Enum AntiAlias 

pub enum AntiAlias {
    On,
    Off,
    FullCover,
}

Whether a primitive’s edges are antialiased.

The three modes are AGG’s three, and they are genuinely three rather than a flag and its negation:

• On integrates coverage and writes it as alpha.
• Off is the oracle’s aliased_path, which thresholds the same coverage at > 127 -> 255 rather than turning the rasterizer off. It is what the axis-aligned rect fast path and a hard-edged clip ask for.
• FullCover keeps the rasterizer’s choice of which pixels a span covers and then ignores the coverage value, writing every one of them at the source alpha.

The distinction between the last two is the whole reason FullCover exists. Thresholding drops a pixel two abutting cells each cover halfway, so a subdivided Coons patch shows white pin-holes along every internal seam; full_cover paints it from both cells, which is what makes the patch continuous.

Variants

On

Antialiased, the default for every ordinary fill and stroke.

Off

Hard-edged: coverage thresholded at its midpoint.

FullCover

Every touched pixel at full alpha, whatever its coverage.

Trait Implementations

impl Clone for AntiAlias

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 AntiAlias

impl Debug for AntiAlias

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

Formats the value using the given formatter.

impl Default for AntiAlias

fn default() -> Self

Returns the “default value” for a type.

impl Eq for AntiAlias

impl PartialEq for AntiAlias

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for AntiAlias