SpirvCrossDll.dll

To build SpirvCrossDll.dll

Run cmake . in root dir to create Visual Studio project files (tested on Visual Studio 2019) - requires MSVC v143 C++ x64/x86 build tools (comes with Windows SDK)

Open ./SPIRV-Cross.sln

Run Build solution Release version

Then add existing project /SpirvCrossDll/SpirvCrossDll.vcxproj

Build SpirvCrossDll project, dll compiles to /x64/Release/SpirvCrossDll.dll.

Alternatively download the dll here https://github.com/robert-hoff/SPIRV-Cross/blob/spirvdll/SpirvCrossDll.dll

Including in C# project

Copy SpirvCrossDll.dll into C# project and add it as a reference.

Create the following method.

[DllImport("SpirvCrossDll.dll")]
private static extern IntPtr CreateSpirvDecompiler();

[DllImport("SpirvCrossDll.dll")]
private static extern int PushUInt32(IntPtr decompiler, UInt32 val);

[DllImport("SpirvCrossDll.dll")]
private static extern char Parse(IntPtr decompiler);

[DllImport("SpirvCrossDll.dll")]
private static extern int GetDataLength(IntPtr decompiler);

[DllImport("SpirvCrossDll.dll")]
private static extern char GetChar(IntPtr decompiler, int i);

private static string DecompileSpirv(byte[] spirv_databytes)
{
    IntPtr decompiler = CreateSpirvDecompiler();
    for (int i = 0; i < spirv_databytes.Length; i += 4)
    {
        uint b0 = (uint)spirv_databytes[i + 0];
        uint b1 = (uint)spirv_databytes[i + 1];
        uint b2 = (uint)spirv_databytes[i + 2];
        uint b3 = (uint)spirv_databytes[i + 3];
        uint nextUInt32 = b3 + (b2 << 8) + (b1 << 16) + (b0 << 24);
        PushUInt32(decompiler, nextUInt32);
    }
    Parse(decompiler);
    int len = GetDataLength(decompiler);
    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < len; i++)
    {
        char c = GetChar(decompiler, i);
        sb.Append(c);
    }
    return sb.ToString();
}

Call DecompileSpirv(byte[] spirv_databytes) spirv bytecode will be decompiled into a GLSL string.

Example use

With VRF

string HLALYX_VULKAN_SHADERS_VPK = "[hlvr-dir]/game/hlvr/shaders_vulkan_dir.vpk";
string TARGET_VCS_FILE = "/shaders/vfx/solidcolor_vulkan_50_vs.vcs";
var package = new SteamDatabase.ValvePak.Package();
package.Read(HLALYX_VULKAN_SHADERS_VPK);
package.ReadEntry(package.FindEntry(TARGET_VCS_FILE), out byte[] vcsBytes);
ShaderFile shaderFile = new ShaderFile();
shaderFile.Read(TARGET_VCS_FILE, new MemoryStream(vcsBytes));
VulkanSource vulkanSource = (VulkanSource) shaderFile.GetZFrameFile(0).gpuSources[0];
byte[] spirvBytes = vulkanSource.GetSpirvBytes();
string decompiledSpirv = DecompileSpirv(spirvBytes);

With Asset Ripper

Intercept Spirv data in ShaderVulkanExporter.ExportSnippet(TextWriter writer, Stream stream, int offset, int size) In the statement

if (SmolvDecoder.Decode(stream, size, decodedStream))
{
  // decodedStream is the spirv encoding
}

Run

byte[] spirvBytes = decodedStream.ToArray();
string decompiledSpirv = DecompileSpirv(spirvBytes);

Sample output

Game Ballistic Overkill (Unity), Ballistic/UI/BloodSplatter vulkan-shader[0]

#version 450

layout(binding = 0, std140) uniform _18_20
{
    vec4 _m0[4];
    vec4 _m1[4];
    vec4 _m2;
} _20;

layout(location = 0) in vec4 _11;
layout(location = 0) out vec2 vs_TEXCOORD0;
layout(location = 2) in vec2 _86;
layout(location = 1) out vec4 _96;
layout(location = 1) in vec4 _97;
vec4 _9;
vec4 _48;

void main()
{
    _9 = _11.yyyy * _20._m0[1];
    _9 = (_20._m0[0] * _11.xxxx) + _9;
    _9 = (_20._m0[2] * _11.zzzz) + _9;
    _9 += _20._m0[3];
    _48 = _9.yyyy * _20._m1[1];
    _48 = (_20._m1[0] * _9.xxxx) + _48;
    _48 = (_20._m1[2] * _9.zzzz) + _48;
    gl_Position = (_20._m1[3] * _9.wwww) + _48;
    vs_TEXCOORD0 = (_86 * _20._m2.xy) + _20._m2.zw;
    _96 = _97;
    gl_Position.y = -gl_Position.y;
}