Struct FontData 

pub struct FontData<'a> {
    bytes: &'a [u8],
}

A reference to raw binary font data.

This is a wrapper around a byte slice, that provides convenience methods for parsing and validating that data.

Fields

bytes: &'a [u8]

Implementations

impl FontData<'static>

const NULL_POOL_SIZE: usize = 262

The number of bytes required to represent the largest table we have.

This is checked by an assert at compile time, and can be increased as needed.

pub(crate) fn default_table_data() -> Self

Return all zeroes suitable for the default impl of a table.

pub(crate) fn default_format_1_u16_table_data() -> Self

Return a [0x0, 0x01] byte pair (u16be) and then all zeros, to represent the default impl of a format 1 table with u16 format.

pub(crate) fn default_format_1_u8_table_data() -> Self

Return a single 0x01 and then all zeros, to represent the default impl of a format 1 table with u8 format.

pub(crate) const fn default_data_long_enough(n_bytes: usize) -> bool

Return true if our default data can represent a table n_bytes long

impl<'a> FontData<'a>

pub const EMPTY: FontData<'static>

Empty data, useful for some tests and examples

pub const fn new(bytes: &'a [u8]) -> Self

Create a new FontData with these bytes.

You generally don’t need to do this? It is handled for you when loading data from disk, but may be useful in tests.

pub fn len(&self) -> usize

The length of the data, in bytes

pub fn is_empty(&self) -> bool

true if the data has a length of zero bytes.

pub fn split_off(&self, pos: usize) -> Option<FontData<'a>>

Returns self[pos..]

pub fn take_up_to(&mut self, pos: usize) -> Option<FontData<'a>>

returns self[..pos], and updates self to = self[pos..];

pub fn slice(&self, range: impl RangeBounds<usize>) -> Option<FontData<'a>>

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

Read a scalar at the provided location in the data.

pub fn read_be_at<T: Scalar>( &self, offset: usize, ) -> Result<BigEndian<T>, ReadError>

Read a big-endian value at the provided location in the data.

pub fn read_with_args<T>( &self, range: Range<usize>, args: &T::Args, ) -> Result<T, ReadError>

where T: FontReadWithArgs<'a>,

fn check_in_bounds(&self, offset: usize) -> Result<(), ReadError>

pub fn read_ref_at<T: AnyBitPattern + FixedSize>( &self, offset: usize, ) -> Result<&'a T, ReadError>

Interpret the bytes at the provided offset as a reference to T.

Returns an error if the slice offset.. is shorter than T::RAW_BYTE_LEN.

This is a wrapper around read_ref_unchecked, which panics if the type does not uphold the required invariants.

Panics

This function will panic if T is zero-sized, has an alignment other than one, or has any internal padding.

pub fn read_array<T: AnyBitPattern + FixedSize>( &self, range: Range<usize>, ) -> Result<&'a [T], ReadError>

Interpret the bytes at the provided offset as a slice of T.

Returns an error if range is out of bounds for the underlying data, or if the length of the range is not a multiple of T::RAW_BYTE_LEN.

This is a wrapper around read_array_unchecked, which panics if the type does not uphold the required invariants.

Panics

This function will panic if T is zero-sized, has an alignment other than one, or has any internal padding.

pub(crate) fn cursor(&self) -> Cursor<'a>

pub fn as_bytes(&self) -> &'a [u8]

Return the data as a byte slice

Trait Implementations

impl AsRef<[u8]> for FontData<'_>

fn as_ref(&self) -> &[u8]

Converts this type into a shared reference of the (usually inferred) input type.

impl<'a> Clone for FontData<'a>

fn clone(&self) -> FontData<'a>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Debug for FontData<'a>

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

Formats the value using the given formatter.

impl<'a> Default for FontData<'a>

fn default() -> FontData<'a>

Returns the “default value” for a type.

impl<'a> FontRead<'a> for FontData<'a>

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

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

impl<'a> From<&'a [u8]> for FontData<'a>

fn from(src: &'a [u8]) -> FontData<'a>

Converts to this type from the input type.

impl<'a> From<FontData<'a>> for Cow<'a, [u8]>

Available on crate feature std only.

fn from(src: FontData<'a>) -> Self

Converts to this type from the input type.

impl<'a> Copy for FontData<'a>