Font Collections

Fontisan supports font collections (TTC, OTC, dfont) with pack, unpack, and format conversion capabilities.

Overview

Format	Description	Font Types
TTC	TrueType Collection	TrueType fonts only
OTC	OpenType Collection	CFF/OpenType fonts only
dfont	Apple Data Fork Font	Mixed TrueType and CFF

Listing Fonts in Collections

CLI

# List fonts in a collection
fontisan ls fonts.ttc

# Output example:
# Collection: fonts.ttc
# Fonts: 2
#
# 0. Helvetica Regular
#    PostScript: Helvetica-Regular
#    Format: TrueType
#    Glyphs: 268, Tables: 14
#
# 1. Helvetica Bold
#    PostScript: Helvetica-Bold
#    Format: TrueType
#    Glyphs: 268, Tables: 14

API

collection = Fontisan::FontLoader.load('fonts.ttc')

collection.each_with_index do |font, index|
  puts "#{index}. #{font.family_name} #{font.style}"
end

Extracting Fonts (Unpack)

CLI

# Extract all fonts from collection
fontisan unpack fonts.ttc --output-dir ./extracted

# Extract specific font by index
fontisan unpack fonts.ttc --index 0 --output first.ttf

# Extract with format conversion
fontisan unpack fonts.ttc --output-dir ./extracted --format otf

API

collection = Fontisan::FontLoader.load('fonts.ttc')

collection.each_with_index do |font, index|
  output = "extracted/font-#{index}.ttf"
  Fontisan::FontWriter.write(font, output)
end

Creating Collections (Pack)

CLI

# Pack fonts into TTC
fontisan pack font1.ttf font2.ttf font3.ttf --output family.ttc

# Pack with deduplication
fontisan pack font1.ttf font2.ttf --output family.ttc --deduplicate

# Pack as OTC (OpenType collection)
fontisan pack font1.otf font2.otf --output family.otc

API

fonts = [
  Fontisan::FontLoader.load('regular.ttf'),
  Fontisan::FontLoader.load('bold.ttf'),
  Fontisan::FontLoader.load('italic.ttf')
]

Fontisan::CollectionWriter.pack(fonts, 'family.ttc')

Collection Conversions

TTC → OTC

Fontisan::ConversionOptions.recommended(from: :ttc, to: :otc)
# opening: { convert_curves: true, decompose_composites: false, autohint: false }
# generating: { target_format: "otf", decompose_on_output: false,
#              hinting_mode: "preserve" }

Converts all TrueType fonts to OpenType/CFF, then repacks as OTC.

fontisan convert family.ttc --to otc --output family.otc --target-format otf

OTC → TTC

Fontisan::ConversionOptions.recommended(from: :otc, to: :ttc)
# opening: { convert_curves: true, decompose_composites: false, interpret_ot: true }
# generating: { target_format: "ttf", decompose_on_output: false,
#              hinting_mode: "auto" }

Converts all OpenType/CFF fonts to TrueType, then repacks as TTC.

fontisan convert family.otc --to ttc --output family.ttc --target-format ttf

TTC/OTC → dfont

Fontisan::ConversionOptions.recommended(from: :ttc, to: :dfont)
# opening: {}
# generating: { target_format: "preserve", decompose_on_output: false,
#              write_custom_tables: true }

Notes: dfont supports both TrueType and OpenType/CFF, or mixed formats.

fontisan convert family.ttc --to dfont --output family.dfont

Table Sharing

Collections share common tables to reduce file size:

• cmap — Character mappings
• loca — Glyph locations (TrueType)
• maxp — Maximum profile
• name — Font names
• post — PostScript names

Analyzing Table Sharing

fontisan info fonts.ttc

# Output includes:
# Table Sharing Statistics:
#   Shared tables: 4
#   Unique tables per font: 10
#   Space saved: 45%

Deduplication

When packing collections, Fontisan can deduplicate tables:

fontisan pack font1.ttf font2.ttf --output family.ttc --deduplicate

How It Works

1. Analyze all tables across fonts
2. Identify identical tables by checksum
3. Share tables where possible
4. Reduce overall file size

Presets

archive_to_modern

Convert font archives to modern format:

Fontisan::ConversionOptions.from_preset(:archive_to_modern)
# From: :ttc, To: :otf
# opening: { convert_curves: true, decompose_composites: false }
# generating: { target_format: "otf", hinting_mode: "preserve" }

Use cases:

• Extracting fonts from TTC archives
• Standardizing collection formats
• Converting legacy font collections

Examples

Extract and Convert Collection

# Extract all fonts as OTF
fontisan unpack fonts.ttc --output-dir ./family --format otf

# Results in:
# family/font-0.otf
# family/font-1.otf
# family/font-2.otf

Convert Collection Format

# Convert TTC to OTC
fontisan convert truetype-collection.ttc --to otc \
  --output opentype-collection.otc \
  --target-format otf \
  --hinting-mode auto

Merge Multiple Collections

# Load multiple collections
collection1 = Fontisan::FontLoader.load('set1.ttc')
collection2 = Fontisan::FontLoader.load('set2.ttc')

# Combine fonts
all_fonts = collection1.to_a + collection2.to_a

# Pack as new collection
Fontisan::CollectionWriter.pack(all_fonts, 'combined.ttc')

Optimize Collection

# Pack with deduplication
fontisan pack *.ttf --output optimized.ttc --deduplicate

# Check space savings
fontisan info optimized.ttc