diff options
Diffstat (limited to 'gfx/harfbuzz/src/gen-vowel-constraints.py')
| -rwxr-xr-x | gfx/harfbuzz/src/gen-vowel-constraints.py | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/gen-vowel-constraints.py b/gfx/harfbuzz/src/gen-vowel-constraints.py new file mode 100755 index 0000000000..3c1f6211eb --- /dev/null +++ b/gfx/harfbuzz/src/gen-vowel-constraints.py @@ -0,0 +1,229 @@ +#!/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_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 ('{}(void) 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-shaper-vowel-constraints.hh"') +print () +print ('static void') +print ('_output_dotted_circle (hb_buffer_t *buffer)') +print ('{') +print (' (void) buffer->output_glyph (0x25CCu);') +print (' _hb_glyph_info_reset_continuation (&buffer->prev());') +print ('}') +print () +print ('static void') +print ('_output_with_dotted_circle (hb_buffer_t *buffer)') +print ('{') +print (' _output_dotted_circle (buffer);') +print (' (void) 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_SHAPER_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 (' 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 ('\t(void) buffer->next_glyph ();') + print ('\tif (matched) _output_with_dotted_circle (buffer);') + print (' }') + print (' break;') + print () + +print (' default:') +print (' break;') +print (' }') +print (' buffer->sync ();') +print ('}') + +print () +print () +print ('#endif') +print ('/* == End of generated functions == */') |