[Rendering] Reuse transfer buffers;

LittleCodingFox · LittleCodingFox · commit b36e465d7a99 · 2025-12-17T03:09:15.000Z
diff --git a/Engine/Staple.Core/Rendering/Mesh/MeshRenderSystem.cs b/Engine/Staple.Core/Rendering/Mesh/MeshRenderSystem.cs
@@ -1,8 +1,6 @@
 ﻿using System;
 using System.Collections.Generic;
 using System.Numerics;
-using System.Reflection.Metadata;
-using System.Runtime.InteropServices;
 
 namespace Staple.Internal;
 
@@ -27,11 +25,12 @@ private class InstanceData
     {
         public ExpandableContainer<InstanceInfo> instanceInfos = new();
         public Matrix4x4[] transformMatrices = [];
-        public VertexBuffer instanceBuffer;
     }
 
     private readonly Dictionary<int, InstanceData> instanceCache = [];
 
+    private readonly Dictionary<int, VertexBuffer> instanceBuffers = [];
+
     private readonly Lazy<VertexLayout> instanceLayout = new(() =>
     {
         return VertexLayoutBuilder.CreateNew()
@@ -60,6 +59,27 @@ public void Prepare()
     }
     #endregion
 
+    private VertexBuffer GetInstanceBuffer(int count)
+    {
+        if (instanceBuffers.TryGetValue(count, out var buffer) && buffer.Disposed == false)
+        {
+            return buffer;
+        }
+
+        buffer = VertexBuffer.Create(new Matrix4x4[count], instanceLayout.Value, RenderBufferFlags.GraphicsRead);
+
+        if((buffer?.Disposed ?? true))
+        {
+            instanceBuffers.Remove(count);
+
+            return null;
+        }
+
+        instanceBuffers.AddOrSetKey(count, buffer);
+
+        return buffer;
+    }
+
     /// <summary>
     /// Renders a mesh
     /// </summary>
@@ -309,20 +329,20 @@ public void Submit()
                     contents.transformMatrices[i] = contents.instanceInfos.Contents[i].transform.Matrix;
                 }
 
-                if(contents.instanceBuffer == null)
-                {
-                    contents.instanceBuffer = VertexBuffer.Create(contents.transformMatrices, instanceLayout.Value, RenderBufferFlags.GraphicsRead);
-                }
-                else
+                var buffer = GetInstanceBuffer(contents.transformMatrices.Length);
+
+                if(buffer == null)
                 {
-                    contents.instanceBuffer.Update(contents.transformMatrices);
+                    continue;
                 }
 
-                if (contents.instanceBuffer != null)
+                buffer.Update(contents.transformMatrices);
+
+                if (buffer != null)
                 {
                     renderState.instanceCount = contents.transformMatrices.Length;
 
-                    renderState.ApplyStorageBufferIfNeeded("StapleInstancingTransforms", contents.instanceBuffer);
+                    renderState.ApplyStorageBufferIfNeeded("StapleInstancingTransforms", buffer);
 
                     RenderSystem.Submit(renderState, renderData.mesh.SubmeshTriangleCount(contents.instanceInfos.Contents[0].submeshIndex),
                         contents.instanceInfos.Length);
diff --git a/Engine/Staple.Core/Rendering/RenderSystem/Backend/Impls/SDLGPU/Commands/SDLGPUReadTextureCommand.cs b/Engine/Staple.Core/Rendering/RenderSystem/Backend/Impls/SDLGPU/Commands/SDLGPUReadTextureCommand.cs
@@ -19,20 +19,7 @@ public void Update(IRendererBackend rendererBackend)
             return;
         }
 
