFenceEvent => _fenceEvents[_currFrameResourceIndex];

        public override void Initialize()
        {
            base.Initialize();

            // Reset the command list to prep for initialization commands.
            CommandList.Reset(DirectCmdListAlloc, null);

            LoadTextures();
            BuildRootSignature();
            BuildDescriptorHeaps();
            BuildShadersAndInputLayout();
            BuildShapeGeometry();
            BuildMaterials();
            BuildRenderItems();
            BuildFrameResources();
            BuildPSOs();

            // Execute the initialization commands.
            CommandList.Close();
            CommandQueue.ExecuteCommandList(CommandList);

            // Wait until initialization is complete.
            FlushCommandQueue();
        }

        protected override void OnResize()
        {
            base.OnResize();

            // The window resized, so update the aspect ratio and recompute the projection matrix.
            _proj = Matrix.PerspectiveFovLH(MathUtil.PiOverFour, AspectRatio, 1.0f, 1000.0f);
        }

        protected override void Update(GameTimer gt)
        {
            UpdateCamera();

            // Cycle through the circular frame resource array.
            _currFrameResourceIndex = (_currFrameResourceIndex + 1) % NumFrameResources;

            // Has the GPU finished processing the commands of the current frame resource?
            // If not, wait until the GPU has completed commands up to this fence point.
            if (CurrFrameResource.Fence != 0 && Fence.CompletedValue < CurrFrameResource.Fence)
            {
                Fence.SetEventOnCompletion(CurrFrameResource.Fence, CurrentFenceEvent.SafeWaitHandle.DangerousGetHandle());
                CurrentFenceEvent.WaitOne();
            }

            UpdateObjectCBs();
            UpdateMaterialCBs();
            UpdateMainPassCB(gt);
        }

        protected override void Draw(GameTimer gt)
        {
            CommandAllocator cmdListAlloc = CurrFrameResource.CmdListAlloc;

            // Reuse the memory associated with command recording.
            // We can only reset when the associated command lists have finished execution on the GPU.
            cmdListAlloc.Reset();

            // A command list can be reset after it has been added to the command queue via ExecuteCommandList.
            // Reusing the command list reuses memory.
            CommandList.Reset(cmdListAlloc, _opaquePso);

            CommandList.SetViewport(Viewport);
            CommandList.SetScissorRectangles(ScissorRectangle);

            // Indicate a state transition on the resource usage.
            CommandList.ResourceBarrierTransition(CurrentBackBuffer, ResourceStates.Present, ResourceStates.RenderTarget);

            // Clear the back buffer and depth buffer.
            CommandList.ClearRenderTargetView(CurrentBackBufferView, Color.LightSteelBlue);
            CommandList.ClearDepthStencilView(DepthStencilView, ClearFlags.FlagsDepth | ClearFlags.FlagsStencil, 1.0f, 0);

            // Specify the buffers we are going to render to.
            CommandList.SetRenderTargets(CurrentBackBufferView, DepthStencilView);

            CommandList.SetDescriptorHeaps(1, _descriptorHeaps);

            CommandList.SetGraphicsRootSignature(_rootSignature);

            Resource passCB = CurrFrameResource.PassCB.Resource;
            CommandList.SetGraphicsRootConstantBufferView(2, passCB.GPUVirtualAddress);

            DrawRenderItems(CommandList, _ritemLayers[RenderLayer.Opaque]);

            // Indicate a state transition on the resource usage.
            CommandList.ResourceBarrierTransition(CurrentBackBuffer, ResourceStates.RenderTarget, ResourceStates.Present);

            // Done recording commands.
            CommandList.Close();

            // Add the command list to the queue for execution.
            CommandQueue.ExecuteCommandList(CommandList);

            // Present the buffer to the screen. Presenting will automatically swap the back and front buffers.
            SwapChain.Present(0, PresentFlags.None);

            // Advance the fence value to mark commands up to this fence point.
            CurrFrameResource.Fence = ++CurrentFence;

