Cross-platform Real-Time Rendering Library

`Linux/Mac CPU`	`Windows CPU`

Status: currently bringing up the foundations of the library and massaging code from previous internal projects to something acceptable for public release. Please be patient!

A lightweight framework for writing efficient cross-platform rendering code in modern C++. It abstracts operating system and toolchain concepts to enable quick prototyping and interation of rich interactive applications that run beautifully everywhere. The library is engineered for small code sizes to enable fast loading and low resource usage even within web browsers.

Pronounced ‘zurtle’.

This is not an official Google product.

Setup Instructions

MacOS

Install clang (and clang-tools-extra) from the LLVM downloads page
Install bazel via homebrew or the bazel releases page:
```
$ brew install bazel go
```
Install protobuf:
```
$ sudo easy_install protobuf
```
Run initial setup with xtool:
```
$ ./xtool setup
```

Ubuntu

Install clang (and clang-tools-extra) from the LLVM downloads page

Install bazel via your package manager or the bazel releases page:

$ sudo apt-get install bazel golang-go libegl1-mesa-dev libgles2-mesa-dev

Run initial setup with xtool:
```
$ ./xtool setup
```

Windows

Install clang (and clang-tools-extra) from the LLVM downloads page
Install Visual Studio 2017 with the Windows SDK and C++ tools
Install bazel via chocolatey or the bazel releases page:
```
> choco install bazel golang
```
Follow the bazel on Windows instructions (set BAZEL_SH, etc)
Run initial setup with xtool:
```
> xtool setup
```

IDE Setup

Visual Studio 2017

Generate a Visual Studio solution; do this each time you change BUILD files:
```
> xtool sln
```
Open .vs\xrtl.sln, select a project, and press F5!

CLion

Install the ‘CLion with Bazel’ plugin from the repository.
Import the bazel project from the root git folder.
Set the bazel binary to xtool (or xtool.bat on Windows).
Import the project view from the workspace .bazelproject file.

If clang is not your default CC you should start CLion with CC=clang.

Developing

Build/test/run/query for host platform:

$ ./xtool build --all
$ ./xtool test --all
$ ./xtool run //xrtl/base:math_test_linux -- --some_arg
# Note that you can use `bazel` instead of `xtool` in most cases, but you must
# specify a config.
$ bazel build --config=macos_x86_64 //xrtl/base/...

Run linter and fix common errors:
```
$ ./xtool fix
```

Debugging Notes

GDB may need the following commands run at startup to resolve some third party source code. Replace directories with your workspace location:

dir $HOME/xrtl/bazel-xrtl
set substitute-path external/com_github_google_swiftshader $HOME/xrtl/third_party/swiftshader/
set substitute-path external/com_github_khronosgroup_glslang $HOME/xrtl/third_party/glslang/

Committing Code

Run presubmit to perform lint/style check/run tests.
```
$ ./xtool presubmit --fix
```

Testing

Test Tags

Common tags that can be added to tests:

exclusive: no other tests should run while this test is executing.
requires_gui: test uses a GUI and requires a window manager (X11/etc).
requires_gpu: test requires a real hardware GPU to run.

# Run all tests except those that require a hardware GPU:
$ ./xtool test --all --test_tag_filter=-requires_gpu