harfbuzz/src/hb-ot-shape-complex-myanmar.cc

546 lines
15 KiB
C++

/*
* Copyright © 2011,2012,2013 Google, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Google Author(s): Behdad Esfahbod
*/
#include "hb-ot-shape-complex-indic-private.hh"
/* buffer var allocations */
#define myanmar_category() complex_var_u8_0() /* myanmar_category_t */
#define myanmar_position() complex_var_u8_1() /* myanmar_position_t */
/*
* Myanmar shaper.
*/
static const hb_tag_t
basic_features[] =
{
/*
* Basic features.
* These features are applied in order, one at a time, after initial_reordering.
*/
HB_TAG('r','p','h','f'),
HB_TAG('p','r','e','f'),
HB_TAG('b','l','w','f'),
HB_TAG('p','s','t','f'),
};
static const hb_tag_t
other_features[] =
{
/*
* Other features.
* These features are applied all at once, after final_reordering.
*/
HB_TAG('p','r','e','s'),
HB_TAG('a','b','v','s'),
HB_TAG('b','l','w','s'),
HB_TAG('p','s','t','s'),
/* Positioning features, though we don't care about the types. */
HB_TAG('d','i','s','t'),
/* Pre-release version of Windows 8 Myanmar font had abvm,blwm
* features. The released Windows 8 version of the font (as well
* as the released spec) used 'mark' instead. The Windows 8
* shaper however didn't apply 'mark' but did apply 'mkmk'.
* Perhaps it applied abvm/blwm. This was fixed in a Windows 8
* update, so now it applies mark/mkmk. We are guessing that
* it still applies abvm/blwm too.
*/
HB_TAG('a','b','v','m'),
HB_TAG('b','l','w','m'),
};
static void
setup_syllables (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static void
initial_reordering (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static void
final_reordering (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static void
collect_features_myanmar (hb_ot_shape_planner_t *plan)
{
hb_ot_map_builder_t *map = &plan->map;
/* Do this before any lookups have been applied. */
map->add_gsub_pause (setup_syllables);
map->add_global_bool_feature (HB_TAG('l','o','c','l'));
/* The Indic specs do not require ccmp, but we apply it here since if
* there is a use of it, it's typically at the beginning. */
map->add_global_bool_feature (HB_TAG('c','c','m','p'));
map->add_gsub_pause (initial_reordering);
for (unsigned int i = 0; i < ARRAY_LENGTH (basic_features); i++)
{
map->add_feature (basic_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ);
map->add_gsub_pause (NULL);
}
map->add_gsub_pause (final_reordering);
for (unsigned int i = 0; i < ARRAY_LENGTH (other_features); i++)
map->add_feature (other_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ);
}
static void
override_features_myanmar (hb_ot_shape_planner_t *plan)
{
plan->map.add_feature (HB_TAG('l','i','g','a'), 0, F_GLOBAL);
}
enum syllable_type_t {
consonant_syllable,
punctuation_cluster,
broken_cluster,
non_myanmar_cluster,
};
#include "hb-ot-shape-complex-myanmar-machine.hh"
/* Note: This enum is duplicated in the -machine.rl source file.
