Class: Fontisan::Ufo::Glyph

Inherits:
Object
  • Object
show all
Defined in:
lib/fontisan/ufo/glyph.rb

Overview

A glyph in a UFO source. Holds contours, components, anchors, guidelines, images, unicode codepoints, advance width/height, and a custom-data bag (lib).

The .glif XML format has multiple revisions (1, 2, 3); the parser accepts all of them.

Constant Summary collapse

DEFAULT_UNITS_PER_EM =

OpenType requires GID 0 to be a glyph named .notdef. UFO sources that lack an explicit .notdef (synthetic SVG donors, programmatic sources) need one injected before compile. This constant is the default width used for that injected glyph, and doubles as the fallback unitsPerEm in Head.build when UFO info omits the field. Single source of truth for both call sites.

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Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name:) ⇒ Glyph

Returns a new instance of Glyph.



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# File 'lib/fontisan/ufo/glyph.rb', line 42

def initialize(name:)
  @name = name.to_s
  @unicodes = []
  @width = 0.0
  @height = 0.0
  @contours = []
  @components = []
  @anchors = []
  @guidelines = []
  @images = []
  @note = nil
  @lib = Lib.new
end

Instance Attribute Details

#anchors ⇒ Object (readonly)

Returns the value of attribute anchors.



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# File 'lib/fontisan/ufo/glyph.rb', line 39

def anchors
  @anchors
end

#components ⇒ Object (readonly)

Returns the value of attribute components.



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# File 'lib/fontisan/ufo/glyph.rb', line 39

def components
  @components
end

#contours ⇒ Object (readonly)

Returns the value of attribute contours.



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# File 'lib/fontisan/ufo/glyph.rb', line 39

def contours
  @contours
end

#guidelines ⇒ Object (readonly)

Returns the value of attribute guidelines.



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# File 'lib/fontisan/ufo/glyph.rb', line 39

def guidelines
  @guidelines
end

#height ⇒ Object

Returns the value of attribute height.



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# File 'lib/fontisan/ufo/glyph.rb', line 38

def height
  @height
end

#images ⇒ Object (readonly)

Returns the value of attribute images.



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# File 'lib/fontisan/ufo/glyph.rb', line 39

def images
  @images
end

#lib ⇒ Object

Returns the value of attribute lib.



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# File 'lib/fontisan/ufo/glyph.rb', line 38

def lib
  @lib
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/fontisan/ufo/glyph.rb', line 39

def name
  @name
end

#note ⇒ Object

Returns the value of attribute note.



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# File 'lib/fontisan/ufo/glyph.rb', line 38

def note
  @note
end

#unicodes ⇒ Object (readonly)

Returns the value of attribute unicodes.



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# File 'lib/fontisan/ufo/glyph.rb', line 39

def unicodes
  @unicodes
end

#width ⇒ Object

Returns the value of attribute width.



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# File 'lib/fontisan/ufo/glyph.rb', line 38

def width
  @width
end

Class Method Details

.from_glif(xml) ⇒ Glyph

Returns parsed glyph.

Parameters:

  • xml (String) —

    the .glif XML body

Returns:

  • (Glyph) —

    parsed glyph



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# File 'lib/fontisan/ufo/glyph.rb', line 112

def self.from_glif(xml)
  doc = Nokogiri::XML(xml)
  root = doc.root
  new(name: root["name"]).tap { |g| g.read_from(root) }
end

.notdef(units_per_em: nil) ⇒ Glyph

Synthesize an empty .notdef glyph suitable for GID 0.

OpenType mandates GID 0 be .notdef. UFO sources that lack an explicit .notdef (synthetic SVG donors, programmatic sources) need one injected before compile. The width defaults to the font's units_per_em so the .notdef consumes one em of advance.

Parameters:

  • units_per_em (Integer, nil) (defaults to: nil) —

    Advance width for the synthesized glyph. Defaults to DEFAULT_UNITS_PER_EM when nil.

Returns:



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# File 'lib/fontisan/ufo/glyph.rb', line 32

def self.notdef(units_per_em: nil)
  new(name: ".notdef").tap do |g|
    g.width = units_per_em&.to_i || DEFAULT_UNITS_PER_EM
  end
end

Instance Method Details

#add_anchor(anchor) ⇒ Object 



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# File 'lib/fontisan/ufo/glyph.rb', line 70

def add_anchor(anchor)
  @anchors << anchor
  anchor
end

#add_component(component) ⇒ Object 



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# File 'lib/fontisan/ufo/glyph.rb', line 65

def add_component(component)
  @components << component
  component
end

#add_contour(contour) ⇒ Object 



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# File 'lib/fontisan/ufo/glyph.rb', line 60

def add_contour(contour)
  @contours << contour
  contour
end

#add_guideline(guideline) ⇒ Object 



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# File 'lib/fontisan/ufo/glyph.rb', line 75

def add_guideline(guideline)
  @guidelines << guideline
  guideline
end

#add_image(image) ⇒ Object 



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# File 'lib/fontisan/ufo/glyph.rb', line 80

def add_image(image)
  @images << image
  image
end

#add_unicode(codepoint) ⇒ Object 



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# File 'lib/fontisan/ufo/glyph.rb', line 56

def add_unicode(codepoint)
  @unicodes << codepoint.to_i
end

#bbox ⇒ BoundingBox?

