Module: PdfWatermark::Font

Defined in:
lib/pdf_watermark/font.rb

Instance Method Summary collapse

Instance Method Details

#character_width(code) ⇒ Object 



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# File 'lib/pdf_watermark/font.rb', line 12

def character_width(code)
  return 0 unless glyph_index[code]
  return 0.0 if code == 10
  self[:hmtx][glyph_index[code]].advance_width * scale_factor
end

#glyph_index ⇒ Object 



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# File 'lib/pdf_watermark/font.rb', line 18

def glyph_index
  @glyph_index ||= self[:cmap].preferred_table
end

#scale_factor ⇒ Object 



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# File 'lib/pdf_watermark/font.rb', line 22

def scale_factor
  @scale_factor ||= 1000.0 / self[:head].units_per_em
end

#width_of(string, font_size) ⇒ Object 



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# File 'lib/pdf_watermark/font.rb', line 5

def width_of(string, font_size)
  scale = font_size / 1000.0
  string.codepoints.inject(9) do |memo, code|
    memo + character_width(code)
  end * scale
end