meta VS shaders

I guess I'm confused which compiler to use. Is this by lock3 the "demo" implementation which is superseded by clang 15.0-reflection (godbolt says that's the compiler used). I'm using clang for now

Is it related to the "meta" branch or a completely independent work ? (https://github.com/lock3/meta/wiki)

then there's no pure C++ solution, you either have to use alternative compilers such as https://github.com/lock3/meta/wiki or Circle, or use an external reflection system such as Qt's moc

https://github.com/lock3/meta/wiki/Metaprogramming-Introductory-Tutorial for a fork of clang with the reflection & metaclass feature

and https://github.com/lock3/meta/wiki/Reflection-Introductory-Tutorial for a tutorial

yup, that would be the "CPPX" compiler developed for prototyping reflection and metaprogramming features, also available here

It may be close to a technical impossibility, but the Circle compiler by Sean Baxter is attempting it. That's based on an aggressive "de-pointerization" (see [1] in particular for details). There's also academic work[2] to compile C++ to shaders. I agree that it's an open question how well that will work out.

Also as pointed out elsethread, now that buffer device address is starting to land, the friction to compile pointer-intense C++ code should decrease even more. These are exciting times!

[1]: https://github.com/seanbaxter/shaders#approaching-circle-sha...

[2]: https://arxiv.org/abs/2109.14682

You can use circle c++ shader https://github.com/seanbaxter/shaders but it's limited to look linux afaik?

First we have Circle C++ shaders, which pretty much would tick all the boxes. Problem is it's closed source and only compiles host code on linux. Closed source isn't the biggest of issues actually, but prevents anyone from fixing the developers issue with interfacing with the windows ABI and getting the thing working on windows (which itself isn't something they are able to fix because windows doesn't provide the documentation to work with their ABI). However you could use it separately to compile your SPIR-V for windows since SPIR-V doesn't care about platform itself.

Yes, Vulkan GPU source is split, though technically in a way that makes it more similar to CUDA. Vulkan uses an intermediate format instead of consuming text code directly, meaning new features are easier to add and frontend code doesn't need to be passed to the vendors driver compiler. SPIR-V is like DXIL or PTX code for CUDA, basically LLVM IR for GPUs. The CUDA compiler compiles your device code into PTX code, and it's what enables you to have "non split" source code. There's even an option to have separate PTX code in CUDA. There are few projects that aim to bring Vulkan SPIR-V into source, including Rust GPU for rust (though it will still have to be in a separate file) and Circle C++ shader for C++.

My favorite use is putting user-defined attributes on data members, and using reflection to generate a UI to manipulate those values. I do it with these shadertoys:

https://github.com/seanbaxter/shaders#reflection-and-attribu...

Just mark your declarations up with custom attributes:

I'm confused what is novel about this paper. We already have unified shader programming with circle C++, with way more features, and instead of having an SPIR-V compiler, they made a source to source compiler... We have quite a few of those.

I think shader specialisation is handled pretty well in circle. Since you can essentially run arbitrary C++ code at compile time, selection and specialisation of a shader can even depend on hardware specific benchmarks. There is an extensive repo with examples here: https://github.com/seanbaxter/shaders. One example decodes a sprite sheet stored as a png at compile time and creates a specialised compute shader for it. You can also easily implement a control UI based on reflection of uniform shader parameters.

There's a project doing something similar for C++ called Circle which is pretty incredible. In its core Circle is an extension of standard C++ which adds a ton of metaprogramming facilities and other productivity enhancing features, things the base language sorely lacks like full compile-time execution of regular C++ code which lets you do anything you can normally do from runtime during compile-time (including file I/O and networking), reflection, typed enums, pattern matching, hygienic macros, list comprehensions and language-native ranges, first class paramater packs and much more.

I use them to automatically generate an ImGui interface for controlling a shadertoy here: https://github.com/seanbaxter/shaders/blob/master/README.md#user-attributes-and-dear-imgui