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harfbuzz/src/hb-ot-shaper-use.cc

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/*
* Copyright © 2015 Mozilla Foundation.
* Copyright © 2015 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.
*
* Mozilla Author(s): Jonathan Kew
* Google Author(s): Behdad Esfahbod
*/
#include "hb.hh"
#ifndef HB_NO_OT_SHAPE
#include "hb-ot-shaper-use-machine.hh"
#include "hb-ot-shaper-use-table.hh"
#include "hb-ot-shaper-arabic.hh"
#include "hb-ot-shaper-arabic-joining-list.hh"
#include "hb-ot-shaper-vowel-constraints.hh"
/*
* Universal Shaping Engine.
* https://docs.microsoft.com/en-us/typography/script-development/use
*/
static const hb_tag_t
use_basic_features[] =
{
/*
* Basic features.
* These features are applied all at once, before reordering, constrained
* to the syllable.
*/
HB_TAG('r','k','r','f'),
HB_TAG('a','b','v','f'),
HB_TAG('b','l','w','f'),
HB_TAG('h','a','l','f'),
HB_TAG('p','s','t','f'),
HB_TAG('v','a','t','u'),
HB_TAG('c','j','c','t'),
};
static const hb_tag_t
use_topographical_features[] =
{
HB_TAG('i','s','o','l'),
HB_TAG('i','n','i','t'),
HB_TAG('m','e','d','i'),
HB_TAG('f','i','n','a'),
};
/* Same order as use_topographical_features. */
enum joining_form_t {
JOINING_FORM_ISOL,
JOINING_FORM_INIT,
JOINING_FORM_MEDI,
JOINING_FORM_FINA,
_JOINING_FORM_NONE
};
static const hb_tag_t
use_other_features[] =
{
/*
* Other features.
* These features are applied all at once, after reordering and
* clearing syllables.
*/
HB_TAG('a','b','v','s'),
HB_TAG('b','l','w','s'),
HB_TAG('h','a','l','n'),
HB_TAG('p','r','e','s'),
HB_TAG('p','s','t','s'),
};
static bool
setup_syllables_use (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static bool
record_rphf_use (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static bool
record_pref_use (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static bool
reorder_use (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static void
collect_features_use (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_use);
/* "Default glyph pre-processing group" */
map->enable_feature (HB_TAG('l','o','c','l'), F_PER_SYLLABLE);
map->enable_feature (HB_TAG('c','c','m','p'), F_PER_SYLLABLE);
map->enable_feature (HB_TAG('n','u','k','t'), F_PER_SYLLABLE);
map->enable_feature (HB_TAG('a','k','h','n'), F_MANUAL_ZWJ | F_PER_SYLLABLE);
/* "Reordering group" */
map->add_gsub_pause (_hb_clear_substitution_flags);
map->add_feature (HB_TAG('r','p','h','f'), F_MANUAL_ZWJ | F_PER_SYLLABLE);
map->add_gsub_pause (record_rphf_use);
map->add_gsub_pause (_hb_clear_substitution_flags);
map->enable_feature (HB_TAG('p','r','e','f'), F_MANUAL_ZWJ | F_PER_SYLLABLE);
map->add_gsub_pause (record_pref_use);
/* "Orthographic unit shaping group" */
for (unsigned int i = 0; i < ARRAY_LENGTH (use_basic_features); i++)
map->enable_feature (use_basic_features[i], F_MANUAL_ZWJ | F_PER_SYLLABLE);
map->add_gsub_pause (reorder_use);
map->add_gsub_pause (hb_syllabic_clear_var); // Don't need syllables anymore, use stop to free buffer var
/* "Topographical features" */
for (unsigned int i = 0; i < ARRAY_LENGTH (use_topographical_features); i++)
map->add_feature (use_topographical_features[i]);
map->add_gsub_pause (nullptr);
/* "Standard typographic presentation" */
for (unsigned int i = 0; i < ARRAY_LENGTH (use_other_features); i++)
map->enable_feature (use_other_features[i], F_MANUAL_ZWJ);
}
struct use_shape_plan_t
{
hb_mask_t rphf_mask;
arabic_shape_plan_t *arabic_plan;
};
static void *
data_create_use (const hb_ot_shape_plan_t *plan)
{
use_shape_plan_t *use_plan = (use_shape_plan_t *) hb_calloc (1, sizeof (use_shape_plan_t));
if (unlikely (!use_plan))
return nullptr;
use_plan->rphf_mask = plan->map.get_1_mask (HB_TAG('r','p','h','f'));
if (has_arabic_joining (plan->props.script))
{
use_plan->arabic_plan = (arabic_shape_plan_t *) data_create_arabic (plan);
if (unlikely (!use_plan->arabic_plan))
{
hb_free (use_plan);
return nullptr;
}
}
