Struct StateTable 

pub struct StateTable<'a, T = NoPayload> {
    pub header: StateHeader<'a>,
    pub n_classes: usize,
    /* private fields */
}

Table for driving a finite state machine for layout.

The input to the state machine consists of the current state and a glyph class. The output is an entry containing the next state and a payload that is dependent on the type of layout action being performed.

See https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6Tables.html#StateHeader for more detail.

Fields

header: StateHeader<'a>

n_classes: usize

Implementations

impl<T> StateTable<'_, T>

pub const HEADER_LEN: usize

impl<T> StateTable<'_, T>

where T: FixedSize + AnyBitPattern,

pub fn class(&self, glyph_id: GlyphId16) -> Result<u8, ReadError>

Returns the class table entry for the given glyph identifier.

pub fn class_mappings(&self) -> (u16, &[u8])

Returns the first covered glyph and its consecutive class values.

pub fn entry(&self, state: u16, class: u8) -> Result<StateEntry<T>, ReadError>

Returns the entry for the given state and class.

pub fn read_value<S: Scalar>(&self, offset: usize) -> Result<S, ReadError>

Reads scalar values that are referenced from state table entries.

impl<'a, T> StateTable<'a, T>

pub fn from_parts( data: FontData<'a>, parts: &LegacyStateTableParts, ) -> Result<Self, ReadError>

Builds the state table from data and offsets previously captured with LegacyStateTableParts::read on the same data.

impl<'a> StateTable<'a, NoPayload>

pub fn read(data: FontData<'a>) -> Result<Self, ReadError>

Reads a state table whose entries carry no payload.

This exists so that StateTable::read(data) still resolves without naming the payload type: a type parameter’s default does not apply in a path expression, only in type position. Without it, adding the payload parameter would have broken every existing caller.

Remove this at the next breaking release, so that callers name the payload as they do for ExtendedStateTable.

Trait Implementations

impl<'a, T: Clone> Clone for StateTable<'a, T>

fn clone(&self) -> StateTable<'a, T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a, T> FontRead<'a> for StateTable<'a, T>

fn read_with_args(data: FontData<'a>, _: ()) -> Result<Self, ReadError>

Read an item, performing validation.

fn read(data: FontData<'a>) -> Result<Self, ReadError>

where Self: FontRead<'a, Args = ()>,

Read an instance of Self from the provided data, performing validation.

impl<T> ReadArgs for StateTable<'_, T>

type Args = ()