* Not sure how to avoid duplication. */
enum myanmar_category_t {
OT_As = 18, /* Asat */
OT_D = 19, /* Digits except zero */
OT_D0 = 20, /* Digit zero */
OT_DB = OT_N, /* Dot below */
OT_GB = OT_PLACEHOLDER,
OT_MH = 21, /* Various consonant medial types */
OT_MR = 22, /* Various consonant medial types */
OT_MW = 23, /* Various consonant medial types */
OT_MY = 24, /* Various consonant medial types */
OT_PT = 25, /* Pwo and other tones */
OT_VAbv = 26,
OT_VBlw = 27,
OT_VPre = 28,
OT_VPst = 29,
OT_VS = 30, /* Variation selectors */
OT_P = 31 /* Punctuation */
};
static inline bool
is_one_of (const hb_glyph_info_t &info, unsigned int flags)
{
/* If it ligated, all bets are off. */
if (_hb_glyph_info_ligated (&info)) return false;
return !!(FLAG_SAFE (info.myanmar_category()) & flags);
}
static inline bool
is_consonant (const hb_glyph_info_t &info)
{
return is_one_of (info, CONSONANT_FLAGS);
}
static inline void
set_myanmar_properties (hb_glyph_info_t &info)
{
hb_codepoint_t u = info.codepoint;
unsigned int type = hb_indic_get_categories (u);
indic_category_t cat = (indic_category_t) (type & 0x7Fu);
indic_position_t pos = (indic_position_t) (type >> 8);
/* Myanmar
* http://www.microsoft.com/typography/OpenTypeDev/myanmar/intro.htm#analyze
*/
if (unlikely (hb_in_range (u, 0xFE00u, 0xFE0Fu)))
cat = (indic_category_t) OT_VS;
switch (u)
{
case 0x104Eu:
cat = (indic_category_t) OT_C; /* The spec says C, IndicSyllableCategory doesn't have. */
break;
case 0x002Du: case 0x00A0u: case 0x00D7u: case 0x2012u:
case 0x2013u: case 0x2014u: case 0x2015u: case 0x2022u:
case 0x25CCu: case 0x25FBu: case 0x25FCu: case 0x25FDu:
case 0x25FEu:
cat = (indic_category_t) OT_GB;
break;
case 0x1004u: case 0x101Bu: case 0x105Au:
cat = (indic_category_t) OT_Ra;
break;
case 0x1032u: case 0x1036u:
cat = (indic_category_t) OT_A;
break;
case 0x1039u:
cat = (indic_category_t) OT_H;
break;
case 0x103Au:
cat = (indic_category_t) OT_As;
break;
case 0x1041u: case 0x1042u: case 0x1043u: case 0x1044u:
case 0x1045u: case 0x1046u: case 0x1047u: case 0x1048u:
case 0x1049u: case 0x1090u: case 0x1091u: case 0x1092u:
case 0x1093u: case 0x1094u: case 0x1095u: case 0x1096u:
case 0x1097u: case 0x1098u: case 0x1099u:
cat = (indic_category_t) OT_D;
break;
case 0x1040u:
cat = (indic_category_t) OT_D; /* XXX The spec says D0, but Uniscribe doesn't seem to do. */
break;
case 0x103Eu: case 0x1060u:
cat = (indic_category_t) OT_MH;
break;
case 0x103Cu:
cat = (indic_category_t) OT_MR;
break;
case 0x103Du: case 0x1082u:
cat = (indic_category_t) OT_MW;
break;
case 0x103Bu: case 0x105Eu: case 0x105Fu:
cat = (indic_category_t) OT_MY;
break;
case 0x1063u: case 0x1064u: case 0x1069u: case 0x106Au:
case 0x106Bu: case 0x106Cu: case 0x106Du: case 0xAA7Bu:
cat = (indic_category_t) OT_PT;
break;
case 0x1038u: case 0x1087u: case 0x1088u: case 0x1089u:
case 0x108Au: case 0x108Bu: case 0x108Cu: case 0x108Du:
case 0x108Fu: case 0x109Au: case 0x109Bu: case 0x109Cu:
cat = (indic_category_t) OT_SM;
break;
case 0x104Au: case 0x104Bu:
cat = (indic_category_t) OT_P;
break;
case 0xAA74u: case 0xAA75u: case 0xAA76u:
/* https://github.com/roozbehp/unicode-data/issues/3 */
cat = (indic_category_t) OT_C;
break;
}
if (cat == OT_M)
{
switch ((int) pos)
{
case POS_PRE_C: cat = (indic_category_t) OT_VPre;
