RecursiveAI.OneShader.Build 0.1.0-preview.1

OneShader.Build

HLSL shaders compiled during dotnet build, with C# bindings generated from them. Put *.hlsl files in a project and reference this package: each shader is compiled to SPIR-V by OneShader, a HLSL compiler written in C# with no dependency beyond .NET itself. Shader errors are build errors on the HLSL line, and constant buffers, vertex inputs and resource bindings become C# types and constants laid out to match the compiled shader, so a CPU/GPU mismatch fails the build instead of the frame.

Preview. Version 0.1 targets Vulkan (SPIR-V). The API and the generated code may still change before 1.0.

Install

dotnet add package RecursiveAI.OneShader.Build --prerelease

Target framework net10.0. Build with the .NET SDK (dotnet build); Visual Studio's .NET Framework MSBuild cannot load the build task.

Quick start

Shaders/Sprite.hlsl:

cbuffer Frame : register(b0) { float4x4 ViewProjection; };
[[vk::binding(1)]] Texture2D<float4> Atlas;
[[vk::binding(2)]] SamplerState AtlasSampler;

struct VSIn
{
    float2 Position : POSITION;
    float2 Uv : TEXCOORD0;
    [[oneshader::format("unorm8x4")]] float4 Color : COLOR0;
};
struct VSOut { float4 Position : SV_Position; float2 Uv : TEXCOORD0; float4 Color : COLOR0; };

[shader("vertex")]
VSOut VSMain(VSIn i)
{
    VSOut o;
    o.Position = mul(ViewProjection, float4(i.Position, 0, 1));
    o.Uv = i.Uv;
    o.Color = i.Color;
    return o;
}

[shader("pixel")]
float4 PSMain(VSOut i) : SV_Target { return Atlas.Sample(AtlasSampler, i.Uv) * i.Color; }

After dotnet build, with no reflection and no file I/O at run time:

using MyGame.Shaders;   // <RootNamespace>.Shaders

ReadOnlySpan<byte> vs = Sprite.VSMain.SpirV;        // embedded SPIR-V
ReadOnlySpan<byte> ps = Sprite.PSMain.SpirV;
uint stride = Sprite.VSMain.Stride;                 // 20
foreach (var a in Sprite.VSMain.Inputs) { /* a.Location, a.Format (Float32x2, Unorm8x4, ...), a.Offset */ }

var frame = new Sprite.Frame { ViewProjection = camera };  // explicit layout, Size = 64
uint set = Sprite.Bindings.Atlas.Set, binding = Sprite.Bindings.Atlas.Binding;

A mistake in the shader is an ordinary build error:

Shaders/Sprite.hlsl(24,45): error OSH0300: 'Atlass' is not declared. Did you mean 'Atlas'?

What is generated

One static class per HLSL file (named after the file, in PascalCase), containing:

• one blittable struct per constant buffer, with field offsets equal to the compiled shader's; matrices are Matrix4x4 members where element (i, j) is HLSL's M[i][j];
• a struct per structured-buffer element type;
• Bindings: set, binding, count and kind of every resource, as constants;
• per entry point: stage, entry name, the SPIR-V bytes; for vertex shaders a Vertex struct, Stride and Inputs; for compute shaders the thread-group size.

Support types (ShaderStage, ResourceKind, VertexFormat, VertexAttribute, ResourceBinding) come from RecursiveAI.OneShader, so a rendering layer in another assembly can take them. When only these are used, trimming removes the compiler from a NativeAOT app.

Item metadata: EntryPoints, Defines, IncludeDirectories, Namespace, ClassName. Properties: EnableDefaultOneShaderItems, OneShaderNamespace, OneShaderDefines, OneShaderIncludeDirectories. Shaders are recompiled only when they, a file they include, or the options change; the output is deterministic.

What works in 0.1

• Vertex, pixel and compute shaders in modern HLSL (Shader Model 6 style, HLSL 2021): structs, functions, constant buffers, textures and samplers, structured and byte-address buffers, storage images, groupshared memory, barriers and atomics, the preprocessor.
• SPIR-V for Vulkan 1.2, validated with spirv-val, and checked by running each shader in its test corpus on a GPU against the same shader compiled by DXC.
• Buffer layouts and descriptor bindings follow the conventions DXC uses for Vulkan, so existing shaders keep their layouts.

Known limits

• SPIR-V only. Metal (MSL) and WebGPU (WGSL) output are planned.
• Resources are single (Count == 1); resource arrays are not supported yet.
• HLSL templates, struct member functions, operator overloads and wave intrinsics report "not supported yet".
• dotnet build only (not Visual Studio's .NET Framework MSBuild).

License

MIT OR Apache-2.0, at your option. Copyright © Recursive AI, LLC.