HSH Shader Pipeline and Graphics Library

HSH is a modular shader compilation pipeline and run-time graphics library.

As an extended fork of LLVM's monorepo, HSH utilizes clang's parsing capabilities to transform C++17 semantics into complete Vulkan pipelines with HLSL as an intermediate shader language. The pipelines are encoded into C++ headers along with necessary metadata to create pipelines at run-time.

Shader pipelines are defined as C++ source files with one or more classes inheriting hsh::pipeline. The constructors of these pipeline classes contain statements using the builtin hsh types and intrinsic functions to define shader code in a language-agnostic manner. The constructor parameters may be declared with one or more resource handles; interfacing application uniform data and textures with the generated shaders. Along with the shader data in an API-ready representation, metadata is generated to establish vertex formats, sampler parameters, blend modes and other information used by the pipeline. Init-time declarations are generated forming an application-wide linked list of all compiled pipelines. This list is iterated and nodes are called to build all pipelines at run-time before actual rendering begins.

C++ templates may be used to define variations on a common shader model. All specializations of the template supply constant parameters that the shader template may use to vary specific aspects of its functionality (i.e. vertex format array sizes, control-flow selection of post-processing statements, blend modes, etc). For applications that cannot reasonably declare all possible template specializations explicitly, a profile-guided mode is available where non-constant values are bound to template parameters. Rendering is not available in this profiling mode. Instead, applications are expected to bind every possible pipeline specialization (based on all potential graphics resources or other artistic information) and exit. A header file of these unique specializations is emitted. Therefore, all pipelines can be compiled offline as long as the application can operate as an enumerating pipeline bind tool. Online pipeline compilation is currently outside the scope of hsh.

hshgen Build Tool

Found at clang/tools/hshgen/hshgen.cpp and clang/lib/Hsh/HshGenerator.cpp

This compile-time tool is used to generate shader code and pipeline metadata headers (.hshhead) from C++ files. When combined with the supplied CMake package, applications can easily integrate hshgen on a per-source-file basis.

libhsh Run-time Library

Found at libhsh

The offline preparation of hshgen is applied at run-time via the header-only libhsh. This library serves as a lightweight wrapper around the Vulkan graphics API. Types and constructs are provided to easily set up a rendering loop and resource ownership model.

Getting Started with HSH

In general, the build process of hsh is the same as vanilla LLVM. Build targets of interest include:

Target	Description
hshgen	Compile-time hshhead generator tool
check-hsh	Regression tests for verifying translated source code
install-distribution	Installs a minimal hsh distribution with hshgen and libhsh headers

The original README contains detailed instructions on the build workflow as follows:

The LLVM Compiler Infrastructure

This directory and its sub-directories contain source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.

The README briefly describes how to get started with building LLVM. For more information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.

Getting Started with the LLVM System

Taken from https://llvm.org/docs/GettingStarted.html.

Overview

Welcome to the LLVM project!

The LLVM project has multiple components. The core of the project is itself called "LLVM". This contains all of the tools, libraries, and header files needed to process intermediate representations and converts it into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer. It also contains basic regression tests.

C-like languages use the Clang front end. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.

Other components include: the libc++ C++ standard library, the LLD linker, and more.

Getting the Source Code and Building LLVM

The LLVM Getting Started documentation may be out of date. The Clang Getting Started page might have more accurate information.

This is an example work-flow and configuration to get and build the LLVM source:

1. Checkout LLVM (including related sub-projects like Clang):

   • git clone https://github.com/llvm/llvm-project.git

   • Or, on windows, git clone --config core.autocrlf=false https://github.com/llvm/llvm-project.git

2. Configure and build LLVM and Clang:

   • cd llvm-project

   • mkdir build

   • cd build

   • cmake -G <generator> [options] ../llvm

     Some common build system generators are:

     • Ninja --- for generating Ninja build files. Most llvm developers use Ninja.
     • Unix Makefiles --- for generating make-compatible parallel makefiles.
     • Visual Studio --- for generating Visual Studio projects and solutions.
     • Xcode --- for generating Xcode projects.

     Some Common options:

     • -DLLVM_ENABLE_PROJECTS='...' --- semicolon-separated list of the LLVM sub-projects you'd like to additionally build. Can include any of: clang, clang-tools-extra, libcxx, libcxxabi, libunwind, lldb, compiler-rt, lld, polly, or debuginfo-tests.

       For example, to build LLVM, Clang, libcxx, and libcxxabi, use -DLLVM_ENABLE_PROJECTS="clang;libcxx;libcxxabi".

     • -DCMAKE_INSTALL_PREFIX=directory --- Specify for directory the full path name of where you want the LLVM tools and libraries to be installed (default /usr/local).

     • -DCMAKE_BUILD_TYPE=type --- Valid options for type are Debug, Release, RelWithDebInfo, and MinSizeRel. Default is Debug.

     • -DLLVM_ENABLE_ASSERTIONS=On --- Compile with assertion checks enabled (default is Yes for Debug builds, No for all other build types).

   • cmake --build . [-- [options] <target>] or your build system specified above directly.

     • The default target (i.e. ninja or make) will build all of LLVM.

     • The check-all target (i.e. ninja check-all) will run the regression tests to ensure everything is in working order.

     • CMake will generate targets for each tool and library, and most LLVM sub-projects generate their own check-<project> target.

     • Running a serial build will be slow. To improve speed, try running a parallel build. That's done by default in Ninja; for make, use the option -j NNN, where NNN is the number of parallel jobs, e.g. the number of CPUs you have.

   • For more information see CMake

Consult the Getting Started with LLVM page for detailed information on configuring and compiling LLVM. You can visit Directory Layout to learn about the layout of the source code tree.