Class: Fontisan::Converters::CollectionConverter

Inherits:
Object
  • Object
show all
Defined in:
lib/fontisan/converters/collection_converter.rb

Overview

CollectionConverter handles conversion between collection formats

Main responsibility: Convert between TTC, OTC, and dfont collection formats using a three-step strategy:

  1. Unpack: Extract individual fonts from source collection

  2. Convert: Transform each font’s outline format if requested

  3. Repack: Rebuild collection in target format

Supported conversions:

  • TTC ↔ OTC (preserves mixed TTF+OTF by default)

  • TTC → dfont (repackage)

  • OTC → dfont (repackage)

  • dfont → TTC (preserves mixed formats)

  • dfont → OTC (preserves mixed formats)

Examples:

Convert TTC to OTC (preserve formats)

converter = CollectionConverter.new
result = converter.convert(ttc_path, target_type: :otc, output: 'family.otc')

Convert with ConversionOptions

options = ConversionOptions.recommended(from: :ttc, to: :otc)
converter = CollectionConverter.new
result = converter.convert(ttc_path, target_type: :otc, options: { output: 'family.otc', options: options })

Convert TTC to OTC with outline conversion

converter = CollectionConverter.new
result = converter.convert(ttc_path, target_type: :otc,
                           options: { output: 'family.otc', target_format: 'otf' })

Instance Method Summary collapse

Instance Method Details

#convert(collection_path, target_type:, options: {}) ⇒ Hash

Convert collection to target format

Parameters:

  • collection_path (String) —

    Path to source collection

  • target_type (Symbol) —

    Target collection type (:ttc, :otc, :dfont)

  • options (Hash) (defaults to: {}) —

    Conversion options

Options Hash (options:):

  • :output (String) —

    Output file path (required)

  • :target_format (String) —

    Target outline format: ‘preserve’ (default), ‘ttf’, or ‘otf’

  • :optimize (Boolean) —

    Enable table sharing (default: true, TTC/OTC only)

  • :verbose (Boolean) —

    Enable verbose output (default: false)

  • :options (ConversionOptions) —

    ConversionOptions object

Returns:

  • (Hash) —

    Conversion result with:

    • :input [String] - Input collection path

    • :output [String] - Output collection path

    • :source_type [Symbol] - Source collection type

    • :target_type [Symbol] - Target collection type

    • :num_fonts [Integer] - Number of fonts converted

    • :conversions [Array<Hash>] - Per-font conversion details

Raises:

  • (ArgumentError) —

    if parameters invalid

  • (Error) —

    if conversion fails



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# File 'lib/fontisan/converters/collection_converter.rb', line 60

def convert(collection_path, target_type:, options: {})
  validate_parameters!(collection_path, target_type, options)

  # Extract ConversionOptions if provided
  conv_options = extract_conversion_options(options)

  verbose = options.fetch(:verbose, false)
  output_path = options[:output]

  # Determine target format from ConversionOptions or options hash
  target_format = if conv_options&.generating_option?(:target_format,
                                                      "otf")
                    conv_options.generating[:target_format]
                  else
                    options.fetch(:target_format, "preserve").to_s
                  end

  # Validate target_format
  unless %w[preserve ttf otf].include?(target_format)
    raise ArgumentError,
          "Invalid target_format: #{target_format}. Must be 'preserve', 'ttf', or 'otf'"
  end

  puts "Converting collection to #{target_type.to_s.upcase}..." if verbose

  # Step 1: Unpack - extract fonts from source collection
  puts "  Unpacking fonts from source collection..." if verbose
  fonts, source_type = unpack_fonts(collection_path)

  # Check if conversion is needed
  if source_type == target_type
    puts "  Source and target formats are the same, copying collection..." if verbose
    FileUtils.cp(collection_path, output_path)
    return build_result(collection_path, output_path, source_type,
                        target_type, fonts.size, [])
  end

  # Step 2: Convert - transform fonts if requested
  puts "  Converting #{fonts.size} font(s)..." if verbose
  converted_fonts, conversions = convert_fonts(fonts, source_type,
                                               target_type, options.merge(target_format: target_format),
                                               conv_options)

  # Step 3: Repack - build target collection
  puts "  Repacking into #{target_type.to_s.upcase} format..." if verbose
  repack_fonts(converted_fonts, target_type, output_path, options)

  # Build result
  result = build_result(collection_path, output_path, source_type,
                        target_type, fonts.size, conversions)

  if verbose
    display_result(result)
  end

  result
end