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
|
#!/usr/bin/env python3
"""Generator of the function to prohibit certain vowel sequences.
It creates ``_hb_preprocess_text_vowel_constraints``, which inserts dotted
circles into sequences prohibited by the USE script development spec.
This function should be used as the ``preprocess_text`` of an
``hb_ot_complex_shaper_t``.
usage: ./gen-vowel-constraints.py ms-use/IndicShapingInvalidCluster.txt Scripts.txt
Input file:
* https://unicode.org/Public/UCD/latest/ucd/Scripts.txt
"""
import collections
def write (s):
sys.stdout.flush ()
sys.stdout.buffer.write (s.encode ('utf-8'))
import sys
if len (sys.argv) != 3:
sys.exit (__doc__)
with open (sys.argv[2], encoding='utf-8') as f:
scripts_header = [f.readline () for i in range (2)]
scripts = {}
script_order = {}
for line in f:
j = line.find ('#')
if j >= 0:
line = line[:j]
fields = [x.strip () for x in line.split (';')]
if len (fields) == 1:
continue
uu = fields[0].split ('..')
start = int (uu[0], 16)
if len (uu) == 1:
end = start
else:
end = int (uu[1], 16)
script = fields[1]
for u in range (start, end + 1):
scripts[u] = script
if script not in script_order:
script_order[script] = start
class ConstraintSet (object):
"""A set of prohibited code point sequences.
Args:
constraint (List[int]): A prohibited code point sequence.
"""
def __init__ (self, constraint):
# Either a list or a dictionary. As a list of code points, it
# represents a prohibited code point sequence. As a dictionary,
# it represents a set of prohibited sequences, where each item
# represents the set of prohibited sequences starting with the
# key (a code point) concatenated with any of the values
# (ConstraintSets).
self._c = constraint
def add (self, constraint):
"""Add a constraint to this set."""
if not constraint:
return
first = constraint[0]
rest = constraint[1:]
if isinstance (self._c, list):
if constraint == self._c[:len (constraint)]:
self._c = constraint
elif self._c != constraint[:len (self._c)]:
self._c = {self._c[0]: ConstraintSet (self._c[1:])}
if isinstance (self._c, dict):
if first in self._c:
self._c[first].add (rest)
else:
self._c[first] = ConstraintSet (rest)
@staticmethod
def _indent (depth):
return (' ' * depth).replace (' ', '\t')
def __str__ (self, index=0, depth=4):
s = []
indent = self._indent (depth)
if isinstance (self._c, list):
if len (self._c) == 0:
assert index == 2, 'Cannot use `matched` for this constraint; the general case has not been implemented'
s.append ('{}matched = true;\n'.format (indent))
elif len (self._c) == 1:
assert index == 1, 'Cannot use `matched` for this constraint; the general case has not been implemented'
s.append ('{}matched = 0x{:04X}u == buffer->cur ({}).codepoint;\n'.format (indent, next (iter (self._c)), index or ''))
else:
s.append ('{}if (0x{:04X}u == buffer->cur ({}).codepoint &&\n'.format (indent, self._c[0], index or ''))
if index:
s.append ('{}buffer->idx + {} < count &&\n'.format (self._indent (depth + 2), index + 1))
for i, cp in enumerate (self._c[1:], start=1):
s.append ('{}0x{:04X}u == buffer->cur ({}).codepoint{}\n'.format (
self._indent (depth + 2), cp, index + i, ')' if i == len (self._c) - 1 else ' &&'))
s.append ('{}{{\n'.format (indent))
for i in range (index):
s.append ('{}buffer->next_glyph ();\n'.format (self._indent (depth + 1)))
s.append ('{}matched = true;\n'.format (self._indent (depth + 1)))
s.append ('{}}}\n'.format (indent))
else:
s.append ('{}switch (buffer->cur ({}).codepoint)\n'.format(indent, index or ''))
s.append ('{}{{\n'.format (indent))
cases = collections.defaultdict (set)
for first, rest in sorted (self._c.items ()):
cases[rest.__str__ (index + 1, depth + 2)].add (first)