return use_plan;
}
static void
data_destroy_use (void *data)
{
use_shape_plan_t *use_plan = (use_shape_plan_t *) data;
if (use_plan->arabic_plan)
data_destroy_arabic (use_plan->arabic_plan);
hb_free (data);
}
static void
setup_masks_use (const hb_ot_shape_plan_t *plan,
hb_buffer_t *buffer,
hb_font_t *font HB_UNUSED)
{
const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
/* Do this before allocating use_category(). */
if (use_plan->arabic_plan)
{
setup_masks_arabic_plan (use_plan->arabic_plan, buffer, plan->props.script);
}
HB_BUFFER_ALLOCATE_VAR (buffer, use_category);
/* 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++)
info[i].use_category() = hb_use_get_category (info[i].codepoint);
}
static void
setup_rphf_mask (const hb_ot_shape_plan_t *plan,
hb_buffer_t *buffer)
{
const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
hb_mask_t mask = use_plan->rphf_mask;
if (!mask) return;
hb_glyph_info_t *info = buffer->info;
foreach_syllable (buffer, start, end)
{
unsigned int limit = info[start].use_category() == USE(R) ? 1 : hb_min (3u, end - start);
for (unsigned int i = start; i < start + limit; i++)
info[i].mask |= mask;
}
}
static void
setup_topographical_masks (const hb_ot_shape_plan_t *plan,
hb_buffer_t *buffer)
{
const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
if (use_plan->arabic_plan)
return;
static_assert ((JOINING_FORM_INIT < 4 && JOINING_FORM_ISOL < 4 && JOINING_FORM_MEDI < 4 && JOINING_FORM_FINA < 4), "");
hb_mask_t masks[4], all_masks = 0;
for (unsigned int i = 0; i < 4; i++)
{
masks[i] = plan->map.get_1_mask (use_topographical_features[i]);
if (masks[i] == plan->map.get_global_mask ())
masks[i] = 0;
all_masks |= masks[i];
}
if (!all_masks)
return;
hb_mask_t other_masks = ~all_masks;
unsigned int last_start = 0;
joining_form_t last_form = _JOINING_FORM_NONE;
hb_glyph_info_t *info = buffer->info;
foreach_syllable (buffer, start, end)
{
use_syllable_type_t syllable_type = (use_syllable_type_t) (info[start].syllable() & 0x0F);
switch (syllable_type)
{
case use_hieroglyph_cluster:
case use_non_cluster:
/* These don't join. Nothing to do. */
last_form = _JOINING_FORM_NONE;
break;
case use_virama_terminated_cluster:
case use_sakot_terminated_cluster:
case use_standard_cluster:
case use_number_joiner_terminated_cluster:
case use_numeral_cluster:
case use_symbol_cluster:
case use_broken_cluster:
bool join = last_form == JOINING_FORM_FINA || last_form == JOINING_FORM_ISOL;
if (join)
{
/* Fixup previous syllable's form. */
last_form = last_form == JOINING_FORM_FINA ? JOINING_FORM_MEDI : JOINING_FORM_INIT;
for (unsigned int i = last_start; i < start; i++)
info[i].mask = (info[i].mask & other_masks) | masks[last_form];
}
/* Form for this syllable. */
last_form = join ? JOINING_FORM_FINA : JOINING_FORM_ISOL;
for (unsigned int i = start; i < end; i++)
info[i].mask = (info[i].mask & other_masks) | masks[last_form];
break;
}
last_start = start;
}
}
static bool
setup_syllables_use (const hb_ot_shape_plan_t *plan,
hb_font_t *font HB_UNUSED,
hb_buffer_t *buffer)
{
HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
find_syllables_use (buffer);
foreach_syllable (buffer, start, end)
buffer->unsafe_to_break (start, end);
setup_rphf_mask (plan, buffer);
setup_topographical_masks (plan, buffer);
return false;
}
static bool
record_rphf_use (const hb_ot_shape_plan_t *plan,
hb_font_t *font HB_UNUSED,
hb_buffer_t *buffer)
{
const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
hb_mask_t mask = use_plan->rphf_mask;
if (!mask) return false;
hb_glyph_info_t *info = buffer->info;
foreach_syllable (buffer, start, end)
{
/* Mark a substituted repha as USE(R). */
for (unsigned int i = start; i < end && (info[i].mask & mask); i++)
if (_hb_glyph_info_substituted (&info[i]))
{
info[i].use_category() = USE(R);
break;
}
}
return false;
}
static bool
record_pref_use (const hb_ot_shape_plan_t *plan HB_UNUSED,
hb_font_t *font HB_UNUSED,
hb_buffer_t *buffer)
{
hb_glyph_info_t *info = buffer->info;
