Class GlyphBuffer

Namespace

Egami.Fonts.Shaping

Assembly

Egami.Fonts.dll

A reusable buffer of shaped glyphs: glyph ids, the UTF-16 index of the text each came from, glyph flags and positions, in visual order. ShapeRun(ReadOnlySpan<char>, int, int, Font, RunProperties, GlyphBuffer) fills it; reuse one buffer for many runs to avoid allocations.

public sealed class GlyphBuffer

Inheritance

object

GlyphBuffer

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Examples

// One run, one font, as HarfBuzz's hb_shape: ligatures, kerning and marks from the font's GSUB and GPOS.
var font = new Font(face, 24);
var glyphs = new GlyphBuffer();
string text = "office";
TextShaper.ShapeRun(text, 0, text.Length, font, new RunProperties { Script = Script.Latin }, glyphs);

for (int i = 0; i < glyphs.Count; i++)
{
    ushort id = glyphs.GlyphIds[i];
    int cluster = glyphs.Clusters[i];                 // index in text the glyph came from
    GlyphPosition position = glyphs.Positions[i];     // in the font's units (pixels here)
    bool breakable = (glyphs.Flags[i] & GlyphFlags.UnsafeToBreak) == 0;
}

float width = glyphs.Advance;

Remarks

Not thread-safe: one buffer per thread.

Properties

Advance

Gets the run's advance: the sum of the glyphs' horizontal advances.

public float Advance { get; }

Property Value

float

Clusters

Gets the UTF-16 index in the text each glyph's cluster starts at.

public ReadOnlySpan<int> Clusters { get; }

Property Value

ReadOnlySpan<int>

Count

Gets the number of glyphs.

public int Count { get; }

Property Value

int

Flags

Gets each glyph's flags.

public ReadOnlySpan<GlyphFlags> Flags { get; }

Property Value

ReadOnlySpan<GlyphFlags>

GlyphIds

Gets the glyph ids.

public ReadOnlySpan<ushort> GlyphIds { get; }

Property Value

ReadOnlySpan<ushort>

Positions

Gets each glyph's advance and offset, in the units of the font the run was shaped with.

public ReadOnlySpan<GlyphPosition> Positions { get; }

Property Value

ReadOnlySpan<GlyphPosition>

Methods

Clear()

Empties the buffer, keeping its storage.

public void Clear()