Audio engine

Adds an audio engine abstraction (implemented with miniaudio) in Rive. We can selectively replace it with other abstractions later if we find miniaudio isn't well suited everywhere but I'm confident it will be based on flexibility with getting it working in the recorder.

Adds audio support in:

- packages/rive_common
  - WASM: rive_audio_wasm.dart
  - FFI: rive_audio_ffi.dart
- packages/runtime
- packages/recorder

Subsequent PR will add support in:

- packages/rive_unity
  - This is getting meaty enough...
- packages/rive_flutter
  - This requires publishing rive_common so I want to make sure this is reviewed and accepted before publishing
  - I'd also prefer to merge layout constraints into rive_common before this lands.

Editor features:
- Updated preview window:
<img width="248" alt="CleanShot 2024-01-15 at 14 44 31@2x" src="">

- Preview waveforms in the timeline:
<img width="651" alt="CleanShot 2024-01-15 at 14 44 53@2x" src="">

- Subsequent PR will also use threads in web editor build (currently uses a time/frame based decoder to offload ui). I can't do that until I can verify the Shared Memory access is granted once rive_common lands in and then we can push to UAT.

73bf11db3 Audio engine (#6454)

Co-authored-by: Luigi Rosso <>
52 files changed
tree: 2a5c0a62d8ea5d5cca0b8398dc81b66c371ddb03
  1. .github/
  2. .vscode/
  3. build/
  4. cg_renderer/
  5. decoders/
  6. dependencies/
  7. dev/
  8. include/
  9. rivinfo/
  10. skia/
  11. src/
  12. tess/
  13. test/
  14. utils/
  15. viewer/
  16. .dockerignore
  17. .gitignore
  18. .lua-format
  19. .rive_head
  21. Dockerfile
  22. Doxyfile

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Rive hero image

Rive C++ is a runtime library for Rive, a real-time interactive design and animation tool.

The C++ runtime for Rive provides these runtime features:

  • Loading Artboards and their contents from .riv files.
  • Querying LinearAnimations and StateMachines from Artboards.
  • Making changes to Artboard hierarchy (fundamentally same guts used by LinearAnimations and StateMachines) and effienclty solving those changes via Artboard::advance.
  • Abstract Renderer for submitting high level vector path commands with retained path objects to optimize and minimize path re-computation (ultimately up to the concrete rendering implementation).
  • Example concrete renderer written in C++ with Skia. Skia renderer code is in skia/renderer/src/skia_factory.cpp.

Build System

We use premake5. The Rive dev team primarily works on MacOS. There is some work done by the community to also support Windows and Linux. PRs welcomed for specific platforms you wish to support! We encourage you to use premake as it's highly extensible and configurable for a variety of platforms.


In the rive-cpp directory, run to debug build and release for a release build.

If you've put the premake5 executable in the rive-cpp/build folder, you can run it with PATH=.:$PATH ./

Rive makes use of clang vector builtins, which are, as of 2022, still a work in progress. Please use clang and ensure you have the latest version.

Building skia projects

cd skia/dependencies
./      // this will invoke

To build viewer (plus you'll needed CMake installed)



Uses the Catch2 testing framework.

cd dev

In the dev directory, run to compile and execute the tests.

(if you've installed premake5 in rive-cpp/build, you can run it with PATH=../../build:$PATH ./

The tests live in rive/test. To add new tests, create a new xxx_test.cpp file here. The test harness will automatically pick up the new file.

There's a VSCode command provided to run tests from the Tasks: Run Task command palette.

Code Formatting

rive-cpp uses clang-format, you can install it with brew on MacOS: brew install clang-format.

Memory Checks

Note that if you‘re on MacOS you’ll want to install valgrind, which is somewhat complicated these days. This is the easiest solution (please PR a better one when it becomes available).

brew tap LouisBrunner/valgrind
brew install --HEAD LouisBrunner/valgrind/valgrind

You can now run the all the tests through valgrind by running memory.

Disassembly Explorer

If you want to examine the generated assembly code per cpp file, install Disassembly Explorer in VSCode.

A disassemble task is provided to compile and preview the generated assembly. You can reach it via the Tasks: Run Task command palette or you can bind it to a shortcut by editing your VSCode keybindings.json:

        "key": "cmd+d",
        "command": "workbench.action.tasks.runTask",
        "args": "disassemble"