summaryrefslogtreecommitdiff
path: root/fonts/gentium-tug/source/type1/greekcorrection.py
blob: aebe686af466096128c3ccfaadffaa92a94df207 (plain)
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
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
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
#! /usr/bin/env python3
# This file is part of the Gentium package for TeX.
# It is licensed under the Expat License, see doc//README for details.
# author: Pavel Farar, pavel.farar@centrum.cz
#
# This script generates extra kerning pairs for the
# combination accent + capital Greek letter. The kerning
# pairs will have such a value that the combination will
# look like the precomposed accented letter (with the
# exception of the left side bearing). The input must be
# a fontforge source (sfd file) and the output will have
# the same form as kerning pairs in the afm file
#
# The main idea is that the fontforge source contains the
# information how the accented letter is composed from the
# accent and the base letter. The relevant information is
# the width of the accent and the position of the accent
# and the base letter (how they are moved from the position
# X = 0). The kerning is computed using the following formula:
#
# Kern = X_letter - X_accent - WidthOfAccent
#
# This script is dirtier than it could be. The
# reason is that it should work with different fonts,
# but some fonts have problems. There is a problem
# with the letter Omega in GentiumPlus which has not
# the usual unicode value. In DejaVu the precomposed
# letters are composed sometimes as accent + letter,
# but sometimes also as letter + accent.

import sys

# Table with LIGKERNs for Greek capital letters, where
# first (accent) + second (letter) gives third (accented
# letter.  Well, probably not the best term, but I created
# the following table to a great extent automatically
# from the LIGKERN commands for the precomposed small Greek
# accented letters in the encoding LGR. Then I did uppercasing
# using information from Unicode and looked if there is
# some accented letter missing. Therefore I call it
# LigatureTable and this file uses one line for every
# capital Greek letter. I did it in such a way to avoid
# random errors.
LigatureTable = []