for body, labels in sorted (cases.items (), key=lambda b_ls: sorted (b_ls[1])[0]):
for i, cp in enumerate (sorted (labels)):
if i % 4 == 0:
s.append (self._indent (depth + 1))
else:
s.append (' ')
s.append ('case 0x{:04X}u:{}'.format (cp, '\n' if i % 4 == 3 else ''))
if len (labels) % 4 != 0:
s.append ('\n')
s.append (body)
s.append ('{}break;\n'.format (self._indent (depth + 2)))
s.append ('{}}}\n'.format (indent))
return ''.join (s)
constraints = {}
with open (sys.argv[1], encoding='utf-8') as f:
constraints_header = []
while True:
line = f.readline ().strip ()
if line == '#':
break
constraints_header.append(line)
for line in f:
j = line.find ('#')
if j >= 0:
line = line[:j]
constraint = [int (cp, 16) for cp in line.split (';')[0].split ()]
if not constraint: continue
assert 2 <= len (constraint), 'Prohibited sequence is too short: {}'.format (constraint)
script = scripts[constraint[0]]
if script in constraints:
constraints[script].add (constraint)
else:
constraints[script] = ConstraintSet (constraint)
assert constraints, 'No constraints found'
print ('/* == Start of generated functions == */')
print ('/*')
print (' * The following functions are generated by running:')
print (' *')
print (' * %s ms-use/IndicShapingInvalidCluster.txt Scripts.txt' % sys.argv[0])
print (' *')
print (' * on files with these headers:')
print (' *')
for line in constraints_header:
print (' * %s' % line.strip ())
print (' *')
for line in scripts_header:
print (' * %s' % line.strip ())
print (' */')
print ()
print ('#include "hb.hh"')
print ()
print ('#ifndef HB_NO_OT_SHAPE')
print ()
print ('#include "hb-ot-shape-complex-vowel-constraints.hh"')
print ()
print ('static void')
print ('_output_dotted_circle (hb_buffer_t *buffer)')
print ('{')
print (' hb_glyph_info_t &dottedcircle = buffer->output_glyph (0x25CCu);')
print (' _hb_glyph_info_reset_continuation (&dottedcircle);')
print ('}')
print ()
print ('static void')
print ('_output_with_dotted_circle (hb_buffer_t *buffer)')
print ('{')
print (' _output_dotted_circle (buffer);')
print (' buffer->next_glyph ();')
print ('}')
print ()
print ('void')
print ('_hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,')
print ('\t\t\t\t hb_buffer_t *buffer,')
print ('\t\t\t\t hb_font_t *font HB_UNUSED)')
print ('{')
print ('#ifdef HB_NO_OT_SHAPE_COMPLEX_VOWEL_CONSTRAINTS')
print (' return;')
print ('#endif')
print (' if (buffer->flags & HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE)')
print (' return;')
print ()
print (' /* UGLY UGLY UGLY business of adding dotted-circle in the middle of')
print (' * vowel-sequences that look like another vowel. Data for each script')
print (' * collected from the USE script development spec.')
print (' *')
print (' * https://github.com/harfbuzz/harfbuzz/issues/1019')
print (' */')
print (' bool processed = false;')
print (' buffer->clear_output ();')
print (' unsigned int count = buffer->len;')
print (' switch ((unsigned) buffer->props.script)')
print (' {')
for script, constraints in sorted (constraints.items (), key=lambda s_c: script_order[s_c[0]]):
print (' case HB_SCRIPT_{}:'.format (script.upper ()))
print (' for (buffer->idx = 0; buffer->idx + 1 < count && buffer->successful;)')
print (' {')
print ('\tbool matched = false;')
write (str (constraints))
print ('\tbuffer->next_glyph ();')
print ('\tif (matched) _output_with_dotted_circle (buffer);')
print (' }')
print (' processed = true;')
print (' break;')
print ()
print (' default:')
print (' break;')
print (' }')
print (' if (processed)')
print (' {')
print (' if (buffer->idx < count)')
print (' buffer->next_glyph ();')
print (' buffer->swap_buffers ();')
print (' }')
print ('}')
print ()
print ()
print ('#endif')
print ('/* == End of generated functions == */')
|