pos = POS_PRE_M; break;
case POS_ABOVE_C: cat = (indic_category_t) OT_VAbv; break;
case POS_BELOW_C: cat = (indic_category_t) OT_VBlw; break;
case POS_POST_C: cat = (indic_category_t) OT_VPst; break;
}
}
info.myanmar_category() = (myanmar_category_t) cat;
info.myanmar_position() = pos;
}
static void
setup_masks_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
hb_buffer_t *buffer,
hb_font_t *font HB_UNUSED)
{
HB_BUFFER_ALLOCATE_VAR (buffer, myanmar_category);
HB_BUFFER_ALLOCATE_VAR (buffer, myanmar_position);
/* We cannot setup masks here. We save information about characters
* and setup masks later on in a pause-callback. */
unsigned int count = buffer->len;
hb_glyph_info_t *info = buffer->info;
for (unsigned int i = 0; i < count; i++)
set_myanmar_properties (info[i]);
}
static void
setup_syllables (const hb_ot_shape_plan_t *plan HB_UNUSED,
hb_font_t *font HB_UNUSED,
hb_buffer_t *buffer)
{
find_syllables (buffer);
}
static int
compare_myanmar_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb)
{
int a = pa->myanmar_position();
int b = pb->myanmar_position();
return a < b ? -1 : a == b ? 0 : +1;
}
/* Rules from:
* http://www.microsoft.com/typography/OpenTypeDev/myanmar/intro.htm */
static void
initial_reordering_consonant_syllable (hb_buffer_t *buffer,
unsigned int start, unsigned int end)
{
hb_glyph_info_t *info = buffer->info;
unsigned int base = end;
bool has_reph = false;
{
unsigned int limit = start;
if (start + 3 <= end &&
info[start ].myanmar_category() == OT_Ra &&
info[start+1].myanmar_category() == OT_As &&
info[start+2].myanmar_category() == OT_H)
{
limit += 3;
base = start;
has_reph = true;
}
{
if (!has_reph)
base = limit;
for (unsigned int i = limit; i < end; i++)
if (is_consonant (info[i]))
{
base = i;
break;
}
}
}
/* Reorder! */
{
unsigned int i = start;
for (; i < start + (has_reph ? 3 : 0); i++)
info[i].myanmar_position() = POS_AFTER_MAIN;
for (; i < base; i++)
info[i].myanmar_position() = POS_PRE_C;
if (i < end)
{
info[i].myanmar_position() = POS_BASE_C;
i++;
}
indic_position_t pos = POS_AFTER_MAIN;
/* The following loop may be ugly, but it implements all of
* Myanmar reordering! */
for (; i < end; i++)
{
if (info[i].myanmar_category() == OT_MR) /* Pre-base reordering */
{
info[i].myanmar_position() = POS_PRE_C;
continue;
}
if (info[i].myanmar_position() < POS_BASE_C) /* Left matra */
{
continue;
}
if (pos == POS_AFTER_MAIN && info[i].myanmar_category() == OT_VBlw)
{
pos = POS_BELOW_C;
info[i].myanmar_position() = pos;
continue;
}
if (pos == POS_BELOW_C && info[i].myanmar_category() == OT_A)
{
info[i].myanmar_position() = POS_BEFORE_SUB;
continue;
}
if (pos == POS_BELOW_C && info[i].myanmar_category() == OT_VBlw)
{
info[i].myanmar_position() = pos;
continue;
}
if (pos == POS_BELOW_C && info[i].myanmar_category() != OT_A)
{
pos = POS_AFTER_SUB;
info[i].myanmar_position() = pos;
continue;
}
info[i].myanmar_position() = pos;
}
}
/* Sit tight, rock 'n roll! */
buffer->sort (start, end, compare_myanmar_order);
}
static void
initial_reordering_syllable (const hb_ot_shape_plan_t *plan,
hb_face_t *face,
hb_buffer_t *buffer,
unsigned int start, unsigned int end)
{
syllable_type_t syllable_type = (syllable_type_t) (buffer->info[start].syllable() & 0x0F);
switch (syllable_type) {
