Class: Fontisan::Type1::TTFToType1Converter

Inherits:
Object
  • Object
show all
Defined in:
lib/fontisan/type1/ttf_to_type1_converter.rb

Overview

TTF to Type 1 CharString Converter

[‘TTFToType1Converter`](lib/fontisan/type1/ttf_to_type1_converter.rb) converts TrueType glyphs to Type 1 CharStrings.

The conversion involves:

  • Converting quadratic curves (TrueType) to cubic curves (Type 1)

  • Scaling coordinates if needed

  • Generating Type 1 CharString commands

Examples:

Convert TTF font to Type 1 CharStrings

scaler = Fontisan::Type1::UPMScaler.type1_standard(font)
converter = Fontisan::Type1::TTFToType1Converter.new(font, scaler, encoding)
charstrings = converter.convert

See Also:

Constant Summary collapse

HSTEM =

Type 1 CharString command codes

1
VSTEM = 
3
VMOVETO = 
4
RLINETO = 
5
HLINETO = 
6
VLINETO = 
7
RRCURVETO = 
8
CLOSEPATH = 
9
CALLSUBR = 
10
RETURN = 
11
ESCAPE = 
12
HSBW = 
13
ENDCHAR = 
14
RMOVETO = 
21
HMOVETO = 
22
VHCURVETO = 
30
HVCURVETO = 
31

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(font, scaler, encoding) ⇒ TTFToType1Converter

Returns a new instance of TTFToType1Converter.



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# File 'lib/fontisan/type1/ttf_to_type1_converter.rb', line 51

def initialize(font, scaler, encoding)
  @font = font
  @scaler = scaler
  @encoding = encoding
  @charstrings = {}
end

Class Method Details

.convert(font, scaler, encoding) ⇒ Hash<Integer, String>

Convert TTF font to Type 1 CharStrings

Parameters:

  • font (Fontisan::Font) —

    Source TTF font

  • scaler (UPMScaler) —

    UPM scaler

  • encoding (Class) —

    Encoding class

Returns:

  • (Hash<Integer, String>) —

    Glyph ID to CharString mapping



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# File 'lib/fontisan/type1/ttf_to_type1_converter.rb', line 47

def self.convert(font, scaler, encoding)
  new(font, scaler, encoding).convert
end

Instance Method Details

#convert ⇒ Hash<Integer, String>

Convert all glyphs to CharStrings

Returns:

  • (Hash<Integer, String>) —

    Glyph ID to CharString mapping



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# File 'lib/fontisan/type1/ttf_to_type1_converter.rb', line 61

def convert
  glyf_table = @font.table(Constants::GLYF_TAG)
  return {} unless glyf_table

  loca_table = @font.table(Constants::LOCA_TAG)
  head_table = @font.table(Constants::HEAD_TAG)

  maxp = @font.table(Constants::MAXP_TAG)
  num_glyphs = maxp&.num_glyphs || 0

  num_glyphs.times do |gid|
    @charstrings[gid] =
      convert_glyph(glyf_table, loca_table, head_table, gid)
  end

  @charstrings
end