Module: Fontisan::Ufo::Compile::Cff

Defined in:
lib/fontisan/ufo/compile/cff.rb

Overview

Builds the OpenType CFF table from UFO glyphs.

Pipeline:

1. Convert each UFO glyph's contours to a Models::Outline
 (cubic Bezier commands).
2. Encode each outline as a Type 2 charstring via the
 existing `Tables::Cff::CharStringBuilder`.
3. Build the CFF structural INDEXes (Name, Top DICT, String,
 Global Subr, CharStrings) with correct offsets.

The Top DICT references absolute offsets to the charset, charstrings, and private dict. Those offsets depend on the size of everything that comes before them — including the Top DICT itself. We resolve the circular dependency with a fixed-point iteration: build the Top DICT, compute offsets, rebuild the Top DICT with the new offsets, repeat until it converges (typically 2 iterations).

Class Method Summary collapse

Class Method Details

.build(font, glyphs:) ⇒ String

Returns CFF table bytes.

Parameters:

Returns:

  • (String) —

    CFF table bytes



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# File 'lib/fontisan/ufo/compile/cff.rb', line 29

def self.build(font, glyphs:)
  name = font.info.postscript_font_name || font.info.family_name || "Untitled"
  charstrings = glyphs.map { |g| charstring_for(g) }
  private_dict = +""

  layout = compute_layout(name: name, glyphs: glyphs,
                          charstrings: charstrings,
                          private_dict: private_dict)

  assemble(layout: layout)
end