Struct MaskSpans 

pub struct MaskSpans { /* private fields */ }

Inline collection of mask spans for one row.

Most mask shapes produce ≤ 5 spans per row (e.g., rounded rect: transparent, partial, opaque, partial, transparent). The inline capacity of 8 covers all practical cases without allocation.

Implementations

impl MaskSpans

pub fn new() -> MaskSpans

Create an empty span list.

pub fn uniform(width: u32, kind: SpanKind) -> MaskSpans

Create a span list with a single span covering the full width.

pub fn push(&mut self, span: MaskSpan)

Add a span. Panics if capacity (8) is exceeded.

pub fn len(&self) -> usize

Number of spans.

pub fn is_empty(&self) -> bool

Whether there are no spans.

pub fn iter(&self) -> impl Iterator<Item = &MaskSpan>

Iterate over spans.

pub fn to_mask_fill(&self) -> MaskFill

Convert to the legacy MaskFill hint (for callers that don’t use spans).

pub fn align_to(&mut self, align: u32)

Snap span boundaries to pixel multiples of align, expanding Partial spans and shrinking Opaque/Transparent neighbors.

align is in pixels (e.g., 2 for AVX2 4ch RGBA, 4 for AVX-512 4ch). After alignment, every Partial span’s start and end are multiples of align (clamped to [0, width]), so the SIMD kernel processes clean blocks with no scalar tail.

This is always safe because:

• Expanding Partial into Opaque territory: mask=1.0, multiply is identity.
• Expanding Partial into Transparent territory: mask=0.0, multiply zeros.

Spans that shrink to zero width are removed. Adjacent spans with the same kind after adjustment are merged.

Trait Implementations

impl Clone for MaskSpans

fn clone(&self) -> MaskSpans

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MaskSpans

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

Formats the value using the given formatter.

impl Default for MaskSpans

fn default() -> MaskSpans

Returns the “default value” for a type.