| # SwiftShader | |
| [](https://opensource.org/licenses/Apache-2.0) | |
| Introduction | |
| ------------ | |
| SwiftShader[^1] is a high-performance CPU-based implementation[^2] of the Vulkan[^3] 1.3 graphics API. Its goal is to provide hardware independence for advanced 3D graphics. | |
| > NOTE: The [ANGLE](http://angleproject.org/) project can be used to achieve a layered implementation[^4] of OpenGL ES 3.1 (aka. "SwANGLE"). | |
| Building | |
| -------- | |
| SwiftShader libraries can be built for Windows, Linux, and macOS.\ | |
| Android and Chrome (OS) build environments are also supported. | |
| * **CMake** | |
| \ | |
| [Install CMake](https://cmake.org/download/) for Linux, macOS, or Windows and use either [the GUI](https://cmake.org/runningcmake/) or run the following terminal commands: | |
| ``` | |
| cd build | |
| cmake .. | |
| cmake --build . --parallel | |
| ./vk-unittests | |
| ``` | |
| Tip: Set the [CMAKE_BUILD_PARALLEL_LEVEL](https://cmake.org/cmake/help/latest/envvar/CMAKE_BUILD_PARALLEL_LEVEL.html) environment variable to control the level of parallelism. | |
| * **Visual Studio** | |
| \ | |
| To build the Vulkan ICD library, use [Visual Studio 2019](https://visualstudio.microsoft.com/vs/community/) to open the project folder and wait for it to run CMake. Open the [CMake Targets View](https://docs.microsoft.com/en-us/cpp/build/cmake-projects-in-visual-studio?view=vs-2019#ide-integration) in the Solution Explorer and select the vk_swiftshader project to [build](https://docs.microsoft.com/en-us/cpp/build/cmake-projects-in-visual-studio?view=vs-2019#building-cmake-projects) it. | |
| Usage | |
| ----- | |
| The SwiftShader libraries act as drop-in replacements for graphics drivers. | |
| On Windows, most applications can be made to use SwiftShader's DLLs by placing them in the same folder as the executable. On Linux, the `LD_LIBRARY_PATH` environment variable or `-rpath` linker option can be used to direct applications to search for shared libraries in the indicated directory first. | |
| In general, Vulkan applications look for a shared library named `vulkan-1.dll` on Windows (`vulkan-1.so` on Linux). This 'loader' library then redirects API calls to the actual Installable Client Driver (ICD). SwiftShader's ICD is named `libvk_swiftshader.dll`, but it can be renamed to `vulkan-1.dll` to be loaded directly by the application. Alternatively, you can set the `VK_ICD_FILENAMES` environment variable to the path to `vk_swiftshader_icd.json` file that is generated under the build directory (e.g. `.\SwiftShader\build\Windows\vk_swiftshader_icd.json`). To learn more about how Vulkan loading works, read the [official documentation here](https://github.com/KhronosGroup/Vulkan-Loader/blob/master/loader/LoaderAndLayerInterface.md). | |
| Contributing | |
| ------------ | |
| See [CONTRIBUTING.txt](CONTRIBUTING.txt) for important contributing requirements. | |
| The canonical repository for SwiftShader is hosted at: | |
| https://swiftshader.googlesource.com/SwiftShader. | |
| All changes must be reviewed and approved in the [Gerrit](https://www.gerritcodereview.com/) review tool at: | |
| https://swiftshader-review.googlesource.com. You must sign in to this site with a Google Account before changes can be uploaded. | |
| Next, authenticate your account here: | |
| https://swiftshader.googlesource.com/new-password (use the same e-mail address as the one configured as the [Git commit author](https://git-scm.com/book/en/v2/Getting-Started-First-Time-Git-Setup#_your_identity)). | |
| All changes require a [Change-ID](https://gerrit-review.googlesource.com/Documentation/user-changeid.html) tag in the commit message. A [commit hook](https://git-scm.com/book/en/v2/Customizing-Git-Git-Hooks) may be used to add this tag automatically, and can be found at: | |
| https://gerrit-review.googlesource.com/tools/hooks/commit-msg. You can execute `git clone https://swiftshader.googlesource.com/SwiftShader` and manually place the commit hook in `SwiftShader/.git/hooks/`, or to clone the repository and install the commit hook in one go: | |
