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/*
* 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.hh"
#ifndef HB_NO_OT_SHAPE
#include "hb-ot-shaper-myanmar-machine.hh"
#include "hb-ot-shaper-indic.hh"
#include "hb-ot-layout.hh"
/*
* Myanmar shaper.
*/
static const hb_tag_t
myanmar_basic_features[] =
{
/*
* Basic features.
* These features are applied in order, one at a time, after reordering,
* constrained to the syllable.
*/
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
myanmar_other_features[] =
{
/*
* Other features.
* These features are applied all at once, after clearing syllables.
*/
HB_TAG('p','r','e','s'),
HB_TAG('a','b','v','s'),
HB_TAG('b','l','w','s'),
HB_TAG('p','s','t','s'),
};
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);
info.myanmar_category() = (myanmar_category_t) (type & 0xFFu);
}
static inline bool
is_one_of_myanmar (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_UNSAFE (info.myanmar_category()) & flags);
}
/* Note:
*
* We treat Vowels and placeholders as if they were consonants. This is safe because Vowels
* cannot happen in a consonant syllable. The plus side however is, we can call the
* consonant syllable logic from the vowel syllable function and get it all right!
*
* Keep in sync with consonant_categories in the generator. */
#define CONSONANT_FLAGS_MYANMAR (FLAG (M_Cat(C)) | FLAG (M_Cat(CS)) | FLAG (M_Cat(Ra)) | /* FLAG (M_Cat(CM)) | */ FLAG (M_Cat(IV)) | FLAG (M_Cat(GB)) | FLAG (M_Cat(DOTTEDCIRCLE)))
static inline bool
is_consonant_myanmar (const hb_glyph_info_t &info)
{
return is_one_of_myanmar (info, CONSONANT_FLAGS_MYANMAR);
}
static bool
setup_syllables_myanmar (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static bool
reorder_myanmar (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_myanmar);
map->enable_feature (HB_TAG('l','o','c','l'), F_PER_SYLLABLE);
/* 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->enable_feature (HB_TAG('c','c','m','p'), F_PER_SYLLABLE);
map->add_gsub_pause (reorder_myanmar);
for (unsigned int i = 0; i < ARRAY_LENGTH (myanmar_basic_features); i++)
{
map->enable_feature (myanmar_basic_features[i], F_MANUAL_ZWJ | F_PER_SYLLABLE);
map->add_gsub_pause (nullptr);
}
map->add_gsub_pause (hb_syllabic_clear_var); // Don't need syllables anymore, use stop to free buffer var
for (unsigned int i = 0; i < ARRAY_LENGTH (myanmar_other_features); i++)
map->enable_feature (myanmar_other_features[i], F_MANUAL_ZWJ);
}
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);
/* No masks, we just save information about characters. */
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 bool
setup_syllables_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
hb_font_t *font HB_UNUSED,
hb_buffer_t *buffer)
{
HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
find_syllables_myanmar (buffer);
foreach_syllable (buffer, start, end)
buffer->unsafe_to_break (start, end);
return false;
}
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 (int) a - (int) b;
}
/* Rules from:
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() == M_Cat(Ra) &&
info[start+1].myanmar_category() == M_Cat(As) &&
info[start+2].myanmar_category() == M_Cat(H))
{
limit += 3;
base = start;
has_reph = true;
}
{
if (!has_reph)
base = limit;
for (unsigned int i = limit; i < end; i++)
if (is_consonant_myanmar (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++;
}
myanmar_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() == M_Cat(MR)) /* Pre-base reordering */
{
info[i].myanmar_position() = POS_PRE_C;
continue;
}
if (info[i].myanmar_category() == M_Cat(VPre)) /* Left matra */
{
info[i].myanmar_position() = POS_PRE_M;
continue;
}
if (info[i].myanmar_category() == M_Cat(VS))
{
info[i].myanmar_position() = info[i - 1].myanmar_position();
continue;
}
if (pos == POS_AFTER_MAIN && info[i].myanmar_category() == M_Cat(VBlw))
{
pos = POS_BELOW_C;
info[i].myanmar_position() = pos;
continue;
}
if (pos == POS_BELOW_C && info[i].myanmar_category() == M_Cat(A))
{
info[i].myanmar_position() = POS_BEFORE_SUB;
continue;
}
if (pos == POS_BELOW_C && info[i].myanmar_category() == M_Cat(VBlw))
{
info[i].myanmar_position() = pos;
continue;
}
if (pos == POS_BELOW_C && info[i].myanmar_category() != M_Cat(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);
/* Flip left-matra sequence. */
unsigned first_left_matra = end;
unsigned last_left_matra = end;
for (unsigned int i = start; i < end; i++)
{
if (info[i].myanmar_position() == POS_PRE_M)
{
if (first_left_matra == end)
first_left_matra = i;
last_left_matra = i;
}
}
if (first_left_matra < last_left_matra)
{
/* No need to merge clusters, done already? */
buffer->reverse_range (first_left_matra, last_left_matra + 1);
/* Reverse back VS, etc. */
unsigned i = first_left_matra;
for (unsigned j = i; j <= last_left_matra; j++)
if (info[j].myanmar_category() == M_Cat(VPre))
{
buffer->reverse_range (i, j + 1);
i = j + 1;
}
}
}
static void
reorder_syllable_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
hb_face_t *face HB_UNUSED,
hb_buffer_t *buffer,
unsigned int start, unsigned int end)
{
myanmar_syllable_type_t syllable_type = (myanmar_syllable_type_t) (buffer->info[start].syllable() & 0x0F);
switch (syllable_type) {
case myanmar_broken_cluster: /* We already inserted dotted-circles, so just call the consonant_syllable. */
case myanmar_consonant_syllable:
initial_reordering_consonant_syllable (buffer, start, end);
break;
case myanmar_non_myanmar_cluster:
break;
}
}
static bool
reorder_myanmar (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer)
{
bool ret = false;
if (buffer->message (font, "start reordering myanmar"))
{
if (hb_syllabic_insert_dotted_circles (font, buffer,
myanmar_broken_cluster,
M_Cat(DOTTEDCIRCLE)))
ret = true;
foreach_syllable (buffer, start, end)
reorder_syllable_myanmar (plan, font->face, buffer, start, end);
(void) buffer->message (font, "end reordering myanmar");
}
HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_category);
HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_position);
return ret;
}
const hb_ot_shaper_t _hb_ot_shaper_myanmar =
{
collect_features_myanmar,
nullptr, /* override_features */
nullptr, /* data_create */
nullptr, /* data_destroy */
nullptr, /* preprocess_text */
nullptr, /* postprocess_glyphs */
nullptr, /* decompose */
nullptr, /* compose */
setup_masks_myanmar,
nullptr, /* reorder_marks */
HB_TAG_NONE, /* gpos_tag */
HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
false, /* fallback_position */
};
#ifndef HB_NO_OT_SHAPER_MYANMAR_ZAWGYI
/* Ugly Zawgyi encoding.
* Disable all auto processing.
const hb_ot_shaper_t _hb_ot_shaper_myanmar_zawgyi =
{
nullptr, /* collect_features */
nullptr, /* override_features */
nullptr, /* data_create */
nullptr, /* data_destroy */
nullptr, /* preprocess_text */
nullptr, /* postprocess_glyphs */
nullptr, /* decompose */
nullptr, /* compose */
nullptr, /* setup_masks */
nullptr, /* reorder_marks */
HB_TAG_NONE, /* gpos_tag */
HB_OT_SHAPE_NORMALIZATION_MODE_NONE,
HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
false, /* fallback_position */
};
#endif
#endif