Struct MockFont 

pub struct MockFont {
    pub font_metrics: LayoutFontMetrics,
    pub space_width: Option<usize>,
    pub glyph_advances: BTreeMap<u16, u16>,
    pub glyph_sizes: BTreeMap<u16, (i32, i32)>,
    pub glyph_indices: BTreeMap<u32, u16>,
}

A mock font implementation for testing text layout without real fonts.

This allows testing text shaping, layout, and rendering code paths without needing to load actual TrueType/OpenType font files.

Fields

font_metrics: LayoutFontMetrics

Font metrics (ascent, descent, etc.).

space_width: Option<usize>

Width of the space character in font units.

glyph_advances: BTreeMap<u16, u16>

Horizontal advance widths keyed by glyph ID.

glyph_sizes: BTreeMap<u16, (i32, i32)>

Glyph bounding box sizes (width, height) keyed by glyph ID.

glyph_indices: BTreeMap<u32, u16>

Unicode codepoint to glyph ID mapping.

Implementations

impl MockFont

pub fn new(font_metrics: LayoutFontMetrics) -> Self

Creates a new MockFont with the given font metrics.

pub fn with_space_width(self, width: usize) -> Self

Sets the space character width.

pub fn with_glyph_advance(self, glyph_index: u16, advance: u16) -> Self

Adds a horizontal advance value for a glyph.

pub fn with_glyph_size(self, glyph_index: u16, size: (i32, i32)) -> Self

Adds a bounding box size for a glyph.

pub fn with_glyph_index(self, unicode: u32, index: u16) -> Self

Adds a Unicode codepoint to glyph ID mapping.

Trait Implementations

impl Clone for MockFont

fn clone(&self) -> MockFont

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MockFont

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

Formats the value using the given formatter.