Sharp Shader

Write all of your cross-platform shaders in a single language. Use C# as an intermediate language for writing HLSL and GLSL shaders, saving you valuable development time.

Bytecode or Source Translator?

SharpShader is a source-to-source translator. This means that C# source is taken as input and the source of a chosen shader language is produced as output. The main advantage of this approach is that the bulk of shader optimization can be left to where it's done best, the native shader compilers. It also means that any future optimizations and changes made to native HLSL/GLSL compilers can instantly be leveraged without changing SharpShader's source code.

SharpShader's feature-set is based around HLSL, so you will find many that of the type and attribute names are similar, or identical to their HLSL counterparts.

Current Status

• It is possible to generate most forms of HLSL shader from C# source.
• [WIP] Include files are not supported yet
• [WIP] GLSL support is almost non-existant
• [WIP] A few elements of C# syntax are not supported yet, such as tuples and indexers.
• There is currently no way to target a specific shader model (or GLSL version).
• Lots of unfinished things!
• A lot of bugs. Probably!

Example

Here is a C# to HLSL example showing off what Sharp Shader is capable of so far.

C# source:

using SharpShader;

namespace SharpShaderSample
{
    class SampleTextureShader : CSharpShader
    {
        public struct VertexInput
        {
            [Semantic(SemanticType.Position, 0)]
            public Vector4 Position;

            [Semantic(SemanticType.TexCoord, 0)]
            public Vector2 UV;
        }

        public struct PixelInput
        {
            [Semantic(SemanticType.SV_Position)]
            public Vector4 Position;

            [Semantic(SemanticType.TexCoord)]
            public Vector2 UV;
        }

        [ConstantBuffer]
        [Register(0)]
        public struct CommonData
        {
            [PackOffset(0)]
            public Matrix4x4 View;

            [PackOffset(4)]
            public Matrix4x4 Projection;

            [PackOffset(8)]
            public Matrix4x4 ViewProjection;

            [PackOffset(12)]
            public Matrix4x4 InvViewProjection;
        }

        [ConstantBuffer]
        [Register(1)]
        public struct ObjectData
        {
            [PackOffset(0)]
            public Matrix4x4 Wvp;

            [PackOffset(4)]
            public Matrix4x4 World;
        }

        public ObjectData cbObject;

        [Register(0)]
        public Texture2D mapTexture, mapNormals, mapSpecular;

        [Register(0)]
        public TextureSampler texSampler;

        [VertexShader]
        public PixelInput VertexFunc(VertexInput input)
        {
            return new PixelInput()
            {
                Position = Mul(input.Position, cbObject.Wvp),
                UV = input.UV,
            };
        }

        [FragmentShader(SemanticFragmentOutputType.SV_Target)]
        public Vector4 FragFunc(PixelInput input)
        {
            return mapTexture.Sample(texSampler, input.UV);
        }
    }
}

The above gets turned into the following HLSL source:

struct VertexInput
{
	float4 Position : POSITION0;
	float2 UV : TEXCOORD0;
};

struct PixelInput
{
	float4 Position : SV_POSITION;
	float2 UV : TEXCOORD;
};

cbuffer CommonData : register(b0)
{
	float4x4 View : packoffset(c0);
	float4x4 Projection : packoffset(c4);
	float4x4 ViewProjection : packoffset(c8);
	float4x4 InvViewProjection : packoffset(c12);
}

cbuffer ObjectData : register(b1)
{
	float4x4 Wvp : packoffset(c0);
	float4x4 World : packoffset(c4);
}

Texture2D mapTexture : register(t0);

Texture2D mapNormals : register(t1);

Texture2D mapSpecular : register(t2);

SamplerState texSampler : register(s0);

PixelInput VertexFunc(VertexInput input)
{
	PixelInput ss_ret_0;
	ss_ret_0.Position = mul(input.Position, Wvp);
	ss_ret_0.UV = input.UV;
	return ss_ret_0;
}

float4 FragFunc(PixelInput input) : SV_TARGET
{
	return mapTexture.Sample(texSampler, input.UV);
}

It is worth noting that while the above C# code has defined Register and PackOffset attributes on almost every struct and field, it is not mandatory to do so. The absence of such attributes will also result in the associated HLSL being absent, as shown in the example below:

C#:

public TextureSampler texSampler;

HLSL:

SamplerState texSampler;

Future Goals

Right now, focus is on implementing support for the majority of C#, HLSL and GLSL features. However, there are plenty of other features to be implemented in the future:

• Provide a common set of math types that are usable by both C# applications and SharpShader
• SPIR-V support
• Metal Shader Language (MSL) support
• .NET Core support