            // Add an instruction to the command queue to set a new fence point.
            // Because we are on the GPU timeline, the new fence point won't be
            // set until the GPU finishes processing all the commands prior to this Signal().
            CommandQueue.Signal(Fence, CurrentFence);
        }

        protected override void OnMouseDown(MouseButtons button, Point location)
        {
            base.OnMouseDown(button, location);
            _lastMousePos = location;
        }

        protected override void OnMouseMove(MouseButtons button, Point location)
        {
            if ((button & MouseButtons.Left) != 0)
            {
                // Make each pixel correspond to a quarter of a degree.
                float dx = MathUtil.DegreesToRadians(0.25f * (location.X - _lastMousePos.X));
                float dy = MathUtil.DegreesToRadians(0.25f * (location.Y - _lastMousePos.Y));

                // Update angles based on input to orbit camera around box.
                _theta += dx;
                _phi += dy;

                // Restrict the angle mPhi.
                _phi = MathUtil.Clamp(_phi, 0.1f, MathUtil.Pi - 0.1f);
            }
            else if ((button & MouseButtons.Right) != 0)
            {
                // Make each pixel correspond to a quarter of a degree.
                float dx = 0.005f * (location.X - _lastMousePos.X);
                float dy = 0.005f * (location.Y - _lastMousePos.Y);

                // Update the camera radius based on input.
                _radius += dx - dy;

                // Restrict the radius.
                _radius = MathUtil.Clamp(_radius, 3.0f, 15.0f);
            }

            _lastMousePos = location;
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                _srvDescriptorHeap?.Dispose();
                _opaquePso?.Dispose();
                _rootSignature?.Dispose();
                foreach (Texture texture in _textures.Values) texture.Dispose();
                foreach (FrameResource frameResource in _frameResources) frameResource.Dispose();
                foreach (MeshGeometry geometry in _geometries.Values) geometry.Dispose();
            }
            base.Dispose(disposing);
        }

        private void UpdateCamera()
        {
            // Convert Spherical to Cartesian coordinates.
            _eyePos.X = _radius * MathHelper.Sinf(_phi) * MathHelper.Cosf(_theta);
            _eyePos.Z = _radius * MathHelper.Sinf(_phi) * MathHelper.Sinf(_theta);
            _eyePos.Y = _radius * MathHelper.Cosf(_phi);

            // Build the view matrix.
            _view = Matrix.LookAtLH(_eyePos, Vector3.Zero, Vector3.Up);
        }

        private void UpdateObjectCBs()
        {
            foreach (RenderItem e in _allRitems)
            {
                // Only update the cbuffer data if the constants have changed.
                // This needs to be tracked per frame resource.
                if (e.NumFramesDirty > 0)
                {
                    var objConstants = new ObjectConstants
                    {
                        World = Matrix.Transpose(e.World),
                        TexTransform = Matrix.Transpose(e.TexTransform)
                    };
                    CurrFrameResource.ObjectCB.CopyData(e.ObjCBIndex, ref objConstants);

                    // Next FrameResource need to be updated too.
                    e.NumFramesDirty--;
                }
            }
        }

        private void UpdateMaterialCBs()
        {
            UploadBuffer<MaterialConstants> currMaterialCB = CurrFrameResource.MaterialCB;
            foreach (Material mat in _materials.Values)
            {
                // Only update the cbuffer data if the constants have changed. If the cbuffer
                // data changes, it needs to be updated for each FrameResource.
                if (mat.NumFramesDirty > 0)
                {
                    var matConstants = new MaterialConstants
                    {
                        DiffuseAlbedo = mat.DiffuseAlbedo,
                        FresnelR0 = mat.FresnelR0,
                        Roughness = mat.Roughness,
                        MatTransform = Matrix.Transpose(mat.MatTransform)
                    };

                    currMaterialCB.CopyData(mat.MatCBIndex, ref matConstants);

                    // Next FrameResource need to be updated too.
                    mat.NumFramesDirty--;
                }
            }
        }

        private void UpdateMainPassCB(GameTimer gt)
        {
            Matrix viewProj = _view * _proj;
            Matrix invView = Matrix.Invert(_view);
            Matrix invProj = Matrix.Invert(_proj);
            Matrix invViewProj = Matrix.Invert(viewProj);

