Enum Engine 

pub enum Engine {
    Interpreter,
    Auto(Option<GlyphStyles>),
    AutoFallback,
}

Specifies the backend to use when applying hints.

Variants

Interpreter

The TrueType or PostScript interpreter.

Auto(Option<GlyphStyles>)

The automatic hinter that performs just-in-time adjustment of outlines.

Glyph styles can be precomputed per font and may be provided here as an optimization to avoid recomputing them for each instance.

AutoFallback

Selects the engine based on the same rules that FreeType uses when neither of the FT_LOAD_NO_AUTOHINT or FT_LOAD_FORCE_AUTOHINT load flags are specified.

Specifically, PostScript (CFF/CFF2) fonts will always use the hinting engine in the PostScript interpreter and TrueType fonts will use the interpreter for TrueType instructions if one of the fpgm or prep tables is non-empty, falling back to the automatic hinter otherwise.

This uses OutlineGlyphCollection::prefer_interpreter to make a selection.

Implementations

impl Engine

fn resolve_auto_fallback(self, outlines: &OutlineGlyphCollection<'_>) -> Engine

Converts the AutoFallback variant into either Interpreter or Auto based on the given outline set’s preference for interpreter mode.

Trait Implementations

impl Clone for Engine

fn clone(&self) -> Engine

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Engine

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

Formats the value using the given formatter.

impl Default for Engine

fn default() -> Engine

Returns the “default value” for a type.

impl From<Engine> for HintingOptions

fn from(value: Engine) -> Self

Converts to this type from the input type.