Is there a good HLSL to SPIR-V compiler?

Question

I'm writing a voxel engine in C++, and I'm implementing a Vulkan renderer. I've decided to write shaders in HLSL, and translate them via SPIRV-Cross. However, this brings me to a problem - glslang's HLSL compiler does not allow samplers. For example, this pixel shader:

uniform sampler2D tex;
float4 main(float2 uv : TEXCOORD0) : COLOR0 {
    return tex2D(tex, uv);
}

gives this compiler output:

Expected Sampled Image to be of type OpTypeSampledImage
  %19 = OpImageSampleImplicitLod %v4float %17 %18

I don't know if I should write my shaders in GLSL, or use a different library. Any help would be appreciated.

Does HLSL use `sampler2D` as a type? – Nicol Bolas Sep 12 '21 at 22:27 — Nicol Bolas, Sep 12 '21 at 22:27
@NicolBolas As far as I know, yes. – YodaSoda1219 Sep 12 '21 at 22:53 — YodaSoda1219, Sep 12 '21 at 22:53
@YodaSoda1219 Nicol is right, HLSL uses `SamplerState`. – Carsten Sep 13 '21 at 08:23 — Carsten, Sep 13 '21 at 08:23

score 3 · Accepted Answer · answered Oct 14 '21 at 23:43

The official DirectX Shader Compiler (that's the one for HLSL 6 and above, not the old DxCompiler) actually supports transforming HLSL into SPIR-V. See their wiki page about it for an explanaition on how to build the compiler with that feature enabled, and how to use it.

That said, uniform sampler2D tex; is actually not HLSL but GLSL code. In HLSL, you would write

SamplerState sampler;
Texture2D tex;
float4 main(float2 uv : TEXCOORD0) : COLOR0 {
    return tex.Sample(sampler, uv);
}

Is there a good HLSL to SPIR-V compiler?

1 Answers1