ConversionOptions

Type-safe conversion configuration.

Overview

Fontisan::ConversionOptions provides a type-safe way to configure font conversions.

Class Methods

recommended(from:, to:)

Get recommended options for a conversion type.

options = Fontisan::ConversionOptions.recommended(from: :ttf, to: :otf)
# => #<Fontisan::ConversionOptions ...>

# Access settings
options.opening   # => { convert_curves: true, ... }
options.generating # => { hinting_mode: "auto", ... }

Parameters:

Name	Type	Description
from	Symbol	Source format
to	Symbol	Target format

from_preset(name)

Load options from a named preset.

# Web optimization preset
options = Fontisan::ConversionOptions.from_preset(:web_optimized)

# Type 1 to modern
options = Fontisan::ConversionOptions.from_preset(:type1_to_modern)

Available Presets:

Preset	From	To
type1_to_modern	Type 1	OTF
modern_to_type1	OTF	Type 1
web_optimized	OTF	WOFF2
legacy_web	OTF	WOFF
archive_to_modern	TTC	OTF

new(**kwargs)

Create custom options.

options = Fontisan::ConversionOptions.new(
  from: :ttf,
  to: :otf,
  opening: {
    convert_curves: true,
    autohint: true
  },
  generating: {
    hinting_mode: 'auto',
    optimize_tables: true
  }
)

Instance Attributes

opening

Opening options control source font processing.

Option	Type	Default
decompose_composites	Boolean	false
convert_curves	Boolean	true
scale_to_1000	Boolean	false
scale_from_1000	Boolean	false
autohint	Boolean	false
generate_unicode	Boolean	false
store_custom_tables	Boolean	true
store_native_hinting	Boolean	false
interpret_ot	Boolean	false
read_all_records	Boolean	false
preserve_encoding	String	nil

generating

Generating options control output font writing.

Option	Type	Default	Applies to
write_pfm	Boolean	false	Type 1 output
write_afm	Boolean	false	Type 1 output
write_inf	Boolean	false	Type 1 output
select_encoding_automatically	Boolean	false	Type 1 output
hinting_mode	String	'preserve'	All outline conversions
decompose_on_output	Boolean	false	All outline conversions
write_custom_tables	Boolean	true	All
optimize_tables	Boolean	false	All
zlib_level	Integer (0–9)	6	WOFF only
uncompressed	Boolean	false	WOFF only
compression_threshold	Integer (bytes)	100	WOFF only
brotli_quality	Integer (0–11)	11	WOFF2 only
transform_tables	Boolean	false	WOFF2 only
metadata_xml	String	nil	WOFF only
private_data	String	nil	WOFF only
preserve_metadata	Boolean	true	All

Compression knobs are declared by each strategy (WoffWriter, Woff2Encoder) via the ConversionStrategy DSL. FormatConverter.validate_options_for_target! rejects knobs that don't apply to the requested target format.

Examples

Basic Conversion

options = Fontisan::ConversionOptions.recommended(from: :ttf, to: :otf)
converter = Fontisan::Converters::OutlineConverter.new
result = converter.convert(font, options: options)

Web Optimization

options = Fontisan::ConversionOptions.from_preset(:web_optimized)
Fontisan::FontWriter.write(font, 'output.woff2', options: options)

Custom Options

options = Fontisan::ConversionOptions.new(
  from: :ttf,
  to: :woff2,
  opening: { autohint: true },
  generating: {
    hinting_mode: 'auto',
    optimize_tables: true,
    brotli_quality: 11,
    transform_tables: true
  }
)

WOFF with Max zlib (Legacy Browser Reach)

options = Fontisan::ConversionOptions.new(
  from: :ttf,
  to: :woff,
  generating: { zlib_level: 9, preserve_metadata: true }
)