Struct ShapingKey 

pub struct ShapingKey {
    pub text_hash: u64,
    pub text_len: u32,
    pub script: Script,
    pub direction: RunDirection,
    pub style_id: u64,
    pub font_id: FontId,
    pub size_256ths: u32,
    pub features: FontFeatures,
    pub generation: u64,
}

Deterministic cache key for shaped glyph output.

Captures all parameters that affect shaping results. Two identical keys are guaranteed to produce identical ShapedRun output, enabling safe caching.

Key components

Field	Purpose
text_hash	FxHash of the text content
text_len	Byte length (collision avoidance)
script	Unicode script (affects glyph selection)
direction	LTR/RTL (affects reordering + positioning)
style_id	Style discriminant (bold/italic affect glyphs)
font_id	Font face identity
size_256ths	Font size in 1/256th point units
features	Active OpenType features
generation	Cache generation (invalidation epoch)

Fields

text_hash: u64

FxHash of the text content.

text_len: u32

Byte length of the text (for collision avoidance with the hash).

script: Script

Unicode script.

direction: RunDirection

Text direction.

style_id: u64

Style discriminant.

font_id: FontId

Font face identity.

size_256ths: u32

Font size in 1/256th of a point (sub-pixel precision matching ftui-render).

features: FontFeatures

Active OpenType features (canonicalized for determinism).

generation: u64

Cache generation epoch — entries from older generations are stale.

Implementations

impl ShapingKey

pub fn new( text: &str, script: Script, direction: RunDirection, style_id: u64, font_id: FontId, size_256ths: u32, features: &FontFeatures, generation: u64, ) -> Self

Build a key from shaping parameters.

Trait Implementations

impl Clone for ShapingKey

fn clone(&self) -> ShapingKey

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ShapingKey

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

Formats the value using the given formatter.

impl Hash for ShapingKey

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ShapingKey

fn eq(&self, other: &ShapingKey) -> 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 Eq for ShapingKey

impl StructuralPartialEq for ShapingKey