Struct BitmapFont

pub struct BitmapFont<'glyphs, T> {
    pub glyphs: &'glyphs [T],
    pub first_glyph: char,
    pub extra_glyphs: &'glyphs [(char, T)],
    pub width: u8,
    pub height: u8,
    pub baseline: u8,
    pub advance_x: u8,
    pub advance_y: u8,
}

Available on crate feature font only.

A simple bitmap font for rendering fixed-size glyphs.

Each glyph is stored as a bitfield in a generic type and is assumed to have fixed dimensions (width × height), a baseline, and an advance metric.

The glyphs are arranged sequentially starting from first_glyph.

The font supports drawing text into both mono and RGBA buffers, as well as using a custom per-pixel color function.

Fields

glyphs: &'glyphs [T]

A slice of glyphs.

first_glyph: char

The first char in glyphs.

extra_glyphs: &'glyphs [(char, T)]

A slice of extra paired glyphs.

width: u8

The width of each glyph in pixels.

height: u8

The height of each glyph in pixels.

baseline: u8

Where the base line sits in the height.

advance_x: u8

Horizontal space to advance after each glyph.

advance_y: u8

Vertical space to advance after each new line.

Implementations

impl<T: Copy + Into<u64>> BitmapFont<'_, T>

pub fn text_width(&self, text: &str) -> usize

Returns the rendered text width.

pub const fn height(&self) -> u8

Returns the height of any glyph.

pub const fn width(&self) -> u8

Returns the width of any glyph.

pub fn draw_mono( &self, buffer: &mut [u8], width: usize, x: isize, y: isize, text: &str, )

Draws grayscale text into a one-byte-per-pixel buffer.

pub fn draw_rgba( &self, buffer: &mut [u8], width: usize, x: isize, y: isize, text: &str, color: [u8; 4], )

Draws RGBA text into a 4-bytes-per-pixel buffer.

pub fn draw_rgba_with<F>( &self, buffer: &mut [u8], width: usize, x: isize, y: isize, text: &str, color_fn: F, )

where F: FnMut(usize, usize, usize) -> [u8; 4],

Draws RGBA text with a custom color function.

The provided closure is called for each “on” pixel and receives the glyph‑local x and y coordinates (i.e. within the glyph) and the index of the current character. It should return a [u8; 4] color (RGBA) for that pixel.

Trait Implementations

impl<'glyphs, T: Clone> Clone for BitmapFont<'glyphs, T>

fn clone(&self) -> BitmapFont<'glyphs, T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T> Debug for BitmapFont<'_, T>

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

Formats the value using the given formatter.

impl<'glyphs, T: Hash> Hash for BitmapFont<'glyphs, T>

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<'glyphs, T: PartialEq> PartialEq for BitmapFont<'glyphs, T>

fn eq(&self, other: &BitmapFont<'glyphs, T>) -> 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<'glyphs, T: Eq> Eq for BitmapFont<'glyphs, T>

impl<'glyphs, T> StructuralPartialEq for BitmapFont<'glyphs, T>