Struct FbdevSurface 

pub struct FbdevSurface { /* private fields */ }

A framebuffer, drawn into through a shadow buffer.

Why a shadow buffer

The mapped framebuffer is being scanned out continuously; there is nothing to flip to. Rendering into it directly would put every intermediate state on screen — the clear before the redraw above all — which reads as flicker on exactly the panels this backend exists for. So drawing goes to memory we own and present copies out only the damaged rows.

That also makes the buffer age honest: the shadow persists frame to frame, so it is BufferAge::Frames(1) and incremental repaint works exactly as it does on DRM.

What this cannot do

There is no page flip and no vsync. A copy that lands mid-scanout will tear, and nothing here can prevent it — FBIO_WAITFORVSYNC is optional and widely unimplemented. Keeping damage small keeps the tear small, which is the only mitigation fbdev offers.

Implementations

impl FbdevSurface

pub fn open(path: impl AsRef<Path>) -> Result<Self, FbdevError>

Opens a specific node, such as /dev/fb0.

pub fn open_first() -> Result<Self, FbdevError>

Opens the first framebuffer node that can be read and understood.

pub fn info(&self) -> FbInfo

The geometry in force.

pub fn path(&self) -> &Path

The node this surface was opened from.

Trait Implementations

impl Debug for FbdevSurface

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Surface for FbdevSurface

fn size(&self) -> Size

Visible extent in physical pixels.

fn scale_factor(&self) -> f32

Physical pixels per logical pixel. 1.0 on a typical panel.

fn format(&self) -> PixelFormat

Word layout the backend will scan out.

fn acquire(&mut self) -> Result<Frame<'_>, SurfaceError>

Takes the next drawable buffer.

fn present(&mut self, damage: &[Rect]) -> Result<(), SurfaceError>

Publishes the frame, telling the backend which regions changed.