Class: Grawlix::GlyphSizeCache

Inherits:
Object
  • Object
show all
Defined in:
lib/grawlix/glyph_size_cache.rb

Constant Summary collapse

DEFAULT_FONT_PATH = 
File.join(File.dirname(__FILE__), '..', '..', 'OpenSans-Regular.ttf')

Instance Method Summary collapse

Constructor Details

#initialize(font_path = DEFAULT_FONT_PATH) ⇒ GlyphSizeCache

Returns a new instance of GlyphSizeCache.



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# File 'lib/grawlix/glyph_size_cache.rb', line 7

def initialize(font_path = DEFAULT_FONT_PATH)
  @file = TTFunk::File.open(font_path)
  @cache = {}
end

Instance Method Details

#em_size ⇒ Object 



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# File 'lib/grawlix/glyph_size_cache.rb', line 16

def em_size
  @em ||= @file.header.units_per_em
end

#width_for(character) ⇒ Object 



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# File 'lib/grawlix/glyph_size_cache.rb', line 12

def width_for(character)
  @cache[character] ||= @file.horizontal_metrics.for(@file.cmap.unicode.first[character.unpack("U*").first]).advance_width.to_f / em_size
end