Enum LayerFilter 

pub enum LayerFilter {
    Blur {
        sigma: f32,
    },
    DropShadow {
        offset: (f32, f32),
        sigma: f32,
        color: AlphaColor<Srgb>,
    },
}

A filter the engine can apply to an isolated layer.

Engine-internal on purpose: this is the vocabulary push_filter_layer records with, not a frust_scene command.

Variants

Blur

A Gaussian blur of standard deviation sigma, in the layer’s own user space — the transform in force when the layer is opened scales it into device space.

Fields

sigma: f32

The blur’s standard deviation. Zero blurs nothing.

DropShadow

A shadow-only drop shadow: the layer’s alpha, blurred by sigma, shifted by offset, and recoloured to color — never the layer’s own unfiltered content composited back over it (see drop_shadow’s own doc for why).

Fields

offset: (f32, f32)

Horizontal, vertical offset of the shadow, in the layer’s own user space — the transform in force when the layer is opened scales it into device space, exactly as sigma is.

sigma: f32

The shadow’s blur standard deviation. Zero blurs nothing, leaving a hard-edged, offset silhouette.

color: AlphaColor<Srgb>

The shadow’s own colour. Its alpha scales the shadow’s own opacity; the layer’s colour never reaches the shadow.

Implementations

impl LayerFilter

pub fn filter_data(self, transform: Affine) -> Result<FilterData, EngineError>

The recorder-side description of this filter under transform.

This is what carries the filter’s expansion into the recording: a blurred layer’s tile-aligned bounds grow by 3σ on every side, because the blur paints outside the contents that produced it, and the page the layer is rendered into is sized from those grown bounds.

Errors

EngineError::InvalidGeometry for a σ that is not finite, is negative, or is past MAX_BLUR_SIGMA — in the layer’s own user space or in the device space transform scales it into (a Self::DropShadow’s own offset held to the same finiteness) — and EngineError::InvalidTransform for a transform that is not finite — the same terms the compiler already refuses a draw’s own geometry and transform on, checked here because every quantity below is derived from both.

Trait Implementations

impl Clone for LayerFilter

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for LayerFilter

impl Debug for LayerFilter

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

Formats the value using the given formatter.

impl PartialEq for LayerFilter

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for LayerFilter