Class: Fontisan::Tables::PostTable

Inherits:
SfntTable
  • Object
show all
Defined in:
lib/fontisan/tables/post_table.rb

Overview

OOP representation of the 'post' (PostScript) table

The post table contains PostScript information, primarily glyph names. Different versions exist (1.0, 2.0, 2.5, 3.0, 4.0) with varying glyph name storage strategies.

This class extends SfntTable to provide post-specific validation and convenience methods for accessing PostScript metrics and glyph names.

Examples:

Accessing post table data

post = font.sfnt_table("post")
post.italic_angle      # => 0.0
post.underline_position # => -100
post.underline_thickness # => 50
post.glyph_name_for(42) # => "A"

Instance Attribute Summary

Attributes inherited from SfntTable

#data, #entry, #font, #parsed

Instance Method Summary collapse

Methods inherited from SfntTable

#available?, #calculate_checksum, #checksum, #data_loaded?, #human_name, #initialize, #inspect, #length, #load_data!, #offset, #parse, #parsed?, #required?, #tag, #to_s, #validate!

Constructor Details

This class inherits a constructor from Fontisan::SfntTable

Instance Method Details

#fixed_pitch? ⇒ Boolean

Check if font is fixed pitch (monospaced)

Returns:

  • (Boolean) —

    true if font is monospaced



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# File 'lib/fontisan/tables/post_table.rb', line 68

def fixed_pitch?
  return false unless parsed

  parsed.is_fixed_pitch == 1
end

#glyph_name_for(glyph_id) ⇒ String?

Get glyph name by ID

Parameters:

  • glyph_id (Integer) —

    Glyph ID

Returns:

  • (String, nil) —

    Glyph name, or nil if not found



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# File 'lib/fontisan/tables/post_table.rb', line 117

def glyph_name_for(glyph_id)
  names = glyph_names
  return nil if glyph_id.negative? || glyph_id >= names.length

  names[glyph_id]
end

#glyph_names ⇒ Array<String>

Get all glyph names

Only available for version 1.0 and 2.0

Returns:

  • (Array<String>) —

    Array of glyph names



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# File 'lib/fontisan/tables/post_table.rb', line 107

def glyph_names
  return [] unless parsed

  parsed.glyph_names || []
end

#has_glyph_names? ⇒ Boolean

Check if glyph names are available

Returns:

  • (Boolean) —

    true if glyph names can be retrieved



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# File 'lib/fontisan/tables/post_table.rb', line 127

def has_glyph_names?
  return false unless parsed

  parsed.has_glyph_names?
end

#italic? ⇒ Boolean

Check if font is italic

Returns:

  • (Boolean) —

    true if italic_angle != 0



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# File 'lib/fontisan/tables/post_table.rb', line 44

def italic?
  angle = italic_angle
  !angle.nil? && angle != 0
end

#italic_angle ⇒ Float?

Get italic angle in degrees

Positive value means counter-clockwise tilt

Returns:

  • (Float, nil) —

    Italic angle in degrees, or nil if not parsed



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# File 'lib/fontisan/tables/post_table.rb', line 35

def italic_angle
  return nil unless parsed

  parsed.italic_angle
end

#max_mem_type1 ⇒ Integer?

Get maximum memory for Type 1 fonts

Returns:

  • (Integer, nil) —

    Maximum memory in bytes, or nil if not parsed



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# File 'lib/fontisan/tables/post_table.rb', line 98

def max_mem_type1
  parsed&.max_mem_type1
end

#max_mem_type42 ⇒ Integer?

Get maximum memory for Type 42 fonts

Returns:

  • (Integer, nil) —

    Maximum memory in bytes, or nil if not parsed



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# File 'lib/fontisan/tables/post_table.rb', line 84

def max_mem_type42
  parsed&.max_mem_type42
end

#min_mem_type1 ⇒ Integer?

Get minimum memory for Type 1 fonts

Returns:

  • (Integer, nil) —

    Minimum memory in bytes, or nil if not parsed



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# File 'lib/fontisan/tables/post_table.rb', line 91

def min_mem_type1
  parsed&.min_mem_type1
end

#min_mem_type42 ⇒ Integer?

Get minimum memory for Type 42 fonts

Returns:

  • (Integer, nil) —

    Minimum memory in bytes, or nil if not parsed



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# File 'lib/fontisan/tables/post_table.rb', line 77

def min_mem_type42
  parsed&.min_mem_type42
end

#named_glyph_count ⇒ Integer

Get the number of glyphs with names

Returns:

  • (Integer) —

    Number of named glyphs



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# File 'lib/fontisan/tables/post_table.rb', line 136

def named_glyph_count
  glyph_names.length
end

#underline_position ⇒ Integer?

Get underline position

Distance from baseline to top of underline (negative for under baseline)

Returns:

  • (Integer, nil) —

    Underline position in FUnits, or nil if not parsed



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# File 'lib/fontisan/tables/post_table.rb', line 54

def underline_position
  parsed&.underline_position
end

#underline_thickness ⇒ Integer?

Get underline thickness

Returns:

  • (Integer, nil) —

    Underline thickness in FUnits, or nil if not parsed



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# File 'lib/fontisan/tables/post_table.rb', line 61

def underline_thickness
  parsed&.underline_thickness
end

#version ⇒ Float?

Get post table version

Returns:

  • (Float, nil) —

    Version number (1.0, 2.0, 2.5, 3.0, or 4.0)



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# File 'lib/fontisan/tables/post_table.rb', line 24

def version
  return nil unless parsed

  parsed.version
end