Struct LayoutResult 

pub struct LayoutResult {
    pub glyphs: Vec<PositionedGlyph>,
    pub lines: Vec<Line>,
    pub metrics: ParagraphMetrics,
    pub decorations: Vec<DecorationRect>,
    pub inline_objects: Vec<PositionedInlineObject>,
}

The structured result of a layout pass.

Fields

glyphs: Vec<PositionedGlyph>

All positioned glyphs in logical (reading) order.

lines: Vec<Line>

Line records indexing into Self::glyphs.

metrics: ParagraphMetrics

Aggregate metrics.

decorations: Vec<DecorationRect>

Decoration rectangles computed from the layout (underlines, overlines, strikethroughs). Empty unless decorations are requested via crate::options::LayoutOptions::decoration.

inline_objects: Vec<PositionedInlineObject>

Positioned inline objects (images, widgets) placed during layout.

Implementations

impl LayoutResult

pub fn hit_test(&self, x: f32, y: f32) -> Option<(usize, usize, u32)>

Find the glyph nearest to pixel coordinates (x, y) for hit-testing and cursor placement during text selection.

Returns Some((line_index, glyph_index_within_line, cluster_byte_offset)) where:

• line_index is the index into LayoutResult::lines,
• glyph_index_within_line is the 0-based position within that line’s glyph range (i.e. 0 is the first glyph of the line),
• cluster_byte_offset is PositionedGlyph::cluster — the UTF-8 byte offset of the glyph’s source character.

If (x, y) falls outside all lines the nearest line is chosen. If it falls outside all glyphs on the chosen line the nearest endpoint glyph is returned.

Returns None only when self.lines is empty.

pub fn unique_glyphs_for_atlas(&self) -> Vec<(u16, f32)>

Return the unique (glyph_id, font_size) pairs present in this layout, suitable for pre-warming an SDF atlas or batching rasterisation.

Each (gid, px_size) pair appears exactly once regardless of how many times that glyph occurs in the layout. The order of the returned entries is stable: pairs are emitted in the order their first occurrence is encountered when iterating Self::glyphs from index 0.

The font_size_bits value stored internally as a u32 key is obtained via font_size.to_bits() so that equal IEEE-754 floats are always treated as equal keys even in a HashSet.

Rasteriser usage

for (glyph_id, px_size) in layout.unique_glyphs_for_atlas() {
    atlas.pre_warm(glyph_id, px_size);
}

pub fn rasterization_inputs(&self) -> Vec<(u16, f32, f32, f32)>

Return per-glyph (glyph_id, x, y, font_size) tuples ready for direct handoff to a rasteriser.

Positions are in pixel coordinates with the origin at the top-left of the text block (matching PositionedGlyph::pos). The returned Vec preserves logical (reading) order and contains exactly one entry per glyph in Self::glyphs.

Rasteriser usage

for (gid, x, y, px_size) in layout.rasterization_inputs() {
    rasterizer.draw(gid, x, y, px_size);
}

pub fn sdf_glyph_set(&self) -> Vec<(u16, f32)>

Returns the set of glyphs that should be pre-loaded into an SDF atlas before rendering. Each entry is (glyph_id, px_size).

This is an alias for Self::unique_glyphs_for_atlas with an SDF-oriented name for use at the oxitext-sdf integration boundary.

Usage with oxitext-sdf

let layout = engine.layout(text, runs, &constraints, alignment, None)?;
for (glyph_id, px_size) in layout.sdf_glyph_set() {
    if let Ok(Some(tile)) =
        oxitext_sdf::glyph_to_sdf_tile(font_data, glyph_id, px_size, 64, 4.0)
    {
        atlas.pack_tile(tile);
    }
}

Trait Implementations

impl Clone for LayoutResult

fn clone(&self) -> LayoutResult

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LayoutResult

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

Formats the value using the given formatter.