LigatureTable.append(['uni1FBF', 'Alpha', 'uni1F08'])
LigatureTable.append(['uni1FBF', 'Epsilon', 'uni1F18'])
LigatureTable.append(['uni1FBF', 'Eta', 'uni1F28'])
LigatureTable.append(['uni1FBF', 'Iota', 'uni1F38'])
LigatureTable.append(['uni1FBF', 'Omicron', 'uni1F48'])
LigatureTable.append(['uni1FBF', 'Omega', 'uni1F68'])
LigatureTable.append(['uni1FFE', 'Alpha', 'uni1F09'])
LigatureTable.append(['uni1FFE', 'Epsilon', 'uni1F19'])
LigatureTable.append(['uni1FFE', 'Eta', 'uni1F29'])
LigatureTable.append(['uni1FFE', 'Iota', 'uni1F39'])
LigatureTable.append(['uni1FFE', 'Omicron', 'uni1F49'])
LigatureTable.append(['uni1FFE', 'Upsilon', 'uni1F59'])
LigatureTable.append(['uni1FFE', 'Omega', 'uni1F69'])
LigatureTable.append(['uni1FFE', 'Rho', 'uni1FEC'])
LigatureTable.append(['uni1FCD', 'Alpha', 'uni1F0A'])
LigatureTable.append(['uni1FCD', 'Epsilon', 'uni1F1A'])
LigatureTable.append(['uni1FCD', 'Eta', 'uni1F2A'])
LigatureTable.append(['uni1FCD', 'Iota', 'uni1F3A'])
LigatureTable.append(['uni1FCD', 'Omicron', 'uni1F4A'])
LigatureTable.append(['uni1FCD', 'Omega', 'uni1F6A'])
LigatureTable.append(['uni1FDD', 'Alpha', 'uni1F0B'])
LigatureTable.append(['uni1FDD', 'Epsilon', 'uni1F1B'])
LigatureTable.append(['uni1FDD', 'Eta', 'uni1F2B'])
LigatureTable.append(['uni1FDD', 'Iota', 'uni1F3B'])
LigatureTable.append(['uni1FDD', 'Omicron', 'uni1F4B'])
LigatureTable.append(['uni1FDD', 'Upsilon', 'uni1F5B'])
LigatureTable.append(['uni1FDD', 'Omega', 'uni1F6B'])
LigatureTable.append(['uni1FCE', 'Alpha', 'uni1F0C'])
LigatureTable.append(['uni1FCE', 'Epsilon', 'uni1F1C'])
LigatureTable.append(['uni1FCE', 'Eta', 'uni1F2C'])
LigatureTable.append(['uni1FCE', 'Iota', 'uni1F3C'])
LigatureTable.append(['uni1FCE', 'Omicron', 'uni1F4C'])
LigatureTable.append(['uni1FCE', 'Omega', 'uni1F6C'])
LigatureTable.append(['uni1FDE', 'Alpha', 'uni1F0D'])
LigatureTable.append(['uni1FDE', 'Epsilon', 'uni1F1D'])
LigatureTable.append(['uni1FDE', 'Eta', 'uni1F2D'])
LigatureTable.append(['uni1FDE', 'Iota', 'uni1F3D'])
LigatureTable.append(['uni1FDE', 'Omicron', 'uni1F4D'])
LigatureTable.append(['uni1FDE', 'Upsilon', 'uni1F5D'])
LigatureTable.append(['uni1FDE', 'Omega', 'uni1F6D'])
LigatureTable.append(['uni1FCF', 'Alpha', 'uni1F0E'])
LigatureTable.append(['uni1FCF', 'Eta', 'uni1F2E'])
LigatureTable.append(['uni1FCF', 'Iota', 'uni1F3E'])
LigatureTable.append(['uni1FCF', 'Omega', 'uni1F6E'])
LigatureTable.append(['uni1FDF', 'Alpha', 'uni1F0F'])
LigatureTable.append(['uni1FDF', 'Eta', 'uni1F2F'])
LigatureTable.append(['uni1FDF', 'Iota', 'uni1F3F'])
LigatureTable.append(['uni1FDF', 'Upsilon', 'uni1F5F'])
LigatureTable.append(['uni1FDF', 'Omega', 'uni1F6F'])
LigatureTable.append(['uni1FEF', 'Alpha', 'uni1FBA'])
LigatureTable.append(['uni1FEF', 'Epsilon', 'uni1FC8'])
LigatureTable.append(['uni1FEF', 'Eta', 'uni1FCA'])
LigatureTable.append(['uni1FEF', 'Iota', 'uni1FDA'])
LigatureTable.append(['uni1FEF', 'Omicron', 'uni1FF8'])
LigatureTable.append(['uni1FEF', 'Upsilon', 'uni1FEA'])
LigatureTable.append(['uni1FEF', 'Omega', 'uni1FFA'])
LigatureTable.append(['tonos', 'Alpha', 'Alphatonos'])
LigatureTable.append(['tonos', 'Epsilon', 'Epsilontonos'])
LigatureTable.append(['tonos', 'Eta', 'Etatonos'])
LigatureTable.append(['tonos', 'Iota', 'Iotatonos'])
LigatureTable.append(['tonos', 'Omicron', 'Omicrontonos'])
LigatureTable.append(['tonos', 'Upsilon', 'Upsilontonos'])
LigatureTable.append(['tonos', 'Omega', 'Omegatonos'])


# Set with Greek accents
GreekAccents = set()  # empty set
for i in range(len(LigatureTable)):
    GreekAccents.add(LigatureTable[i][0])

# Set with Greek letters
GreekLetters = set()  # empty set
for i in range(len(LigatureTable)):
    GreekLetters.add(LigatureTable[i][1])