-        if (resource.transferBuffer != nint.Zero)
-        {
-            SDL.ReleaseGPUTransferBuffer(backend.device, resource.transferBuffer);
-
-            resource.transferBuffer = nint.Zero;
-        }
-
-        var info = new SDL.GPUTransferBufferCreateInfo()
-        {
-            Size = (uint)resource.length,
-            Usage = SDL.GPUTransferBufferUsage.Download,
-        };
-
-        resource.transferBuffer = SDL.CreateGPUTransferBuffer(backend.device, in info);
+        resource.transferBuffer = backend.GetTransferBuffer(true, resource.length);
 
         if (resource.transferBuffer == nint.Zero)
         {
diff --git a/Engine/Staple.Core/Rendering/RenderSystem/Backend/Impls/SDLGPU/Commands/SDLGPUUpdateIndexBufferCommand.cs b/Engine/Staple.Core/Rendering/RenderSystem/Backend/Impls/SDLGPU/Commands/SDLGPUUpdateIndexBufferCommand.cs
@@ -24,7 +24,6 @@ public void Update(IRendererBackend rendererBackend)
             if (buffer.buffer != nint.Zero)
             {
                 SDL.ReleaseGPUBuffer(backend.device, buffer.buffer);
-                SDL.ReleaseGPUTransferBuffer(backend.device, buffer.transferBuffer);
 
                 buffer.transferBuffer = nint.Zero;
                 buffer.buffer = nint.Zero;
@@ -60,13 +59,7 @@ public void Update(IRendererBackend rendererBackend)
                 return;
             }
 
-            var transferInfo = new SDL.GPUTransferBufferCreateInfo()
-            {
-                Size = (uint)data.Length,
-                Usage = SDL.GPUTransferBufferUsage.Upload,
-            };
-
-            buffer.transferBuffer = SDL.CreateGPUTransferBuffer(backend.device, in transferInfo);
+            buffer.transferBuffer = backend.GetTransferBuffer(false, data.Length);
 
             if (buffer.transferBuffer == nint.Zero)
             {
@@ -93,7 +86,7 @@ public void Update(IRendererBackend rendererBackend)
             return;
         }
 
-        var mapData = SDL.MapGPUTransferBuffer(backend.device, buffer.transferBuffer, false);
+        var mapData = SDL.MapGPUTransferBuffer(backend.device, buffer.transferBuffer, true);
 
         unsafe
         {
diff --git a/Engine/Staple.Core/Rendering/RenderSystem/Backend/Impls/SDLGPU/Commands/SDLGPUUpdateTextureCommand.cs b/Engine/Staple.Core/Rendering/RenderSystem/Backend/Impls/SDLGPU/Commands/SDLGPUUpdateTextureCommand.cs
@@ -21,18 +21,10 @@ public void Update(IRendererBackend rendererBackend)
         {
             if(resource.transferBuffer != nint.Zero)
             {
-                SDL.ReleaseGPUTransferBuffer(backend.device, resource.transferBuffer);
-
                 resource.transferBuffer = nint.Zero;
             }
 
-            var info = new SDL.GPUTransferBufferCreateInfo()
-            {
-                Size = (uint)data.Length,
-                Usage = SDL.GPUTransferBufferUsage.Upload,
-            };
-
-            resource.transferBuffer = SDL.CreateGPUTransferBuffer(backend.device, in info);
+            resource.transferBuffer = backend.GetTransferBuffer(false, data.Length);
 
             if (resource.transferBuffer == nint.Zero)
             {
@@ -55,7 +47,7 @@ public void Update(IRendererBackend rendererBackend)
             return;
         }
 
-        var mapData = SDL.MapGPUTransferBuffer(backend.device, resource.transferBuffer, false);
+        var mapData = SDL.MapGPUTransferBuffer(backend.device, resource.transferBuffer, true);
 
         unsafe
         {
diff --git a/Engine/Staple.Core/Rendering/RenderSystem/Backend/Impls/SDLGPU/Commands/SDLGPUUpdateVertexBufferCommand.cs b/Engine/Staple.Core/Rendering/RenderSystem/Backend/Impls/SDLGPU/Commands/SDLGPUUpdateVertexBufferCommand.cs
@@ -24,7 +24,6 @@ public void Update(IRendererBackend rendererBackend)
             if (buffer.buffer != nint.Zero)
             {
                 SDL.ReleaseGPUBuffer(backend.device, buffer.buffer);
-                SDL.ReleaseGPUTransferBuffer(backend.device, buffer.transferBuffer);
 
                 buffer.transferBuffer = nint.Zero;
                 buffer.buffer = nint.Zero;
@@ -60,13 +59,7 @@ public void Update(IRendererBackend rendererBackend)
                 return;
             }
 
