Project Layout

Project Layout

• core: Core emulator code, shared among all platforms
• swf: Crate to handle SWF and AS parsing
• desktop: Desktop frontend and backend code
• web: Web frontend and backend code
  • demo: The web demo page (served at https://ruffle.rs/demo)

Core

The core directory contains the Flash Player emulation code. This is used on all platforms to parse and execute the SWF file. The Player struct is the main entry point of the core code.

SWF

The swf directory contains a library for reading and writing SWF files and ActionScript bytecode.

Backends

There are several different types of backends to handle platform-specific behavior. There is a trait defining the interface for each type of backend. In addition, a "null" backend is provided for "no-op" behavior during development (for example, NullAudioBackend does not play any audio).

An instance of each backend type is passed into Player when it is created. Player uses trait objects to reference the backends, allowing for the backends to be dynamically chosen at runtime.

Rendering backend

The rendering backend handles drawing vector art, bitmaps, and text in whatever way suits the platform. The interface is defined by the RenderBackend trait.

Current rendering backends:

• NullRenderBackend
• GliumRenderBackend (desktop, using lyon for vector art tessellation and glium for rendering)
• CanvasRenderBackend (web, using HTML5 CanvasRenderingContext2d)

Potential future changes:

• Desktop
  • Drop glium in favor of gfx-hal
  • Add Pathfinder backend
  • Add software rendering backend?
• Web
  • Use gfx-hal and WebGL over canvas by default

Audio backend

The audio backend controls the playback, mixing, and dynamic control of audio from the SWF file. The interface is defined by the AudioBackend trait.

Current audio backends:

• NullAudioBackend
• RodioAudioBackend (desktop, using rodio)
• WebAudioBackend (web, using Web Audio API).

Potential future changes:

• Desktop
  • Drop rodio and use only cpal, doing all the mixing ourselves.
• Web
  • Decode audio on the fly and playback using ScriptProcessorNode. (possibly as an option).
  • Use AudioWorklet as they become standardized.

UI Backend

Not yet implemented. This backend will handle things such as changing mouse pointer state.

Navigator Backend

Not yet implemented. This backend will handle things such as loading external content, HTTP calls, or browsing to different pages.