Struct Font 

pub struct Font {
    pub units_per_em: u16,
    pub num_glyphs: u16,
    pub ascent: i16,
    pub descent: i16,
    pub line_gap: i16,
    /* private fields */
}

A parsed font, owning its backing bytes.

Fields

units_per_em: u16

Font design units per em (the coordinate scale; advances are in these).

num_glyphs: u16

Number of glyphs in the font.

ascent: i16

Typographic ascender (design units).

descent: i16

Typographic descender (design units, usually negative).

line_gap: i16

Recommended extra line gap (design units).

Implementations

impl Font

pub fn glyph_outline(&self, gid: u16) -> Result<GlyphOutline, OutlineError>

Decode glyph gid to quadratic contours with phantom-point-correct metrics. Blank glyphs (space) succeed with empty contours.

Errors

OutlineError::NoGlyfOutlines for CFF-only fonts, OutlineError::BadGlyphId for out-of-range ids, and OutlineError::Malformed / OutlineError::BudgetExceeded for structurally invalid or hostile glyph data.

impl Font

pub fn parse(data: Vec<u8>) -> Result<Self, FontError>

Parse a font from its raw bytes (e.g. an include_bytes! blob).

Errors

Returns a FontError for a non-sfnt file, a missing required table, a truncated file, or the absence of a usable Unicode cmap.

pub fn has_glyf_outlines(&self) -> bool

True when the font carries TrueType (glyf) outlines we can read/subset.

pub fn glyph_data(&self, gid: u16) -> Option<&[u8]>

Raw glyf bytes for glyph gid (for subset embedding), or None. An empty (zero-length) glyph yields Some(&[]).

pub fn glyph_bbox(&self, gid: u16) -> Option<[i16; 4]>

Glyph bounding box [xMin, yMin, xMax, yMax] (design units), or None for an empty glyph / no outlines.

pub fn is_composite(&self, gid: u16) -> bool

True when glyph gid is a composite (built from component glyphs).

pub fn glyph_components(&self, gid: u16) -> Vec<u16>

Component glyph ids referenced by a composite glyph (for transitive subsetting). Empty for simple or empty glyphs.

pub fn advance_width(&self, gid: u16) -> u16

The advance width of glyph gid in design units. Glyphs past the hmtx metric run share the last advance (monospaced trailing run).

pub fn left_side_bearing(&self, gid: u16) -> i16

The left side bearing of glyph gid in design units. Glyphs past the long-metric run share the last advance but keep their own trailing LSB.

pub fn glyph_index(&self, ch: char) -> u16

The glyph id for a character, or 0 (.notdef) if unmapped.

pub fn advance_1000(&self, ch: char) -> u32

Advance width of ch in 1/1000 em (PDF text-space units). An unmapped ch resolves to glyph 0 (.notdef) and reserves that glyph’s advance (so a tofu box still occupies its natural width); only an unparsable face with units_per_em == 0 yields 0.

pub fn kerning_between_glyphs(&self, left: u16, right: u16) -> i16

Kerning adjustment between two glyph ids in design units.

Unsupported or absent kerning tables return zero. This currently supports legacy TrueType/Microsoft kern table version 0, format 0, horizontal pairs. GPOS pair positioning is tracked separately.

pub fn kerning(&self, left: char, right: char) -> i16

Kerning adjustment between two characters in design units.

pub fn kerning_1000(&self, left: char, right: char) -> i32

Kerning adjustment between two characters in 1/1000 em units.

pub fn subset(&self, keep: &[char]) -> Option<Vec<u8>>

Build a new, minimal, valid TrueType (glyf) font containing glyph 0 (.notdef) plus exactly the glyphs needed to render keep (mapped through the original cmap), transitively closing over composite components. Returns a fresh sfnt (0x00010000) suitable for a PDF FontFile2, or None on any failure (missing glyf/loca/required table, or a malformed read).

pub fn subset_glyphs( &self, glyphs: &[u16], cmap_chars: &[char], ) -> Option<(Vec<u8>, BTreeMap<u16, u16>)>

Subset to an explicit glyph set (the closure still pulls in composite components), building the cmap from cmap_chars. Returns the font bytes plus the old->new glyph id remap — for callers that pre-shaped a glyph sequence (e.g. GSUB ligatures) and must emit the renumbered ids.

Errors

Returns None for a font without glyf/loca outlines or on a malformed read (same conditions as Font::subset).

impl Font

pub fn gpos_kerning(&self) -> Kerning

Parses the GPOS kern feature once into a Kerning structure.

Returns an empty Kerning (every pair() -> 0) when the font has no GPOS table, no kern feature, or the relevant offsets are malformed.

impl Font

pub fn gsub_ligatures(&self) -> Ligatures

Parse the GSUB liga standard-ligature substitutions once.

Returns empty Ligatures when the font has no GSUB / no liga feature or the relevant offsets are malformed.

Trait Implementations

impl Clone for Font

fn clone(&self) -> Font

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Font

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

Formats the value using the given formatter.