Returns axis-aligned bbox of contours.

Returns:

  • (BoundingBox, nil) —

    axis-aligned bbox of contours.



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# File 'lib/fontisan/ufo/glyph.rb', line 96

def bbox
  return nil if @contours.empty?

  points = @contours.flat_map(&:points)
  return nil if points.empty?

  BoundingBox.new(
    x_min: points.map(&:x).min,
    y_min: points.map(&:y).min,
    x_max: points.map(&:x).max,
    y_max: points.map(&:y).max,
  )
end

#composite? ⇒ Boolean

Composite glyphs reference other glyphs via components.

Returns:

  • (Boolean) 


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# File 'lib/fontisan/ufo/glyph.rb', line 86

def composite?
  !@components.empty?
end

#point_count ⇒ Object

Total number of points across all contours.



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# File 'lib/fontisan/ufo/glyph.rb', line 91

def point_count
  @contours.sum(&:point_count)
end

#read_from(root) ⇒ Object

Populate this glyph from a Nokogiri node.



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# File 'lib/fontisan/ufo/glyph.rb', line 134

def read_from(root)
  read_advance(root)
  read_unicodes(root)
  read_outline(root)
  read_anchors(root)
  read_guidelines(root)
  read_image(root)
  read_lib(root)
  read_note(root)
end

#to_glif ⇒ String

Render this glyph back to .glif XML.

Returns:

  • (String) —

    XML text



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# File 'lib/fontisan/ufo/glyph.rb', line 120

def to_glif
  builder = Nokogiri::XML::Builder.new(encoding: "UTF-8") do |xml|
    xml.glyph(name: @name, format: "2") do
      emit_advance(xml)
      emit_unicodes(xml)
      emit_outline(xml)
      emit_lib(xml)
      emit_note(xml)
    end
  end
  builder.to_xml
end

#to_outline ⇒ Fontisan::Models::Outline

Convert this glyph to a fontisan Models::Outline for use by the CFF charstring builder.

UFO contours use cubic Bezier curves ("curve" type with two off-curve controls). Single off-curves are interpreted as quadratic and degree-elevated to cubic.

Returns:



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# File 'lib/fontisan/ufo/glyph.rb', line 153

def to_outline
  commands = []
  bbox_hash = { x_min: 0, y_min: 0, x_max: 0, y_max: 0 }

  @contours.each do |contour|
    next if contour.points.empty?

    points = contour.points
    commands << { type: :move_to, x: points.first.x, y: points.first.y }

    i = 1
    while i < points.size
      pt = points[i]
      if pt.on_curve?
        commands << { type: :line_to, x: pt.x, y: pt.y }
        i += 1
      elsif i + 2 < points.size &&
          !points[i + 1].on_curve? && points[i + 2].on_curve?
        commands << {
          type: :curve_to,
          cx1: points[i].x, cy1: points[i].y,
          cx2: points[i + 1].x, cy2: points[i + 1].y,
          x: points[i + 2].x, y: points[i + 2].y
        }
        i += 3
      elsif i + 1 < points.size && points[i + 1].on_curve?
        prev = points[i - 1]
        nxt = points[i + 1]
        cx1 = prev.x + (2.0 / 3.0) * (pt.x - prev.x)
        cy1 = prev.y + (2.0 / 3.0) * (pt.y - prev.y)
        cx2 = nxt.x + (2.0 / 3.0) * (pt.x - nxt.x)
        cy2 = nxt.y + (2.0 / 3.0) * (pt.y - nxt.y)
        commands << {
          type: :curve_to,
          cx1: cx1, cy1: cy1, cx2: cx2, cy2: cy2,
          x: nxt.x, y: nxt.y
        }
        i += 2
      else
        i += 1
      end
    end

    commands << { type: :close_path }
  end

  bb = bbox
  if bb
    bbox_hash = {
      x_min: bb.x_min.to_i, y_min: bb.y_min.to_i,
      x_max: bb.x_max.to_i, y_max: bb.y_max.to_i
    }
  end

  Fontisan::Models::Outline.new(
    glyph_id: 0,
    commands: commands,
    bbox: bbox_hash,
    width: @width.to_i,
  )
end