Struct Font

pub struct Font {
    pub(crate) handle: PlatformFont,
    pub(crate) template: FontTemplateRef,
    pub metrics: FontMetrics,
    pub descriptor: FontDescriptor,
    data_and_index: OnceLock<FontDataAndIndex>,
    shaper: OnceLock<Shaper>,
    cached_shape_data: RwLock<CachedShapeData>,
    pub(crate) font_instance_key: OnceLock<FontInstanceKey>,
    pub(crate) synthesized_small_caps: Option<FontRef>,
    has_color_bitmap_or_colr_table: OnceLock<bool>,
    can_do_fast_shaping: OnceLock<bool>,
}

Fields

handle: PlatformFont

template: FontTemplateRef

metrics: FontMetrics

descriptor: FontDescriptor

data_and_index: OnceLock<FontDataAndIndex>

The data for this font. And the index of the font within the data (in case it’s a TTC) This might be uninitialized for system fonts.

shaper: OnceLock<Shaper>

cached_shape_data: RwLock<CachedShapeData>

font_instance_key: OnceLock<FontInstanceKey>

synthesized_small_caps: Option<FontRef>

If this is a synthesized small caps font, then this font reference is for the version of the font used to replace lowercase ASCII letters. It’s up to the consumer of this font to properly use this reference.

has_color_bitmap_or_colr_table: OnceLock<bool>

Whether or not this font supports color bitmaps or a COLR table. This is essentially equivalent to whether or not we use it for emoji presentation. This is cached, because getting table data is expensive.

can_do_fast_shaping: OnceLock<bool>

Whether or not this font can do fast shaping, ie whether or not it has a kern table, but no GSUB and GPOS tables. When this is true, Servo will shape Latin horizontal left-to-right text without using Harfbuzz.

FIXME: This should be removed entirely in favor of better caching if necessary. See https://github.com/servo/servo/pull/11273#issuecomment-222332873.

Implementations

impl Font

pub fn new( template: FontTemplateRef, descriptor: FontDescriptor, data: Option<FontData>, synthesized_small_caps: Option<FontRef>, ) -> Result<Font, &'static str>

pub fn identifier(&self) -> FontIdentifier

A unique identifier for the font, allowing comparison.

pub(crate) fn webrender_font_instance_flags(&self) -> FontInstanceFlags

pub(crate) fn has_color_bitmap_or_colr_table(&self) -> bool

pub fn key(&self, font_context: &FontContext) -> FontInstanceKey

pub fn font_data_and_index(&self) -> Result<&FontDataAndIndex, FontDataError>

Return the data for this Font. Note that this is currently highly inefficient for system fonts and should not be used except in legacy canvas code.

pub(crate) fn variations(&self) -> &[FontVariation]

impl Font

pub fn shape_text( &self, text: &str, options: &ShapingOptions, ) -> Arc<GlyphStore>

fn shape_text_harfbuzz( &self, text: &str, options: &ShapingOptions, glyphs: &mut GlyphStore, )

pub fn can_do_fast_shaping(&self, text: &str, options: &ShapingOptions) -> bool

Whether not a particular text and ShapingOptions combination can use “fast shaping” ie shaping without Harfbuzz.

Note: This will eventually be removed.

fn shape_text_fast( &self, text: &str, options: &ShapingOptions, glyphs: &mut GlyphStore, )

Fast path for ASCII text that only needs simple horizontal LTR kerning.

pub(crate) fn table_for_tag(&self, tag: Tag) -> Option<FontTable>

pub fn glyph_index(&self, codepoint: char) -> Option<u32>

pub(crate) fn has_glyph_for(&self, codepoint: char) -> bool

pub(crate) fn glyph_h_kerning(&self, first_glyph: u32, second_glyph: u32) -> f64

pub fn glyph_h_advance(&self, glyph_id: u32) -> f64

pub fn typographic_bounds(&self, glyph_id: u32) -> Rect<f32>

pub fn baseline(&self) -> Option<FontBaseline>

Get the FontBaseline for this font.

Trait Implementations

impl MallocSizeOf for Font

fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize

Measure the heap usage of all descendant heap-allocated structures, but not the space taken up by the value itself.