case broken_cluster: /* We already inserted dotted-circles, so just call the consonant_syllable. */
case consonant_syllable:
initial_reordering_consonant_syllable (buffer, start, end);
break;
case punctuation_cluster:
case non_myanmar_cluster:
break;
}
}
static inline void
insert_dotted_circles (const hb_ot_shape_plan_t *plan HB_UNUSED,
hb_font_t *font,
hb_buffer_t *buffer)
{
/* Note: This loop is extra overhead, but should not be measurable. */
bool has_broken_syllables = false;
unsigned int count = buffer->len;
hb_glyph_info_t *info = buffer->info;
for (unsigned int i = 0; i < count; i++)
if ((info[i].syllable() & 0x0F) == broken_cluster)
{
has_broken_syllables = true;
break;
}
if (likely (!has_broken_syllables))
return;
hb_codepoint_t dottedcircle_glyph;
if (!font->get_nominal_glyph (0x25CCu, &dottedcircle_glyph))
return;
hb_glyph_info_t dottedcircle = {0};
dottedcircle.codepoint = 0x25CCu;
set_myanmar_properties (dottedcircle);
dottedcircle.codepoint = dottedcircle_glyph;
buffer->clear_output ();
buffer->idx = 0;
unsigned int last_syllable = 0;
while (buffer->idx < buffer->len && !buffer->in_error)
{
unsigned int syllable = buffer->cur().syllable();
syllable_type_t syllable_type = (syllable_type_t) (syllable & 0x0F);
if (unlikely (last_syllable != syllable && syllable_type == broken_cluster))
{
last_syllable = syllable;
hb_glyph_info_t ginfo = dottedcircle;
ginfo.cluster = buffer->cur().cluster;
ginfo.mask = buffer->cur().mask;
ginfo.syllable() = buffer->cur().syllable();
buffer->output_info (ginfo);
}
else
buffer->next_glyph ();
}
buffer->swap_buffers ();
}
static void
initial_reordering (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer)
{
insert_dotted_circles (plan, font, buffer);
foreach_syllable (buffer, start, end)
initial_reordering_syllable (plan, font->face, buffer, start, end);
}
static void
final_reordering (const hb_ot_shape_plan_t *plan,
hb_font_t *font HB_UNUSED,
hb_buffer_t *buffer)
{
hb_glyph_info_t *info = buffer->info;
unsigned int count = buffer->len;
/* Zero syllables now... */
for (unsigned int i = 0; i < count; i++)
info[i].syllable() = 0;
HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_category);
HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_position);
}
/* Uniscribe seems to have a shaper for 'mymr' that is like the
* generic shaper, except that it zeros mark advances GDEF_LATE. */
const hb_ot_complex_shaper_t _hb_ot_complex_shaper_myanmar_old =
{
"default",
NULL, /* collect_features */
NULL, /* override_features */
NULL, /* data_create */
NULL, /* data_destroy */
NULL, /* preprocess_text */
NULL, /* postprocess_glyphs */
HB_OT_SHAPE_NORMALIZATION_MODE_DEFAULT,
NULL, /* decompose */
NULL, /* compose */
NULL, /* setup_masks */
NULL, /* disable_otl */
HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE,
true, /* fallback_position */
};
const hb_ot_complex_shaper_t _hb_ot_complex_shaper_myanmar =
{
"myanmar",
collect_features_myanmar,
override_features_myanmar,
NULL, /* data_create */
NULL, /* data_destroy */
NULL, /* preprocess_text */
NULL, /* postprocess_glyphs */
HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
NULL, /* decompose */
NULL, /* compose */
setup_masks_myanmar,
NULL, /* disable_otl */
HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
false, /* fallback_position */
};