SPIRV-Cross VS ssgl

There also exists something like SPIRV-Cross which promises to be able to generate code from the SPIRV intermediate representation into Metal and all versions of GLSL and HLSL. I am not sure really how good it is at this point, but going forward we might start to see more high-level shader languages, that compile to SPRIV and then from there to the myriad of different shader formats different platforms expect.

If you have shaders, I believe you can use SPIRV-Cross to generate GLSL, which you can probably get to pass as OpenCL C with just a bunch of macro tweaks, or at worst some small changes to spv-cross.

Regarding reflection, here is a guide: https://github.com/KhronosGroup/SPIRV-Cross/wiki/Reflection-API-user-guide

I am working on an engine that targets Vulkan and Metal. I'm at the point now where I want to be able to dynamically update my shader at runtime to suit the type of data being sent in for drawing. I am currently using offline compilation for my GLSL (for Vulkan) and MSL (for Metal) shaders. What are your workflows for situations like this? For those using tools like SPIR-V Cross and shaderc, what has your experience been with these tools keeping up to date with the latest features in the specs?

For cross-platform support look at WebGPU and Vulkan (e.g,: [0] [1]. Essentially, you would need to write the func in WGSL or GLSL, HLSL or MSL. Each of these can be cross-compiled to SPIR-V (what Vulkan needs) with cross-compilers such as spirv-cross and naga.

Just for reference, the library I'm using (both for compiling the shaders and for reflection), is SPIRV-Cross by the Khronos Group and here you have the docs for the reflection API. I wanted to check out `glslang` but honestly this one so far has worked like a charm.

Aside from SPIRV-Reflect, if you're using SPIRV-cross to cross compile your shaders, there is also a --reflect arg you can pass which spits out reflection info in JSON format. We already need to cross compile from spirv, so it just removes a tool in the chain to depend on.

For your own engine, use the format your API uses. If you need crossplatformness, there is a new path available. Write your shaders in a language that compiles to SPIR-V (HLSL/GLSL are the most obvious languages), and then use SPIR-V Cross to compile the SPIR-V back to HLSL/GLSL for other API to consume.

It's here. I made a post about it too, there's some details in the comments on how this works.

Here I'm doing GLSL and running it via OpenGL on top of my own helper library (the main branch of the code repo explains it pretty well). For me it's the easiest way to code for a GPU by a wide margin, but I guess that's to be expected. For performance, the most important things here are using shared memory and persistent threads so there are less global reads and especially atomics (I wanted to do a local reduction on the end result but for whatever reason subgroup operations don't work on 64-bit integers and I didn't bother to write it out with shared memory)

Some of it is fine-grained control, some is how it’s nice to be able to treat shaders as separate entities, some is just different preference. But no actual limitation, in fact I built a thing for that on top of OpenGL.

Include is probably your best bet there. Personally I use this system that I made, which borrows the single source programming model from CUDA so that shaders are just reinterpreted C++ code that can sit within the rest of the program. This means I can call the same functions from C++ and the shaders, and includes work just like any other includes.

I also already have a library that gives compile time errors, by having the shaders just be a part of the C++ program :) This would also benefit slightly from having embedded files, as I wouldn't need to do the runtime hacks that are currently in place.

As a side note, you may be interested in this library that someone posted on /r/GraphicsProgramming awhile ago. Haven't used it, but it seems like it might fit in with your general design philosophy.

Because mine is the most faithful reproduction of GLSL I've seen. Almost all features work the same in C++ as they do in shaders -- the notable difference is that you can't pass swizzles by reference, and inout arguments have to be defined with a slightly wonky syntax.

The culmination of my attempts at wrapping OpenGL is ssgl, which foregoes basically all binding and lets you write shaders along C++ with semi-automatic lambda capture. The underlying implementation is filled with dragons, but from personal experience it's just bonkers how much nicer it is to work with compared to any other approach I've used.

I have a library that due to its nature (it defines a domain-specific language within C++) has to define macros for a bunch of words that some standard headers use as variable names. This causes the standard headers to completely break if my library headers are included before them, and the errors are less than intuitive. Is there a simple way to produce a meaningful error (like "library header must be included last") if a standard header is included after the library headers? Googling didn't help much, and at a quick glance standard headers don't appear to contain too many extremely common names that I could #define to static_assert or something. I'm fine with the sensible error being limited to a few of the big standard implementations, so the option of just going through the headers and finding enough such names is doable, but it'd be nice to have a cleaner solution.

Yeah, the state machine aspect does make debugging cumbersome, and it's very easy to forget some option in the wrong setting. But I don't fully agree with "a collection of spells", I think the steps to achieve something are (mostly) pretty straight forward. Though maybe memories go sweeter with time, I haven't written any binding code after making ssgl :-)