Class: Text2svg::Typography

Inherits:
Object
  • Object
show all
Defined in:
lib/text2svg/typography.rb

Constant Summary collapse

WHITESPACE =
/[[:space:]]/
IDEOGRAPHIC_SPACE =
/[\u{3000}]/
NEW_LINE =
/[\u{000A}]/
NOTDEF_GLYPH_ID =
0

Class Method Summary collapse

Class Method Details

.build(text, option) ⇒ Object



17
18
19
20
21
22
23
24
25
26
27
# File 'lib/text2svg/typography.rb', line 17

def build(text, option)
  if Hash === option
    option = Option.from_hash(option)
  end
  content = path(text, option)
  svg = %(<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 #{content.width} #{content.height}">\n)
  svg << "<title>#{CGI.escapeHTML(text.to_s)}</title>\n"
  svg << content.data
  svg << "</svg>\n"
  Content.new(svg, content.width, content.height, content.notdef_indexes)
end

.path(text, option) ⇒ Object



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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
# File 'lib/text2svg/typography.rb', line 29

def path(text, option)
  if Hash === option
    option = Option.from_hash(option)
  end
  text = String.try_convert(text)
  return Content.new('', 0, 0, []) if text.nil? || text.empty?

  option.encoding ||= Encoding::UTF_8
  option.text_align ||= :left
  text.force_encoding(option.encoding).encode!(Encoding::UTF_8)

  notdef_indexes = []
  unless option.font
    raise OptionError, 'should set `font\' option'
  end
  char_sizes = option.char_size.split(',').map(&:to_i)
  unless char_sizes.length == 4
    raise OptionError, 'char-size option should be four integer values'
  end
  FreeType::API::Font.open(File.expand_path(option.font)) do |f|
    f.set_char_size(*char_sizes)

    lines = []
    line = []
    lines << line
     = [0]

    space_width = f.glyph(' '.freeze).char_width
    text.each_char.with_index do |char, index|
      if NEW_LINE.match char
        [-1] = min_hori_bearing_x(line)
         << 0
        line = []
        lines << line
        next
      end

      glyph_id = f.char_index(char)
      glyph = if glyph_id == 0
        notdef_indexes << index
        f.notdef
      else
        f.glyph(char)
      end

      if glyph.outline.tags.empty?
        notdef_indexes << index
        glyph = f.notdef
      end

      glyph.bold if option.bold
      glyph.italic if option.italic

      metrics = FreeType::C::FT_Glyph_Metrics.new
      is_draw = if IDEOGRAPHIC_SPACE.match char
        metrics[:width] = space_width * 2r
        metrics[:height] = 0
        metrics[:horiBearingX] = space_width * 2r
        metrics[:horiBearingY] = 0
        metrics[:horiAdvance] = space_width * 2r
        metrics[:vertBearingX] = 0
        metrics[:vertBearingY] = 0
        metrics[:vertAdvance] = 0

        false
      elsif WHITESPACE.match char
        metrics[:width] = space_width
        metrics[:height] = 0
        metrics[:horiBearingX] = space_width
        metrics[:horiBearingY] = 0
        metrics[:horiAdvance] = space_width
        metrics[:vertBearingX] = 0
        metrics[:vertBearingY] = 0
        metrics[:vertAdvance] = 0

        false
      else
        FreeType::C::FT_Glyph_Metrics.members.each do |m|
          metrics[m] = glyph.metrics[m]
        end

        true
      end
      line << CharSet.new(char, metrics, is_draw, glyph.outline.svg_path_data)
    end

    [-1] = min_hori_bearing_x(line)
    inter_char_space = space_width / INTER_CHAR_SPACE_DIV
    min_hori_bearing_x_all = .min

     = lines.map do |line|
      before_char = nil
      if line.empty?.!
        line.map { |cs|
          width = if cs.equal?(line.last)
            cs.metrics[:width] + cs.metrics[:horiBearingX]
          else
            cs.metrics[:horiAdvance]
          end
          w = width + f.kerning_unfitted(before_char, cs.char).x
          w.tap { before_char = cs.char }
        }.inject(:+) + (line.length - 1) * inter_char_space - min_hori_bearing_x_all
      else
        0
      end
    end
    max_width = .max

    y = 0r
    output = ''
    output << %(<g #{option.attribute}>\n) if option.attribute

    lines.zip().each_with_index do |(line, line_width), index|
      x = 0r
      y += if index == 0
        f.face[:size][:metrics][:ascender] * option.scale
      else
        f.line_height * option.scale
      end
      before_char = nil

      case option.text_align.to_sym
      when :center
        x += (max_width - line_width) / 2r * option.scale
      when :right
        x += (max_width - line_width) * option.scale
      when :left
        # nothing
      else
        warn 'text_align must be left,right or center'
      end

      output << %!<g transform="matrix(1,0,0,1,0,#{y.round})">\n!

      x -= min_hori_bearing_x_all * option.scale
      sr = option.scale.rationalize
      line.each do |cs|
        x += f.kerning_unfitted(before_char, cs.char).x * option.scale
        if cs.draw?
          d = cs.outline2d.map do |cmd, *points|
            [
              cmd,
              *points.map { |i|
                i.rationalize * sr
              }.map do |i|
                i.denominator == 1 ? i.to_i : i.to_f
              end,
            ]
          end
          output << %!  <path transform="matrix(1,0,0,1,#{x.round},0)" d="#{d.join(' '.freeze)}"/>\n!
        end
        x += cs.metrics[:horiAdvance] * option.scale
        x += inter_char_space * option.scale if cs != line.last
        before_char = cs.char
      end
      output << "</g>\n".freeze
    end
    output << "</g>\n".freeze if option.attribute

    option_width = 0
    option_width += (space_width / 1.5 * option.scale) if option.italic
    Content.new(
      output,
      ((max_width + option_width) * option.scale).ceil,
      (y - f.face[:size][:metrics][:descender] * 1.2 * option.scale).ceil,
      notdef_indexes,
    )
  end
end