            _mainPassCB.View = Matrix.Transpose(_view);
            _mainPassCB.InvView = Matrix.Transpose(invView);
            _mainPassCB.Proj = Matrix.Transpose(_proj);
            _mainPassCB.InvProj = Matrix.Transpose(invProj);
            _mainPassCB.ViewProj = Matrix.Transpose(viewProj);
            _mainPassCB.InvViewProj = Matrix.Transpose(invViewProj);
            _mainPassCB.EyePosW = _eyePos;
            _mainPassCB.RenderTargetSize = new Vector2(ClientWidth, ClientHeight);
            _mainPassCB.InvRenderTargetSize = 1.0f / _mainPassCB.RenderTargetSize;
            _mainPassCB.NearZ = 1.0f;
            _mainPassCB.FarZ = 1000.0f;
            _mainPassCB.TotalTime = gt.TotalTime;
            _mainPassCB.DeltaTime = gt.DeltaTime;
            _mainPassCB.AmbientLight = new Vector4(0.25f, 0.25f, 0.35f, 1.0f);
            _mainPassCB.Lights[0].Direction = new Vector3(0.57735f, -0.57735f, 0.57735f);
            _mainPassCB.Lights[0].Strength = new Vector3(0.6f);
            _mainPassCB.Lights[1].Direction = new Vector3(-0.57735f, -0.57735f, 0.57735f);
            _mainPassCB.Lights[1].Strength = new Vector3(0.3f);
            _mainPassCB.Lights[2].Direction = new Vector3(0.0f, -0.707f, -0.707f);
            _mainPassCB.Lights[2].Strength = new Vector3(0.15f);

            CurrFrameResource.PassCB.CopyData(0, ref _mainPassCB);
        }

        private void LoadTextures()
        {
            var woodCrateTex = new Texture
            {
                Name = "woodCrateTex",
                Filename = "Textures/WoodCrate01.dds"
            };
            woodCrateTex.Resource = TextureUtilities.CreateTextureFromDDS(Device, woodCrateTex.Filename);
            _textures[woodCrateTex.Name] = woodCrateTex;
        }

        private void BuildRootSignature()
        {
            var texTable = new DescriptorRange(DescriptorRangeType.ShaderResourceView, 1, 0);

            var descriptor1 = new RootDescriptor(0, 0);
            var descriptor2 = new RootDescriptor(1, 0);
            var descriptor3 = new RootDescriptor(2, 0);

            // Root parameter can be a table, root descriptor or root constants.
            // Perfomance TIP: Order from most frequent to least frequent.
            var slotRootParameters = new[]
            {
                new RootParameter(ShaderVisibility.Pixel, texTable),
                new RootParameter(ShaderVisibility.Vertex, descriptor1, RootParameterType.ConstantBufferView),
                new RootParameter(ShaderVisibility.All, descriptor2, RootParameterType.ConstantBufferView),
                new RootParameter(ShaderVisibility.All, descriptor3, RootParameterType.ConstantBufferView)
            };

            // A root signature is an array of root parameters.
            var rootSigDesc = new RootSignatureDescription(
                RootSignatureFlags.AllowInputAssemblerInputLayout,
                slotRootParameters,
                GetStaticSamplers());

            _rootSignature = Device.CreateRootSignature(rootSigDesc.Serialize());
        }

        private void BuildDescriptorHeaps()
        {
            //
            // Create the SRV heap.
            //
            var srvHeapDesc = new DescriptorHeapDescription
            {
                DescriptorCount = 1,
                Type = DescriptorHeapType.ConstantBufferViewShaderResourceViewUnorderedAccessView,
                Flags = DescriptorHeapFlags.ShaderVisible
            };
            _srvDescriptorHeap = Device.CreateDescriptorHeap(srvHeapDesc);
            _descriptorHeaps = new[] { _srvDescriptorHeap };

            //
            // Fill out the heap with actual descriptors.
            //
            var hDescriptor = _srvDescriptorHeap.CPUDescriptorHandleForHeapStart;

