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

551 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 (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 & 0x7F);
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<hb_codepoint_t> (u, 0xFE00, 0xFE0F)))
cat = (indic_category_t) OT_VS;
switch (u)
{
case 0x104E:
cat = (indic_category_t) OT_C; /* The spec says C, IndicSyllableCategory doesn't have. */
break;
case 0x002D: case 0x00A0: case 0x00D7: case 0x2012:
case 0x2013: case 0x2014: case 0x2015: case 0x2022:
case 0x25CC: case 0x25FB: case 0x25FC: case 0x25FD:
case 0x25FE:
cat = (indic_category_t) OT_GB;
break;
case 0x1004: case 0x101B: case 0x105A:
cat = (indic_category_t) OT_Ra;
break;
case 0x1032: case 0x1036:
cat = (indic_category_t) OT_A;
break;
case 0x103A:
cat = (indic_category_t) OT_As;
break;
case 0x1041: case 0x1042: case 0x1043: case 0x1044:
case 0x1045: case 0x1046: case 0x1047: case 0x1048:
case 0x1049: case 0x1090: case 0x1091: case 0x1092:
case 0x1093: case 0x1094: case 0x1095: case 0x1096:
case 0x1097: case 0x1098: case 0x1099:
cat = (indic_category_t) OT_D;
break;
case 0x1040:
cat = (indic_category_t) OT_D; /* XXX The spec says D0, but Uniscribe doesn't seem to do. */
break;
case 0x103E: case 0x1060:
cat = (indic_category_t) OT_MH;
break;
case 0x103C:
cat = (indic_category_t) OT_MR;
break;
case 0x103D: case 0x1082:
cat = (indic_category_t) OT_MW;
break;
case 0x103B: case 0x105E: case 0x105F:
cat = (indic_category_t) OT_MY;
break;
case 0x1063: case 0x1064: case 0x1069: case 0x106A:
case 0x106B: case 0x106C: case 0x106D: case 0xAA7B:
cat = (indic_category_t) OT_PT;
break;
case 0x1038: case 0x1087: case 0x1088: case 0x1089:
case 0x108A: case 0x108B: case 0x108C: case 0x108D:
case 0x108F: case 0x109A: case 0x109B: case 0x109C:
cat = (indic_category_t) OT_SM;
break;
case 0x104A: case 0x104B:
cat = (indic_category_t) OT_P;
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;
for (unsigned int i = 0; i < count; i++)
set_myanmar_properties (buffer->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 (const hb_ot_shape_plan_t *plan,
hb_face_t *face,
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;
}
}
buffer->merge_clusters (start, end);
/* Sit tight, rock 'n roll! */
hb_bubble_sort (info + start, end - start, compare_myanmar_order);
}
static void
initial_reordering_broken_cluster (const hb_ot_shape_plan_t *plan,
hb_face_t *face,
hb_buffer_t *buffer,
unsigned int start, unsigned int end)
{
/* We already inserted dotted-circles, so just call the consonant_syllable. */
initial_reordering_consonant_syllable (plan, face, buffer, start, end);
}
static void
initial_reordering_punctuation_cluster (const hb_ot_shape_plan_t *plan HB_UNUSED,
hb_face_t *face HB_UNUSED,
hb_buffer_t *buffer HB_UNUSED,
unsigned int start HB_UNUSED, unsigned int end HB_UNUSED)
{
/* Nothing to do right now. If we ever switch to using the output
* buffer in the reordering process, we'd need to next_glyph() here. */
}
static void
initial_reordering_non_myanmar_cluster (const hb_ot_shape_plan_t *plan HB_UNUSED,
hb_face_t *face HB_UNUSED,
hb_buffer_t *buffer HB_UNUSED,
unsigned int start HB_UNUSED, unsigned int end HB_UNUSED)
{
/* Nothing to do right now. If we ever switch to using the output
* buffer in the reordering process, we'd need to next_glyph() here. */
}
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 consonant_syllable: initial_reordering_consonant_syllable (plan, face, buffer, start, end); return;
case punctuation_cluster: initial_reordering_punctuation_cluster (plan, face, buffer, start, end); return;
case broken_cluster: initial_reordering_broken_cluster (plan, face, buffer, start, end); return;
case non_myanmar_cluster: initial_reordering_non_myanmar_cluster (plan, face, buffer, start, end); return;
}
}
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;
for (unsigned int i = 0; i < count; i++)
if ((buffer->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_glyph (0x25CC, 0, &dottedcircle_glyph))
return;
hb_glyph_info_t dottedcircle = {0};
dottedcircle.codepoint = 0x25CC;
set_myanmar_properties (dottedcircle);
dottedcircle.codepoint = dottedcircle_glyph;
buffer->clear_output ();
buffer->idx = 0;
unsigned int last_syllable = 0;
while (buffer->idx < buffer->len)
{
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 info = dottedcircle;
info.cluster = buffer->cur().cluster;
info.mask = buffer->cur().mask;
info.syllable() = buffer->cur().syllable();
buffer->output_info (info);
}
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);
hb_glyph_info_t *info = buffer->info;
unsigned int count = buffer->len;
if (unlikely (!count)) return;
unsigned int last = 0;
unsigned int last_syllable = info[0].syllable();
for (unsigned int i = 1; i < count; i++)
if (last_syllable != info[i].syllable()) {
initial_reordering_syllable (plan, font->face, buffer, last, i);
last = i;
last_syllable = info[last].syllable();
}
initial_reordering_syllable (plan, font->face, buffer, last, count);
}
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);
}
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 */
HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
NULL, /* decompose */
NULL, /* compose */
setup_masks_myanmar,
HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
false, /* fallback_position */
};