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# coding: utf-8
# typed: strict
# frozen_string_literal: true
require 'ttfunk'
class PDF::Reader
# Font descriptors are outlined in Section 9.8, PDF 32000-1:2008, pp 281-288
class FontDescriptor
#: String
attr_reader :font_name
#: String?
attr_reader :font_family
#: Symbol
attr_reader :font_stretch
#: Numeric
attr_reader :font_weight
#: Array[Numeric]
attr_reader :font_bounding_box
#: Numeric
attr_reader :cap_height
#: Numeric
attr_reader :ascent
#: Numeric
attr_reader :descent
#: Numeric
attr_reader :leading
#: Numeric
attr_reader :avg_width
#: Numeric
attr_reader :max_width
#: Numeric
attr_reader :missing_width
#: Numeric?
attr_reader :italic_angle
#: Numeric?
attr_reader :stem_v
#: Numeric?
attr_reader :x_height
#: Integer
attr_reader :font_flags
#: (PDF::Reader::ObjectHash, Hash[untyped, untyped]) -> void
def initialize(ohash, fd_hash)
# TODO change these to typed derefs
@ascent = ohash.deref_number(fd_hash[:Ascent]) || 0 #: Numeric
@descent = ohash.deref_number(fd_hash[:Descent]) || 0 #: Numeric
@missing_width = ohash.deref_number(fd_hash[:MissingWidth]) || 0 #: Numeric
@font_bounding_box = ohash.deref_array_of_numbers(
fd_hash[:FontBBox]
) || [0,0,0,0] #: Array[Numeric]
@avg_width = ohash.deref_number(fd_hash[:AvgWidth]) || 0 #: Numeric
@cap_height = ohash.deref_number(fd_hash[:CapHeight]) || 0 #: Numeric
@font_flags = ohash.deref_integer(fd_hash[:Flags]) || 0 #: Integer
@italic_angle = ohash.deref_number(fd_hash[:ItalicAngle]) #: Numeric?
@font_name = ohash.deref_name(fd_hash[:FontName]).to_s #: String
@leading = ohash.deref_number(fd_hash[:Leading]) || 0 #: Numeric
@max_width = ohash.deref_number(fd_hash[:MaxWidth]) || 0 #: Numeric
@stem_v = ohash.deref_number(fd_hash[:StemV]) #: Numeric?
@x_height = ohash.deref_number(fd_hash[:XHeight]) #: Numeric?
@font_stretch = ohash.deref_name(fd_hash[:FontStretch]) || :Normal #: Symbol
@font_weight = ohash.deref_number(fd_hash[:FontWeight]) || 400 #: Numeric
@font_family = ohash.deref_string(fd_hash[:FontFamily]) #: String?
# A FontDescriptor may have an embedded font program in FontFile
# (Type 1 Font Program), FontFile2 (TrueType font program), or
# FontFile3 (Other font program as defined by Subtype entry)
# Subtype entries:
# 1) Type1C: Type 1 Font Program in Compact Font Format
# 2) CIDFontType0C: Type 0 Font Program in Compact Font Format
# 3) OpenType: OpenType Font Program
# see Section 9.9, PDF 32000-1:2008, pp 288-292
@font_program_stream = ohash.deref_stream(fd_hash[:FontFile2]) #: PDF::Reader::Stream?
#TODO handle FontFile and FontFile3
@ttf_program_stream = nil #: TTFunk::File?
@is_ttf = @font_program_stream ? true : false #: bool
@glyph_to_pdf_sf = nil #: Numeric?
end
#: (Integer) -> Numeric
def glyph_width(char_code)
if @is_ttf
if ttf_program_stream.cmap.unicode.length > 0
glyph_id = ttf_program_stream.cmap.unicode.first[char_code]
else
glyph_id = char_code
end
char_metric = ttf_program_stream.horizontal_metrics.metrics[glyph_id]
if char_metric
char_metric.advance_width
else
0
end
end
end
# PDF states that a glyph is 1000 units wide, true type doesn't enforce
# any behavior, but uses units/em to define how wide the 'M' is (the widest letter)
#: () -> Numeric
def glyph_to_pdf_scale_factor
if @is_ttf
@glyph_to_pdf_sf ||= (1.0 / ttf_program_stream.header.units_per_em) * 1000.0
else
@glyph_to_pdf_sf ||= 1.0
end
@glyph_to_pdf_sf
end
private
#: () -> TTFunk::File
def ttf_program_stream
raise MalformedPDFError, "No font_program_stream" unless @font_program_stream
@ttf_program_stream ||= TTFunk::File.new(@font_program_stream.unfiltered_data)
end
end
end
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