Bevy FrameBuffer

Bevy framebuffer rendering using pixels or softbuffer.

Functionality

bevy framebuffer rendering with the choice of either a pixels or softbuffer pixel buffer backend. Just specify the backend as a feature, and access it with NonSend or NonSendMut.

// Add either the plugins below, or `DefaultPlugins`.
app.add_plugins((
    MinimalPlugins,
    WindowPlugin::default(),
    AccessibilityPlugin,
    WinitPlugin::<WakeUp>::default(),
));
// Configure `FrameBufferPlugin` with either `PixelsConfig` or `SoftBufferConfig`,
// depending on the enabled feature.
app.add_plugins(FrameBufferPlugin {
    config: PixelsConfig {
        width: 320,
        height: 180,
        ..Default::default()
    },
})
// Add a render system.
.add_systems(RenderSchedule, render_system);

// Access the framebuffer in systems with `NonSend` or `NonSendMut`.
pub fn render_system(buffer: NonSendMut<PixelsFrame>) {
    buffer.render().unwrap();
}

This crate, by design, only adds FrameBuffer<T> as a resource and avoids adding systems (including a render system) beyond that. This choice was made to leave allow the user a degree of flexibility in how rendering and window events are handled by the user, especially in relation to the divergent default behaviour of pixels and softbuffer. See [examples] for how one might implement basic functionality.

Backends

This crate offers pixels and softbuffer as a framebuffer backend. Note that the functionality of backends varies, and it is recommended to become familiar with your backend of choice. bevy_framebuffer requires exactly one of the following features to be enabled:

Schedules

Two schedules are provided by bevy_framebuffer, SurfaceSchedule and RenderSchedule. Resizing/scaling operations should be run on the SurfaceSchedule, which runs after PreUpdate. Rendering should be run on the RenderSchedule which runs before Last. These schedules are included with the default schedule feature, which can be disabled if needed.

Examples

Minimal examples are provided for both softbuffer and pixels, showing how one might approach scaling and rendering for the given backend.

# Run the `pixels` example.
cargo run --example minimal_pixels --features="pixels"
# Run the `softbuffer` example.
cargo run --example minimal_softbuffer --features="softbuffer"

Safety

This crate uses unsafe to expose raw_window_handler implementations with the caveat that certain platforms do not support usage off of the main thread. As such, bevy_framebuffer enforces main thread access on all platforms, enforcing FrameBuffer as a NonSend/NonSendMut resource.

Bevy compatability

License: MIT OR Apache-2.0