-            var transferInfo = new SDL.GPUTransferBufferCreateInfo()
-            {
-                Size = (uint)data.Length,
-                Usage = SDL.GPUTransferBufferUsage.Upload,
-            };
-
-            buffer.transferBuffer = SDL.CreateGPUTransferBuffer(backend.device, in transferInfo);
+            buffer.transferBuffer = backend.GetTransferBuffer(false, data.Length);
 
             if (buffer.transferBuffer == nint.Zero)
             {
@@ -93,7 +86,7 @@ public void Update(IRendererBackend rendererBackend)
             return;
         }
 
-        var mapData = SDL.MapGPUTransferBuffer(backend.device, buffer.transferBuffer, false);
+        var mapData = SDL.MapGPUTransferBuffer(backend.device, buffer.transferBuffer, true);
 
         unsafe
         {
diff --git a/Engine/Staple.Core/Rendering/RenderSystem/Backend/Impls/SDLGPU/SDLGPURendererBackend+Buffers.cs b/Engine/Staple.Core/Rendering/RenderSystem/Backend/Impls/SDLGPU/SDLGPURendererBackend+Buffers.cs
@@ -5,6 +5,31 @@ namespace Staple.Internal;
 
 internal partial class SDLGPURendererBackend
 {
+    internal nint GetTransferBuffer(bool download, int length)
+    {
+        var key = new TransferBufferCacheKey(download, length);
+
+        if(cachedTransferBuffers.TryGetValue(key, out var buffer))
+        {
+            return buffer;
+        }
+
+        var transferInfo = new SDL.GPUTransferBufferCreateInfo()
+        {
+            Size = (uint)length,
+            Usage = download ? SDL.GPUTransferBufferUsage.Download : SDL.GPUTransferBufferUsage.Upload,
+        };
+
+        buffer = SDL.CreateGPUTransferBuffer(device, in transferInfo);
+
+        if (buffer != nint.Zero)
+        {
+            cachedTransferBuffers.Add(key, buffer);
+        }
+
+        return buffer;
+    }
+
     internal void ReleaseBufferResource(BufferResource resource)
     {
         if ((resource?.used ?? false) == false)
@@ -14,8 +39,6 @@ internal void ReleaseBufferResource(BufferResource resource)
 
         if (resource.transferBuffer != nint.Zero)
         {
-            SDL.ReleaseGPUTransferBuffer(device, resource.transferBuffer);
-
             resource.transferBuffer = nint.Zero;
         }
 
diff --git a/Engine/Staple.Core/Rendering/RenderSystem/Backend/Impls/SDLGPU/SDLGPURendererBackend+Textures.cs b/Engine/Staple.Core/Rendering/RenderSystem/Backend/Impls/SDLGPU/SDLGPURendererBackend+Textures.cs
@@ -25,8 +25,6 @@ internal void ReleaseTextureResource(TextureResource resource)
 
         if (resource.transferBuffer != nint.Zero)
         {
-            SDL.ReleaseGPUTransferBuffer(device, resource.transferBuffer);
-
             resource.transferBuffer = nint.Zero;
         }
 
diff --git a/Engine/Staple.Core/Rendering/RenderSystem/Backend/Impls/SDLGPU/SDLGPURendererBackend.cs b/Engine/Staple.Core/Rendering/RenderSystem/Backend/Impls/SDLGPU/SDLGPURendererBackend.cs
@@ -83,6 +83,17 @@ internal class ViewData
         public StapleFragmentRenderData fragmentData;
     }
 
