Class: Fontisan::Woff2Collection

Inherits:
Object
  • Object
show all
Includes:
Collection::SharedLogic
Defined in:
lib/fontisan/woff2_collection.rb

Overview

WOFF2 font collection (spec section 4.2).

Wraps a WOFF2 collection file (flavor='ttcf') and exposes the same interface as TrueTypeCollection/OpenTypeCollection so collection consumers don't need to know which container format they're holding.

Unlike TTC/OTC (which subclass BaseCollection for BinData parsing), WOFF2 collections are decoded eagerly via Woff2::CollectionDecoder because the per-font tables require Brotli decompression + glyf/loca reconstruction before they can be returned.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Collection::SharedLogic

#calculate_table_sharing_for_fonts

Constructor Details

#initialize(data) ⇒ Woff2Collection

Returns a new instance of Woff2Collection.

Parameters:

  • data (String) —

    WOFF2 collection binary



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# File 'lib/fontisan/woff2_collection.rb', line 23

def initialize(data)
  @data = data.force_encoding(Encoding::BINARY)
end

Instance Attribute Details

#data ⇒ String (readonly)

Returns Source WOFF2 binary.

Returns:

  • (String) —

    Source WOFF2 binary



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# File 'lib/fontisan/woff2_collection.rb', line 20

def data
  @data
end

Class Method Details

.from_file(path) ⇒ Woff2Collection

Load a WOFF2 collection from a file path.

Parameters:

  • path (String)

Returns:



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# File 'lib/fontisan/woff2_collection.rb', line 31

def self.from_file(path)
  new(File.binread(path))
end

Instance Method Details

#collection? ⇒ Boolean

Whether this object represents a font collection. WOFF2 collections are always collections.

Returns:

  • (Boolean) 


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# File 'lib/fontisan/woff2_collection.rb', line 78

def collection? = true

#extract_fonts(_io = nil) ⇒ Array<TrueTypeFont, OpenTypeFont>

Extract every font in the collection.

Parameters:

  • _io (IO, nil) (defaults to: nil) —

    Ignored — WOFF2 collections decode in memory.

Returns:



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# File 'lib/fontisan/woff2_collection.rb', line 57

def extract_fonts(_io = nil)
  decoded.map { |entry| build_font(entry) }
end

#font(index, _io = nil, _mode: LoadingModes::FULL) ⇒ TrueTypeFont, ...

Get a single font by index.

Parameters:

  • index (Integer) —

    0-based font index

  • _io (IO, nil) (defaults to: nil) —

    Ignored.

  • _mode (Symbol) (defaults to: LoadingModes::FULL) —

    Ignored — full mode only (WOFF2 collections are decoded eagerly).

Returns:



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# File 'lib/fontisan/woff2_collection.rb', line 68

def font(index, _io = nil, _mode: LoadingModes::FULL)
  return nil if index >= num_fonts

  build_font(decoded[index])
end

#font_offsets ⇒ Array<Integer>

Per-font synthetic offsets. WOFF2 collections don't have byte offsets like TTC (each font is reconstructed in memory); the index is the only identifier. Returned for compatibility with BaseCollection's interface.

Returns:

  • (Array<Integer>) —

    0..num_fonts-1



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# File 'lib/fontisan/woff2_collection.rb', line 49

def font_offsets
  (0...num_fonts).to_a
end

#format ⇒ Symbol

High-level pipeline format identifier. Owned by the collection class so the conversion pipeline can dispatch without case statements.

Returns:

  • (Symbol) —

    :woff2_collection



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# File 'lib/fontisan/woff2_collection.rb', line 99

def format = :woff2_collection

#num_fonts ⇒ Integer Also known as: font_count

Number of fonts in the collection.

Returns:

  • (Integer) 


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# File 'lib/fontisan/woff2_collection.rb', line 38

def num_fonts
  decoded.length
end

#table_names ⇒ Array<String>

Collections have no single SFNT table directory.

Returns:

  • (Array<String>) —

    empty



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# File 'lib/fontisan/woff2_collection.rb', line 83

def table_names = []

#valid? ⇒ Boolean

Validate format correctness.

Returns:

  • (Boolean) 


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# File 'lib/fontisan/woff2_collection.rb', line 88

def valid?
  flavor = @data[4, 4].unpack1("N")
  flavor == Woff2::CollectionDecoder::TTC_FLAVOR
rescue StandardError
  false
end