Enum BackbufferMode 

pub enum BackbufferMode {
    Rgba,
    LcdCoverage,
}

How a widget’s backbuffer stores pixels.

The choice controls what the framework allocates as the render target during paint_subtree_backbuffered and how the cached bitmap is composited back onto the parent.

Variants

Rgba

8-bit straight-alpha RGBA. Standard Porter-Duff SRC_ALPHA, ONE_MINUS_SRC_ALPHA composite on blit. Works for any widget, including ones with transparent areas. Text inside is grayscale AA (no LCD subpixel).

LcdCoverage

3 bytes-per-pixel composited opaque RGB — no alpha channel. Every fill (rects, strokes, text, etc.) inside the buffer goes through the 3× horizontal supersample + 5-tap filter + per-channel src-over pipeline described in lcd-subpixel-compositing.md. The buffer is blitted as an opaque RGB texture.

Contract: the widget is responsible for painting content that covers its full bounds with opaque fills (starting with a bg rect). Uncovered pixels land as black on the parent because there is no alpha channel to carry “no paint here.”

Trait Implementations

impl Clone for BackbufferMode

fn clone(&self) -> BackbufferMode

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for BackbufferMode

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

Formats the value using the given formatter.

impl PartialEq for BackbufferMode

fn eq(&self, other: &BackbufferMode) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for BackbufferMode

impl Eq for BackbufferMode

impl StructuralPartialEq for BackbufferMode