Module: TTFunk::Table::Cmap::Format00

Defined in:
lib/ttfunk/table/cmap/format00.rb

Overview

Format 0: Byte encoding table.

This module conditionally extends Subtable.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#code_mapArray<Integer> (readonly)

Code map.

Returns:

  • (Array<Integer>)
Source Code
lib/ttfunk/table/cmap/format00.rb, line 16
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def code_map
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  @code_map
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end

#languageInteger (readonly)

Language.

Returns:

  • (Integer)
Source Code
lib/ttfunk/table/cmap/format00.rb, line 12
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def language
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  @language
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end

Class Method Details

.encode(charmap) ⇒ Hash

Encode the encoding record to format 0.

Parameters:

  • charmap (Hash{Integer => Integer})

    a hash mapping character codes to glyph ids (where the glyph ids are from the original font).

Returns:

  • (Hash)
    • :charmap (Hash{Integer => Hash}) keys are the characrers in charset, values are hashes:
      • :old (Integer) - glyph ID in the original font.
      • :new (Integer) - glyph ID in the subset font. that maps the characters in charmap to a
    • :subtable (String) - serialized encoding record.
    • :max_glyph_id (Integer) - maximum glyph ID in the new font.
Source Code
lib/ttfunk/table/cmap/format00.rb, line 30
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def self.encode(charmap)
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  next_id = 0
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  glyph_indexes = Array.new(256, 0)
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  glyph_map = { 0 => 0 }
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  new_map =
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    charmap.keys.sort.each_with_object({}) do |code, map|
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      glyph_map[charmap[code]] ||= next_id += 1
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      map[code] = { old: charmap[code], new: glyph_map[charmap[code]] }
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      glyph_indexes[code] = glyph_map[charmap[code]]
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      map
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    end
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  # format, length, language, indices
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  subtable = [0, 262, 0, *glyph_indexes].pack('nnnC*')
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  { charmap: new_map, subtable: subtable, max_glyph_id: next_id + 1 }
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end

Instance Method Details

#[](code) ⇒ Integer

Get glyph ID for character code.

Parameters:

  • code (Integer)

    character code.

Returns:

  • (Integer)

    glyph ID.

Source Code
lib/ttfunk/table/cmap/format00.rb, line 53
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def [](code)
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  @code_map[code] || 0
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end

#supported?true

Is this encoding record format supported?

Returns:

  • (true)
Source Code
lib/ttfunk/table/cmap/format00.rb, line 60
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def supported?
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  true
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end