1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
# frozen_string_literal: true
require_relative '../../reader'
module TTFunk
class Table
class Cmap
# Character to Glyph Index encoding record.
# This class can be extended with a format-specific
#
# @see TTFunk::Table::Cmap::Format00
# @see TTFunk::Table::Cmap::Format04
# @see TTFunk::Table::Cmap::Format06
# @see TTFunk::Table::Cmap::Format10
# @see TTFunk::Table::Cmap::Format12
class Subtable
include Reader
# Platform ID.
# @return [Integer]
attr_reader :platform_id
# Platform-specific encoding ID.
# @return [Integere]
attr_reader :encoding_id
# Record encoding format.
# @return [Integer]
attr_reader :format
# Most used encoding mappings.
ENCODING_MAPPINGS = {
mac_roman: { platform_id: 1, encoding_id: 0 }.freeze,
# Use microsoft unicode, instead of generic unicode, for optimal
# Windows support
unicode: { platform_id: 3, encoding_id: 1 }.freeze,
unicode_ucs4: { platform_id: 3, encoding_id: 10 }.freeze,
}.freeze
# Encode encoding record.
#
# @param charmap [Hash{Integer => Integer}] keys are code points in the
# used encoding, values are Unicode code points.
# @param encoding [Symbol] - one of the encodign mapping in
# {ENCODING_MAPPINGS}
# @return [Hash]
# * `:platform_id` (<tt>Integer</tt>) - Platform ID of this encoding record.
# * `:encoding_id` (<tt>Integer</tt>) - Encodign ID of this encoding record.
# * `:subtable` (<tt>String</tt>) - encoded encoding record.
# * `:max_glyph_id` (<tt>Integer</tt>) - maximum glyph ID in this encoding
# record.
# * `:charmap` (<tt>Hash{Integer => Hash}</tt>) - keys are codepoints in this
# encoding record, values are hashes:
# * `:new` - new glyph ID.
# * `:old` - glyph ID in the original font.
def self.encode(charmap, encoding)
case encoding
when :mac_roman
result = Format00.encode(charmap)
when :unicode
result = Format04.encode(charmap)
when :unicode_ucs4
result = Format12.encode(charmap)
else
raise NotImplementedError,
"encoding #{encoding.inspect} is not supported"
end
mapping = ENCODING_MAPPINGS[encoding]
# platform-id, encoding-id, offset
result.merge(
platform_id: mapping[:platform_id],
encoding_id: mapping[:encoding_id],
subtable: [
mapping[:platform_id],
mapping[:encoding_id],
12,
result[:subtable],
].pack('nnNA*'),
)
end
# @param file [TTFunk::File]
# @param table_start [Integer]
def initialize(file, table_start)
@file = file
@platform_id, @encoding_id, @offset = read(8, 'nnN')
@offset += table_start
parse_from(@offset) do
@format = read(2, 'n').first
case @format
when 0 then extend(TTFunk::Table::Cmap::Format00)
when 4 then extend(TTFunk::Table::Cmap::Format04)
when 6 then extend(TTFunk::Table::Cmap::Format06)
when 10 then extend(TTFunk::Table::Cmap::Format10)
when 12 then extend(TTFunk::Table::Cmap::Format12)
end
parse_cmap!
end
end
# Is this an encoding record for Unicode?
#
# @return [Boolean]
def unicode?
(platform_id == 3 && (encoding_id == 1 || encoding_id == 10) && format != 0) ||
(platform_id.zero? && format != 0)
end
# Is this encoding record format supported?
#
# @return [Boolean]
def supported?
false
end
# Get glyph ID for character code.
#
# @param _code [Integer] character code.
# @return [Integer] glyph ID.
def [](_code)
raise NotImplementedError, "cmap format #{@format} is not supported"
end
private
def parse_cmap!
# do nothing...
end
end
end
end
end
require_relative 'format00'
require_relative 'format04'
require_relative 'format06'
require_relative 'format10'
require_relative 'format12'
|