# Set with precomposed Greek letters
PrecomposedGreekLetters = set()  # empty set
for i in range(len(LigatureTable)):
    PrecomposedGreekLetters.add(LigatureTable[i][2])


def UnicodeValue(s):
    # The unicode value is the second number after "Encoding:"
    if s.find('Encoding:') != 0:
        sys.exit('UnicodeValue error')
    return s.split()[2]  # The third item


def WidthValue(s):
    if s.find('Width:') != 0:
        sys.exit('WidthValue error')
    return s.split()[1]  # The second item


# Dictionaries (all values are strings, not numbers!)
AccentWidth = {}
AccentUnicode = {}
LetterUnicode = {}


# Process the components (accents and base letters)
f = open(sys.argv[1], 'r')
farray = f.readlines()
f.close()
findex = -1
while True:
    findex = findex + 1
    if findex >= len(farray):
        break  # end of file
    s = farray[findex]
    if s.find('StartChar: ') == 0:
        CharacterName = s[11:-1]
        if CharacterName in GreekLetters:
            findex = findex + 1
            s = farray[findex]
            LetterUnicode[CharacterName] = UnicodeValue(s)
        if CharacterName in GreekAccents:
            findex = findex + 1
            s = farray[findex]
            AccentUnicode[CharacterName] = UnicodeValue(s)
            findex = findex + 1
            s = farray[findex]
            AccentWidth[CharacterName] = WidthValue(s)


def MoveValue(ss, lindex):
    sarray = ss.split()
    if sarray[0] != 'Refer:':
        sys.exit('No Refer:')
    x = int(sarray[8])  # the value of move

    # dirty hack to make Omega work in both Gentium and GentiumPlus
    # This script without the following hack would work well for Gentium, but not for
    # GentiumPlus. The problem with GentiumPlus is that the accented letters with Omega
    # uses as a base letter that with the unicode value 937 (which should be Omega), but
    # this letter has PostScript name uni03A9, not Omega. Omega has a different value.
    if (
        sarray[2] == '937'
    ):  # the standard unicode value for Omega = problems in GentiumPlus
        sarray[2] = LetterUnicode['Omega']

    # is it accent or letter?
    # unicode is the second number (third value)
    if sarray[2] == AccentUnicode[LigatureTable[lindex][0]]:  # accent
        x = -x  # the move of accent is taken negatively
    elif sarray[2] == LetterUnicode[LigatureTable[lindex][1]]:  # letter
        x = +x  # the move of letter is taken positively
    else:
        sys.exit('Bad unicode of component')

    return x


def KernValue(letter, s1, s2):
    # letter	- the name of the precomposed letter
    # s1		- Refer to the accent (expected to be first)
    # s2		- Refer to the letter
    for i in range(len(LigatureTable)):
        if LigatureTable[i][2] == letter:
            LetterIndex = i

    FirstMove = MoveValue(s1, LetterIndex)
    SecondMove = MoveValue(s2, LetterIndex)

    return FirstMove + SecondMove - int(AccentWidth[LigatureTable[LetterIndex][0]])


KernTable = {}

# Process the precomposed letters
# The sfd file is still in "farray"
findex = -1
while True:
    findex = findex + 1
    if findex >= len(farray):
        break  # end of file
    s = farray[findex]
    if s.find('StartChar: ') == 0:
        CharacterName = s[11:-1]
        if CharacterName in PrecomposedGreekLetters:
            while s.find('Refer: ') != 0:
                findex = findex + 1
                s = farray[findex]
            KernTable[CharacterName] = KernValue(CharacterName, s, farray[findex + 1])


# Write the kerning table
fafm = open(sys.argv[1][:-4] + '-extra.afm', 'w')
for i in range(len(LigatureTable)):
    sourceKern = KernTable[LigatureTable[i][2]]
    if sourceKern != 0:  # remove zero kerns
        fafm.write(
            'KPX '
            + LigatureTable[i][0]
            + ' '
            + LigatureTable[i][1]
            + ' '
            + str(int(round(1000.0 / 2048.0 * sourceKern)))
            + '\n'
        )
fafm.close()