| git clone https://swiftshader.googlesource.com/SwiftShader && (cd SwiftShader && git submodule update --init --recursive third_party/git-hooks && ./third_party/git-hooks/install_hooks.sh) | |
| On Windows, this command line requires using the [Git Bash Shell](https://www.atlassian.com/git/tutorials/git-bash). | |
| Changes are uploaded to Gerrit by executing: | |
| git push origin HEAD:refs/for/master | |
| When ready, [add](https://gerrit-review.googlesource.com/Documentation/intro-user.html#adding-reviewers) a project [owner](OWNERS) as a reviewer on your change. | |
| Some tests will automatically be run against the change. Notably, [presubmit.sh](tests/presubmit.sh) verifies the change has been formatted using [clang-format 11.0.1](tests/kokoro/gcp_ubuntu/check_style.sh). Most IDEs come with clang-format support, but may require upgrading/downgrading to the [clang-format version 11.0.0](https://github.com/llvm/llvm-project/releases/tag/llvmorg-11.0.0) *release* version (notably Chromium's buildtools has a clang-format binary which can be an in-between revision which produces different formatting results). | |
| Testing | |
| ------- | |
| SwiftShader's Vulkan implementation can be tested using the [dEQP](https://github.com/KhronosGroup/VK-GL-CTS) test suite. | |
| See [docs/dEQP.md](docs/dEQP.md) for details. | |
| Third-Party Dependencies | |
| ------------------------ | |
| The [third_party](third_party/) directory contains projects which originated outside of SwiftShader: | |
| [subzero](third_party/subzero/) contains a fork of the [Subzero](https://chromium.googlesource.com/native_client/pnacl-subzero/) project. It originates from Google Chrome's (Portable) [Native Client](https://developer.chrome.com/native-client) project. The fork was made using [git-subtree](https://github.com/git/git/blob/master/contrib/subtree/git-subtree.txt) to include all of Subzero's history. | |
| [llvm-subzero](third_party/llvm-subzero/) contains a minimized set of LLVM dependencies of the Subzero project. | |
| [PowerVR_SDK](third_party/PowerVR_SDK/) contains a subset of the [PowerVR Graphics Native SDK](https://github.com/powervr-graphics/Native_SDK) for running several sample applications. | |
| [googletest](third_party/googletest/) contains the [Google Test](https://github.com/google/googletest) project, as a Git submodule. It is used for running unit tests for Chromium, and Reactor unit tests. Run `git submodule update --init` to obtain/update the code. Any contributions should be made upstream. | |
| Documentation | |
| ------------- | |
| See [docs/Index.md](docs/Index.md). | |
| Contact | |
| ------- | |
| Public mailing list: [swiftshader@googlegroups.com](https://groups.google.com/forum/#!forum/swiftshader) | |
| General bug tracker: https://g.co/swiftshaderbugs \ | |
| Chrome specific bugs: https://bugs.chromium.org/p/swiftshader | |
| License | |
| ------- | |
| The SwiftShader project is licensed under the Apache License Version 2.0. You can find a copy of it in [LICENSE.txt](LICENSE.txt). | |
| Files in the third_party folder are subject to their respective license. | |
| Authors and Contributors | |
| ------------------------ | |
| The legal authors for copyright purposes are listed in [AUTHORS.txt](AUTHORS.txt). | |
| [CONTRIBUTORS.txt](CONTRIBUTORS.txt) contains a list of names of individuals who have contributed to SwiftShader. If you're not on the list, but you've signed the [Google CLA](https://cla.developers.google.com/clas) and have contributed more than a formatting change, feel free to request to be added. | |
| Notes and Disclaimers | |
| --------------------- | |
| [^1]: This is not an official Google product. | |
| [^2]: Vulkan 1.3 conformance: https://www.khronos.org/conformance/adopters/conformant-products#submission_717 | |
| [^3]: Trademarks are the property of their respective owners. | |
| [^4]: OpenGL ES 3.1 conformance: https://www.khronos.org/conformance/adopters/conformant-products/opengles#submission_906 |