            Resource woodCrateTexture = _textures["woodCrateTex"].Resource;

            var srvDesc = new ShaderResourceViewDescription
            {
                // TODO: API suggestion: Expose DefaultShader4ComponentMapping through ShaderComponentMapping enumeration.
                // TODO: Turn from int to ShaderComponentMapping enum.
                Shader4ComponentMapping = D3DUtil.DefaultShader4ComponentMapping,
                Format = woodCrateTexture.Description.Format,
                Dimension = ShaderResourceViewDimension.Texture2D,
                Texture2D = new ShaderResourceViewDescription.Texture2DResource
                {
                    MostDetailedMip = 0,
                    MipLevels = woodCrateTexture.Description.MipLevels,
                    ResourceMinLODClamp = 0.0f
                }
            };

            Device.CreateShaderResourceView(woodCrateTexture, srvDesc, hDescriptor);
        }

        private void BuildShadersAndInputLayout()
        {
            _shaders["standardVS"] = D3DUtil.CompileShader("Shaders\\Default.hlsl", "VS", "vs_5_0");
            _shaders["opaquePS"] = D3DUtil.CompileShader("Shaders\\Default.hlsl", "PS", "ps_5_0");

            _inputLayout = new InputLayoutDescription(new[]
            {
                new InputElement("POSITION", 0, Format.R32G32B32_Float, 0, 0),
                new InputElement("NORMAL", 0, Format.R32G32B32_Float, 12, 0),
                new InputElement("TEXCOORD", 0, Format.R32G32_Float, 24, 0)
            });
        }

        private void BuildShapeGeometry()
        {
            GeometryGenerator.MeshData box = GeometryGenerator.CreateBox(1.0f, 1.0f, 1.0f, 3);

            var boxSubmesh = new SubmeshGeometry
            {
                IndexCount = box.Indices32.Count,
                StartIndexLocation = 0,
                BaseVertexLocation = 0
            };

            Vertex[] vertices = box.Vertices.Select(x => new Vertex
            {
                Pos = x.Position,
                Normal = x.Normal,
                TexC = x.TexC
            }).ToArray();

            short[] indices = box.GetIndices16().ToArray();

            var geo = MeshGeometry.New(Device, CommandList, vertices, indices, "boxGeo");

            geo.DrawArgs["box"] = boxSubmesh;

            _geometries[geo.Name] = geo;
        }

        private void BuildPSOs()
        {
            //
            // PSO for opaque objects.
            //

            var opaquePsoDesc = new GraphicsPipelineStateDescription
            {
                InputLayout = _inputLayout,
                RootSignature = _rootSignature,
                VertexShader = _shaders["standardVS"],
                PixelShader = _shaders["opaquePS"],
                RasterizerState = RasterizerStateDescription.Default(),
                BlendState = BlendStateDescription.Default(),
                DepthStencilState = DepthStencilStateDescription.Default(),
                SampleMask = int.MaxValue,
                PrimitiveTopologyType = PrimitiveTopologyType.Triangle,
                RenderTargetCount = 1,
                SampleDescription = new SampleDescription(MsaaCount, MsaaQuality),
                DepthStencilFormat = DepthStencilFormat
            };
            opaquePsoDesc.RenderTargetFormats[0] = BackBufferFormat;

            _opaquePso = Device.CreateGraphicsPipelineState(opaquePsoDesc);
        }

        private void BuildFrameResources()
        {
            for (int i = 0; i < NumFrameResources; i++)
            {
                _frameResources.Add(new FrameResource(Device, 1, _allRitems.Count, _materials.Count));
                _fenceEvents.Add(new AutoResetEvent(false));
            }
        }

        private void BuildMaterials()
        {
            AddMaterial(new Material
            {
                Name = "woodCrate",
                MatCBIndex = 0,
                DiffuseSrvHeapIndex = 0,
                DiffuseAlbedo = Color.White.ToVector4(),
                FresnelR0 = new Vector3(0.05f),
                Roughness = 0.2f
            });
        }

