Use stack-backed scatter series pipeline layouts

Author: wieslawsoltes

src/ProGPU.Scene/Compositor.cs

@@ -1234,7 +1234,7 @@ private void InitializePipelinesAndBindGroups()
                 Span<VertexBufferLayout> scatterVertexLayouts = stackalloc VertexBufferLayout[1];
                 scatterVertexLayouts[0] = new VertexBufferLayout
                 {
-                    ArrayStride = 12,
+                    ArrayStride = (uint)Unsafe.SizeOf<Vector3>(),
                     StepMode = VertexStepMode.Instance,
                     AttributeCount = 2,
                     Attributes = scatterAttribsPtr

src/ProGPU.Scene/Extensions/GpuScatterSeriesExtensionPipeline.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Buffers;
 using System.Numerics;
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using Silk.NET.WebGPU;
 using Silk.NET.Core.Native;
@@ -300,29 +301,28 @@ public unsafe void Render(
             {
                 var shaderModule = compositor.PipelineCache.GetOrCreateShader("ChartScatterShader", ChartScatterShaderCode, "ChartScatter WGSL Shader");
 
-                var scatterAttribs = new VertexAttribute[]
+                Span<VertexAttribute> attrs = stackalloc VertexAttribute[2];
+                attrs[0] = new VertexAttribute { Format = VertexFormat.Float32x2, Offset = 0, ShaderLocation = 0 }; // center
+                attrs[1] = new VertexAttribute { Format = VertexFormat.Float32, Offset = 8, ShaderLocation = 1 }; // radiusPx
+                fixed (VertexAttribute* attrsPtr = attrs)
                 {
-                    new() { Format = VertexFormat.Float32x2, Offset = 0, ShaderLocation = 0 }, // center
-                    new() { Format = VertexFormat.Float32, Offset = 8, ShaderLocation = 1 }   // radiusPx
-                };
-                fixed (VertexAttribute* scatterAttribsPtr = scatterAttribs)
-                {
-                    var scatterLayoutDesc = new VertexBufferLayout
+                    Span<VertexBufferLayout> layouts = stackalloc VertexBufferLayout[1];
+                    layouts[0] = new VertexBufferLayout
                     {
-                        ArrayStride = 12,
+                        ArrayStride = (uint)Unsafe.SizeOf<Vector3>(),
                         StepMode = VertexStepMode.Instance,
                         AttributeCount = 2,
-                        Attributes = scatterAttribsPtr
+                        Attributes = attrsPtr
                     };
 
                     var pipeline = compositor.PipelineCache.GetOrCreateRenderPipeline(
                         isOffscreen ? "ChartScatter_Offscreen" : "ChartScatter",
                         shaderModule,
+                        layouts,
                         "vs_main",
                         "fs_main",
                         compositor.RenderFormat,
                         PrimitiveTopology.TriangleList,
-                        new[] { scatterLayoutDesc },
                         enableBlend: true,
                         sampleCount: isOffscreen ? 1u : 4u
                     );

src/ProGPU.Tests/DiagnosticsLoggingSourceTests.cs

@@ -793,6 +793,7 @@ public void EffectPipelineLayoutsUseStackBackedDescriptors()
         string acisSolid = ReadSource("src", "ProGPU.Scene", "Extensions", "AcisSolidExtensionPipeline.cs");
         string hatch = ReadSource("src", "ProGPU.Scene", "Extensions", "HatchExtensionPipeline.cs");
         string mesh3D = ReadSource("src", "ProGPU.Scene", "Extensions", "Mesh3DExtensionPipeline.cs");
+        string scatterSeries = ReadSource("src", "ProGPU.Scene", "Extensions", "GpuScatterSeriesExtensionPipeline.cs");
         string pipelineCache = ReadSource("src", "ProGPU.Backend", "RenderPipelineCache.cs");
 
         Assert.Contains("Span<VertexAttribute> vectorAttrs = stackalloc VertexAttribute[8];", compositor, StringComparison.Ordinal);
@@ -804,6 +805,7 @@ public void EffectPipelineLayoutsUseStackBackedDescriptors()
         Assert.Contains("Span<VertexBufferLayout> vertexLayouts = stackalloc VertexBufferLayout[1];", compositor, StringComparison.Ordinal);
         Assert.Contains("ArrayStride = (uint)Unsafe.SizeOf<VectorVertex>()", compositor, StringComparison.Ordinal);
         Assert.Contains("ArrayStride = (uint)Unsafe.SizeOf<GlyphInstance>()", compositor, StringComparison.Ordinal);
+        Assert.Contains("ArrayStride = (uint)Unsafe.SizeOf<Vector3>()", compositor, StringComparison.Ordinal);
         Assert.DoesNotContain("var vertexAttribs = new VertexAttribute[]", compositor, StringComparison.Ordinal);
         Assert.DoesNotContain("var textVertexAttribs = new VertexAttribute[]", compositor, StringComparison.Ordinal);
         Assert.DoesNotContain("var scatterAttribs = new VertexAttribute[]", compositor, StringComparison.Ordinal);
@@ -823,6 +825,7 @@ public void EffectPipelineLayoutsUseStackBackedDescriptors()
         AssertStackBackedLayout(acisSolid, 8, "VectorVertex");
         AssertStackBackedLayout(hatch, 8, "VectorVertex");
         AssertStackBackedLayout(mesh3D, 2, "GpuVertex3D");
+        AssertStackBackedLayout(scatterSeries, 2, "Vector3");
 
         Assert.Contains("ReadOnlySpan<VertexBufferLayout> vertexBufferLayouts", pipelineCache, StringComparison.Ordinal);
         Assert.Contains("fixed (VertexBufferLayout* pLayouts = vertexBufferLayouts)", pipelineCache, StringComparison.Ordinal);
@@ -841,7 +844,9 @@ static void AssertStackBackedLayout(string source, int attributeCount, string ve
             Assert.Contains($"Span<VertexAttribute> attrs = stackalloc VertexAttribute[{attributeCount}];", source, StringComparison.Ordinal);
             Assert.Contains("Span<VertexBufferLayout> layouts = stackalloc VertexBufferLayout[1];", source, StringComparison.Ordinal);
             Assert.Contains($"ArrayStride = (uint)Unsafe.SizeOf<{vertexType}>()", source, StringComparison.Ordinal);
+            Assert.DoesNotContain("new VertexAttribute[]", source, StringComparison.Ordinal);
             Assert.DoesNotContain("new VertexBufferLayout[]", source, StringComparison.Ordinal);
+            Assert.DoesNotContain("new[] {", source, StringComparison.Ordinal);
             Assert.DoesNotContain("Marshal.AllocHGlobal(Marshal.SizeOf<VertexAttribute>()", source, StringComparison.Ordinal);
             Assert.DoesNotContain("Marshal.FreeHGlobal((IntPtr)layouts[0].Attributes)", source, StringComparison.Ordinal);
         }