+    private readonly struct TransferBufferCacheKey(bool download, int length)
+    {
+        public readonly bool download = download;
+        public readonly int length = length;
+
+        public override int GetHashCode()
+        {
+            return HashCode.Combine(download, length);
+        }
+    }
+
     internal class TransientEntry
     {
         public readonly List<byte> vertices = [];
@@ -158,13 +169,7 @@ public void CreateBuffers()
                     return;
                 }
 
-                var transferInfo = new SDL.GPUTransferBufferCreateInfo()
-                {
-                    Size = (uint)vertices.Count,
-                    Usage = SDL.GPUTransferBufferUsage.Upload,
-                };
-
-                var transferBuffer = SDL.CreateGPUTransferBuffer(backend.device, in transferInfo);
+                var transferBuffer = backend.GetTransferBuffer(false, vertices.Count);
 
                 if (transferBuffer == nint.Zero)
                 {
@@ -218,8 +223,6 @@ public void CreateBuffers()
                 };
 
                 SDL.UploadToGPUBuffer(backend.copyPass, in location, in region, false);
-
-                SDL.ReleaseGPUTransferBuffer(backend.device, transferBuffer);
             }
 
             if(indices.Count > 0)
@@ -239,13 +242,7 @@ public void CreateBuffers()
                     return;
                 }
 
-                var transferInfo = new SDL.GPUTransferBufferCreateInfo()
-                {
-                    Size = (uint)(indices.Count * sizeof(ushort)),
-                    Usage = SDL.GPUTransferBufferUsage.Upload,
-                };
-
-                var transferBuffer = SDL.CreateGPUTransferBuffer(backend.device, in transferInfo);
+                var transferBuffer = backend.GetTransferBuffer(false, indices.Count * sizeof(ushort));
 
                 if (transferBuffer == nint.Zero)
                 {
@@ -299,8 +296,6 @@ public void CreateBuffers()
                 };
 
                 SDL.UploadToGPUBuffer(backend.copyPass, in location, in region, false);
-
-                SDL.ReleaseGPUTransferBuffer(backend.device, transferBuffer);
             }
 
             if (uintIndices.Count > 0)
@@ -320,13 +315,7 @@ public void CreateBuffers()
                     return;
                 }
 
-                var transferInfo = new SDL.GPUTransferBufferCreateInfo()
-                {
-                    Size = (uint)(uintIndices.Count * sizeof(uint)),
-                    Usage = SDL.GPUTransferBufferUsage.Upload,
-                };
-
-                var transferBuffer = SDL.CreateGPUTransferBuffer(backend.device, in transferInfo);
+                var transferBuffer = backend.GetTransferBuffer(false, uintIndices.Count * sizeof(uint));
 
                 if (transferBuffer == nint.Zero)
                 {
@@ -386,8 +375,6 @@ public void CreateBuffers()
                 };
 
                 SDL.UploadToGPUBuffer(backend.copyPass, in location, in region, false);
-
-                SDL.ReleaseGPUTransferBuffer(backend.device, transferBuffer);
             }
         }
     }
@@ -458,6 +445,7 @@ public void Clear()
     private readonly Dictionary<VertexLayout, TransientEntry> transientBuffers = [];
     private readonly TextureResource[] textures = new TextureResource[ushort.MaxValue - 1];
     private readonly List<SDLGPUShaderProgram> shaders = [];
+    private readonly Dictionary<TransferBufferCacheKey, nint> cachedTransferBuffers = [];
     private RenderTarget currentRenderTarget;
 
     private bool iteratingCommands = false;