foreach_syllable (buffer, start, end)
{
/* Mark a substituted pref as VPre, as they behave the same way. */
for (unsigned int i = start; i < end; i++)
if (_hb_glyph_info_substituted (&info[i]))
{
info[i].use_category() = USE(VPre);
break;
}
}
return false;
}
static inline bool
is_halant_use (const hb_glyph_info_t &info)
{
return (info.use_category() == USE(H) || info.use_category() == USE(HVM) || info.use_category() == USE(IS)) &&
!_hb_glyph_info_ligated (&info);
}
static void
reorder_syllable_use (hb_buffer_t *buffer, unsigned int start, unsigned int end)
{
use_syllable_type_t syllable_type = (use_syllable_type_t) (buffer->info[start].syllable() & 0x0F);
/* Only a few syllable types need reordering. */
if (unlikely (!(FLAG_UNSAFE (syllable_type) &
(FLAG (use_virama_terminated_cluster) |
FLAG (use_sakot_terminated_cluster) |
FLAG (use_standard_cluster) |
FLAG (use_symbol_cluster) |
FLAG (use_broken_cluster) |
0))))
return;
hb_glyph_info_t *info = buffer->info;
#define POST_BASE_FLAGS64 (FLAG64 (USE(FAbv)) | \
FLAG64 (USE(FBlw)) | \
FLAG64 (USE(FPst)) | \
FLAG64 (USE(MAbv)) | \
FLAG64 (USE(MBlw)) | \
FLAG64 (USE(MPst)) | \
FLAG64 (USE(MPre)) | \
FLAG64 (USE(VAbv)) | \
FLAG64 (USE(VBlw)) | \
FLAG64 (USE(VPst)) | \
FLAG64 (USE(VPre)) | \
FLAG64 (USE(VMAbv)) | \
FLAG64 (USE(VMBlw)) | \
FLAG64 (USE(VMPst)) | \
FLAG64 (USE(VMPre)))
/* Move things forward. */
if (info[start].use_category() == USE(R) && end - start > 1)
{
/* Got a repha. Reorder it towards the end, but before the first post-base
* glyph. */
for (unsigned int i = start + 1; i < end; i++)
{
bool is_post_base_glyph = (FLAG64_UNSAFE (info[i].use_category()) & POST_BASE_FLAGS64) ||
is_halant_use (info[i]);
if (is_post_base_glyph || i == end - 1)
{
/* If we hit a post-base glyph, move before it; otherwise move to the
* end. Shift things in between backward. */
if (is_post_base_glyph)
i--;
buffer->merge_clusters (start, i + 1);
hb_glyph_info_t t = info[start];
memmove (&info[start], &info[start + 1], (i - start) * sizeof (info[0]));
info[i] = t;
break;
}
}
}
/* Move things back. */
unsigned int j = start;
for (unsigned int i = start; i < end; i++)
{
uint32_t flag = FLAG_UNSAFE (info[i].use_category());
if (is_halant_use (info[i]))
{
/* If we hit a halant, move after it; otherwise move to the beginning, and
* shift things in between forward. */
j = i + 1;
}
else if (((flag) & (FLAG (USE(VPre)) | FLAG (USE(VMPre)))) &&
/* Only move the first component of a MultipleSubst. */
0 == _hb_glyph_info_get_lig_comp (&info[i]) &&
j < i)
{
buffer->merge_clusters (j, i + 1);
hb_glyph_info_t t = info[i];
memmove (&info[j + 1], &info[j], (i - j) * sizeof (info[0]));
info[j] = t;
}
}
}
static bool
reorder_use (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer)
{
bool ret = false;
if (buffer->message (font, "start reordering USE"))
{
if (hb_syllabic_insert_dotted_circles (font, buffer,
use_broken_cluster,
USE(B),
USE(R)))
ret = true;
foreach_syllable (buffer, start, end)
reorder_syllable_use (buffer, start, end);
(void) buffer->message (font, "end reordering USE");
}
HB_BUFFER_DEALLOCATE_VAR (buffer, use_category);
return ret;
}
static void
preprocess_text_use (const hb_ot_shape_plan_t *plan,
hb_buffer_t *buffer,
hb_font_t *font)
{
_hb_preprocess_text_vowel_constraints (plan, buffer, font);
}
static bool
compose_use (const hb_ot_shape_normalize_context_t *c,
hb_codepoint_t a,
hb_codepoint_t b,
hb_codepoint_t *ab)
{
/* Avoid recomposing split matras. */
if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (c->unicode->general_category (a)))
return false;
return (bool)c->unicode->compose (a, b, ab);
}
const hb_ot_shaper_t _hb_ot_shaper_use =
{
collect_features_use,
nullptr, /* override_features */
data_create_use,
data_destroy_use,
preprocess_text_use,
nullptr, /* postprocess_glyphs */
nullptr, /* decompose */
compose_use,
setup_masks_use,
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 */
};
#endif
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