        private void AddMaterial(Material mat) => _materials[mat.Name] = mat;

        private void BuildRenderItems()
        {
            MeshGeometry geo = _geometries["boxGeo"];
            SubmeshGeometry submesh = geo.DrawArgs["box"];
            var boxRitem = new RenderItem
            {
                ObjCBIndex = 0,
                Mat = _materials["woodCrate"],
                Geo = geo,
                PrimitiveType = PrimitiveTopology.TriangleList,
                IndexCount = submesh.IndexCount,
                StartIndexLocation = submesh.StartIndexLocation,
                BaseVertexLocation = submesh.BaseVertexLocation
            };

            _allRitems.Add(boxRitem);
            // All the render items are opaque.
            _ritemLayers[RenderLayer.Opaque].AddRange(_allRitems);
        }

        private void DrawRenderItems(GraphicsCommandList cmdList, List<RenderItem> ritems)
        {
            int objCBByteSize = D3DUtil.CalcConstantBufferByteSize<ObjectConstants>();
            int matCBByteSize = D3DUtil.CalcConstantBufferByteSize<MaterialConstants>();

            Resource objectCB = CurrFrameResource.ObjectCB.Resource;
            Resource matCB = CurrFrameResource.MaterialCB.Resource;

            foreach (RenderItem ri in ritems)
            {
                cmdList.SetVertexBuffer(0, ri.Geo.VertexBufferView);
                cmdList.SetIndexBuffer(ri.Geo.IndexBufferView);
                cmdList.PrimitiveTopology = ri.PrimitiveType;

                GpuDescriptorHandle tex = _srvDescriptorHeap.GPUDescriptorHandleForHeapStart +
                    ri.Mat.DiffuseSrvHeapIndex * CbvSrvUavDescriptorSize;

                long objCBAddress = objectCB.GPUVirtualAddress + ri.ObjCBIndex * objCBByteSize;
                long matCBAddress = matCB.GPUVirtualAddress + ri.Mat.MatCBIndex * matCBByteSize;

                cmdList.SetGraphicsRootDescriptorTable(0, tex);
                cmdList.SetGraphicsRootConstantBufferView(1, objCBAddress);
                cmdList.SetGraphicsRootConstantBufferView(3, matCBAddress);

                cmdList.DrawIndexedInstanced(ri.IndexCount, 1, ri.StartIndexLocation, ri.BaseVertexLocation, 0);
            }
        }

        // Applications usually only need a handful of samplers. So just define them all up front
        // and keep them available as part of the root signature.
        private static StaticSamplerDescription[] GetStaticSamplers() => new[]
        {
            // PointWrap
            new StaticSamplerDescription(ShaderVisibility.All, 0, 0)
            {
                Filter = Filter.MinMagMipPoint,
                AddressUVW = TextureAddressMode.Wrap
            },
            // PointClamp
            new StaticSamplerDescription(ShaderVisibility.All, 1, 0)
            {
                Filter = Filter.MinMagMipPoint,
                AddressUVW = TextureAddressMode.Clamp
            },
            // LinearWrap
            new StaticSamplerDescription(ShaderVisibility.All, 2, 0)
            {
                Filter = Filter.MinMagMipLinear,
                AddressUVW = TextureAddressMode.Wrap
            },
            // LinearClamp
            new StaticSamplerDescription(ShaderVisibility.All, 3, 0)
            {
                Filter = Filter.MinMagMipLinear,
                AddressUVW = TextureAddressMode.Clamp
            },
            // AnisotropicWrap
            new StaticSamplerDescription(ShaderVisibility.All, 4, 0)
            {
                Filter = Filter.Anisotropic,
                AddressUVW = TextureAddressMode.Wrap,
                MipLODBias = 0.0f,
                MaxAnisotropy = 8
            },
            // AnisotropicClamp
            new StaticSamplerDescription(ShaderVisibility.All, 5, 0)
            {
                Filter = Filter.Anisotropic,
                AddressUVW = TextureAddressMode.Clamp,
                MipLODBias = 0.0f,
                MaxAnisotropy = 8
            }
        };
    }
}