Original file line number	Diff line number	Diff line change
`@@ -24,7 +24,6 @@ public void Update(IRendererBackend rendererBackend)`
`24`	`24`	`if (buffer.buffer != nint.Zero)`
`25`	`25`	`{`
`26`	`26`	`SDL.ReleaseGPUBuffer(backend.device, buffer.buffer);`
`27`		`- SDL.ReleaseGPUTransferBuffer(backend.device, buffer.transferBuffer);`
`28`	`27`
`29`	`28`	`buffer.transferBuffer = nint.Zero;`
`30`	`29`	`buffer.buffer = nint.Zero;`
`@@ -60,13 +59,7 @@ public void Update(IRendererBackend rendererBackend)`
`60`	`59`	`return;`
`61`	`60`	`}`
`62`	`61`
`63`		`- var transferInfo = new SDL.GPUTransferBufferCreateInfo()`
`64`		`- {`
`65`		`- Size = (uint)data.Length,`
`66`		`- Usage = SDL.GPUTransferBufferUsage.Upload,`
`67`		`- };`
`68`		`-`
`69`		`- buffer.transferBuffer = SDL.CreateGPUTransferBuffer(backend.device, in transferInfo);`
	`62`	`+ buffer.transferBuffer = backend.GetTransferBuffer(false, data.Length);`
`70`	`63`
`71`	`64`	`if (buffer.transferBuffer == nint.Zero)`
`72`	`65`	`{`
`@@ -93,7 +86,7 @@ public void Update(IRendererBackend rendererBackend)`
`93`	`86`	`return;`
`94`	`87`	`}`
`95`	`88`
`96`		`- var mapData = SDL.MapGPUTransferBuffer(backend.device, buffer.transferBuffer, false);`
	`89`	`+ var mapData = SDL.MapGPUTransferBuffer(backend.device, buffer.transferBuffer, true);`
`97`	`90`
`98`	`91`	`unsafe`
`99`	`92`	`{`
Original file line number	Diff line number	Diff line change
`@@ -21,18 +21,10 @@ public void Update(IRendererBackend rendererBackend)`
`21`	`21`	`{`
`22`	`22`	`if(resource.transferBuffer != nint.Zero)`
`23`	`23`	`{`
`24`		`- SDL.ReleaseGPUTransferBuffer(backend.device, resource.transferBuffer);`
`25`		`-`
`26`	`24`	`resource.transferBuffer = nint.Zero;`
`27`	`25`	`}`
`28`	`26`
`29`		`- var info = new SDL.GPUTransferBufferCreateInfo()`
`30`		`- {`
`31`		`- Size = (uint)data.Length,`
`32`		`- Usage = SDL.GPUTransferBufferUsage.Upload,`
`33`		`- };`
`34`		`-`
`35`		`- resource.transferBuffer = SDL.CreateGPUTransferBuffer(backend.device, in info);`
	`27`	`+ resource.transferBuffer = backend.GetTransferBuffer(false, data.Length);`
`36`	`28`
`37`	`29`	`if (resource.transferBuffer == nint.Zero)`
`38`	`30`	`{`
`@@ -55,7 +47,7 @@ public void Update(IRendererBackend rendererBackend)`
`55`	`47`	`return;`
`56`	`48`	`}`
`57`	`49`
`58`		`- var mapData = SDL.MapGPUTransferBuffer(backend.device, resource.transferBuffer, false);`
	`50`	`+ var mapData = SDL.MapGPUTransferBuffer(backend.device, resource.transferBuffer, true);`
`59`	`51`
`60`	`52`	`unsafe`
`61`	`53`	`{`
Original file line number	Diff line number	Diff line change
`@@ -25,8 +25,6 @@ internal void ReleaseTextureResource(TextureResource resource)`
`25`	`25`
`26`	`26`	`if (resource.transferBuffer != nint.Zero)`
`27`	`27`	`{`
`28`		`- SDL.ReleaseGPUTransferBuffer(device, resource.transferBuffer);`
`29`		`-`
`30`	`28`	`resource.transferBuffer = nint.Zero;`
`31`	`29`	`}`
`32`	`30`