rust-gpu v0.3

The Khronos Sci-Fi helmet model. glTF model viewer created by @msiglreith using rust-gpu (Source)

Hello everyone, and welcome to the third release of rust-gpu! Our project aimed at making Rust a first class language and ecosystem for GPU programming. You can read more about why we at Embark started this project in the original announcement.

We're still not publishing releases to crates.io or distributing artefacts for rust-gpu, but we still wanted to highlight some of the changes that have been happening over the past couple of months. For more information on how to get started with using rust-gpu in your projects, be sure to check out the Rust-GPU Dev Guide! You can always add a git dependency in cargo to access spirv-builder.

[build-dependencies]
spirv-builder = { git = "https://github.com/EmbarkStudios/rust-gpu.git", branch = "main" }

While not a user facing feature, we are also proud to announce that we've also reached an important internal milestone in rust-gpu. We've now completely rewritten our GLSL shaders in our internal Ark project with Rust thanks to the improvements in this release! 🎉

rustc_codegen_spirv

• The biggest change to rust-gpu is the added ability to infer storage class types. This removes the need to call .load/.store on the storage class types, and allows you to use Deref/DerefMut to manipulate the inner type directly. This a huge improvement rust-gpu ergonomics, as well leading to more efficient code being generated with the removal of unneeded OpLoads and OpStores when using large types.

  use spirv_std::{glam::{Vec4, vec2}, storage_class::{Input, Output}};
  
  #[spirv(fragment)]
  pub fn main_fs(
      #[spirv(frag_coord)] in_frag_coord: Input<Vec4>,
      mut output: Output<Vec4>,
  ) {
      // Before
      let frag_coord = frag_coord.load();
      output.store(black_box(vec2(frag_coord.x, frag_coord.y)));
      // Now
      *output = black_box(vec2(in_frag_coord.x, in_frag_coord.y));
  }

• Initial support for Algebraic Data Type enums (e.g. Option<T>) has been added. This support is initially only provided for enums which have all scalar values in each variants (integers, floats, booleans). So for example Option<u32> works, but Option<Struct> doesn't work at the moment.
• You no longer need add #[allow(unused_attributes)] in front of #[spirv] attributes to remove warnings.
• You can now provide const arguments to asm!.
• rustc_codegen_spirv will now remove different OpNames that target the same ID. This should reduce the size of the generated SPIR-V binaries.
• rustc_codegen_spirv will now try to deduplicate generated OpVariables. This fixes certain issues with compiling rust-gpu SPIR-V on Android platforms.
• You can now set entry_point_name in entry point attributes to change the final name of an entry point. E.g. #[spirv(vertex(entry_point_name = "foo_bar"))]
• You can now add the #[spirv(unroll_loops)] attribute to functions, which tells rustc_codegen_spirv to annotate all loops inside with Unroll.

spirv-std

• Added a new arch module which provides an abstraction some basic SPIR-V instructions as free functions. The first iteration includes two functions.
  • vector_extract_dynamic (OpVectorExtractDynamic)
  • vector_insert_dynamic (OpVectorInsertDynamic)
• Added textures::StorageImage2d which is an image designed be read/written to without a Sampler.
• Added the spirv-std-macros crate for holding the spirv proc macro which acts as dummy macro to allow to use the spirv attribute on CPU code (has no affect on CPU code).
• Added the gpu_only proc macro, which allows you to mark a function as only runnable on GPU, it will still generate a callable function on the CPU side, but it will cause a panic when called.
• Added discard and demote_to_helper_invocation functions. Which correspond to discard in GLSL and HLSL respectively.
• Derivative is now implemented for glam::{Vec2, Vec3, Vec3A, Vec4}.
• Added the SampledImage type, which is an image already combined with a sampler.

spirv-builder

• You can now build your shaders in release mode with --release or with SpirvBuilder::release
• If you're using spirv-builder in your build script, you can add the following to your Cargo.toml to improve build times.

  [profile.dev.build-override]
  opt-level = 3
  
  [profile.release.build-override]
  opt-level = 3

Contributors

Thank you to all the contributors who helped make this release possible! 🎉

• @AidanConnelly
• @AnIrishDuck
• @adrianisuru
• @DGriffin91
• @DeanBDean
• @eddyb
• @Hentropy
• @khyperia
• @Jake-Shadle
• @Jasper-Bekkers
• @lcnr
• @lpil
• @msiglreith
• @repi
• @VZout
• @XAMPPRocky
• @zicklag