TrueType (TTF)

TrueType is a standard font format using quadratic Bézier curves.

Overview

• Curve Type: Quadratic Bézier
• Hinting: TrueType instructions
• Storage: glyf + loca tables

Key Tables

Table	Purpose
head	Font header
hhea	Horizontal header
maxp	Maximum profile
name	Name records
cmap	Character mapping
glyf	Glyph outlines
loca	Glyph locations
hmtx	Horizontal metrics
post	PostScript names
prep	Control Value Program
fpgm	Font Program
cvt	Control Value Table

Loading

font = Fontisan::FontLoader.load('font.ttf')

# Access tables
head = font.tables['head']
glyf = font.tables['glyf']

puts "Units per Em: #{head.units_per_em}"
puts "Glyphs: #{font.tables['maxp'].num_glyphs}"

Glyph Outlines

glyph = font.glyphs[42]

# Access outline
glyph.contours.each do |contour|
  contour.points.each do |point|
    if point.on_curve?
      puts "Point at (#{point.x}, #{point.y})"
    else
      puts "Control at (#{point.x}, #{point.y})"
    end
  end
end

Hinting

TrueType fonts use bytecode instructions:

prep = font.tables['prep']
fpgm = font.tables['fpgm']
cvt = font.tables['cvt']

if prep
  puts "Prep program: #{prep.bytecode.length} bytes"
end

if cvt
  puts "CVT entries: #{cvt.values.length}"
end

Converting

TTF to OTF

fontisan convert font.ttf --to otf --output font.otf

TTF to WOFF2

fontisan convert font.ttf --to woff2 --output font.woff2

Characteristics

Advantages

• Wide support — All platforms
• Excellent hinting — TrueType instructions
• Variable fonts — gvar support

Limitations

• Larger file size — Compared to CFF
• Quadratic curves — More points for complex shapes