Struct zng::font::FontFaceMetrics

pub struct FontFaceMetrics {
    pub units_per_em: u32,
    pub ascent: f32,
    pub descent: f32,
    pub line_gap: f32,
    pub underline_position: f32,
    pub underline_thickness: f32,
    pub cap_height: f32,
    pub x_height: f32,
    pub bounds: Rect<f32, ()>,
}

Various metrics that apply to the entire FontFace.

For OpenType fonts, these mostly come from the OS/2 table.

See the FreeType Glyph Metrics documentation for an explanation of the various metrics.

Fields

units_per_em: u32

The number of font units per em.

Font sizes are usually expressed in pixels per em; e.g. 12px means 12 pixels per em.

ascent: f32

The maximum amount the font rises above the baseline, in font units.

descent: f32

The maximum amount the font descends below the baseline, in font units.

This is typically a negative value to match the definition of sTypoDescender in the OS/2 table in the OpenType specification. If you are used to using Windows or Mac APIs, beware, as the sign is reversed from what those APIs return.

line_gap: f32

Distance between baselines, in font units.

underline_position: f32

The suggested distance of the top of the underline from the baseline (negative values indicate below baseline), in font units.

underline_thickness: f32

A suggested value for the underline thickness, in font units.

cap_height: f32

The approximate amount that uppercase letters rise above the baseline, in font units.

x_height: f32

The approximate amount that non-ascending lowercase letters rise above the baseline, in font units.

bounds: Rect<f32, ()>

A rectangle that surrounds all bounding boxes of all glyphs, in font units.

This corresponds to the xMin/xMax/yMin/yMax values in the OpenType head table.

Implementations

impl FontFaceMetrics

pub fn sized(&self, font_size_px: Px) -> FontMetrics

Compute FontMetrics given a font size in pixels.

Trait Implementations

impl Clone for FontFaceMetrics

fn clone(&self) -> FontFaceMetrics

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for FontFaceMetrics

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for FontFaceMetrics

fn deserialize<__D>( __deserializer: __D, ) -> Result<FontFaceMetrics, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<'a> From<Face<'a>> for FontFaceMetrics

fn from(f: Face<'a>) -> FontFaceMetrics

Converts to this type from the input type.

impl Serialize for FontFaceMetrics

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.