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

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/*
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* Copyright © 2010,2012 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
*/
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#include "hb-ot-shape-complex-private.hh"
#include "hb-ot-shape-private.hh"
/* buffer var allocations */
#define arabic_shaping_action() complex_var_u8_0() /* arabic shaping action */
/*
* Bits used in the joining tables
*/
enum {
JOINING_TYPE_U = 0,
JOINING_TYPE_L = 1,
JOINING_TYPE_R = 2,
JOINING_TYPE_D = 3,
JOINING_TYPE_C = JOINING_TYPE_D,
JOINING_GROUP_ALAPH = 4,
JOINING_GROUP_DALATH_RISH = 5,
NUM_STATE_MACHINE_COLS = 6,
JOINING_TYPE_T = 7,
JOINING_TYPE_X = 8 /* means: use general-category to choose between U or T. */
};
/*
* Joining types:
*/
#include "hb-ot-shape-complex-arabic-table.hh"
static unsigned int get_joining_type (hb_codepoint_t u, hb_unicode_general_category_t gen_cat)
{
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if (likely (hb_in_range<hb_codepoint_t> (u, JOINING_TABLE_FIRST, JOINING_TABLE_LAST))) {
unsigned int j_type = joining_table[u - JOINING_TABLE_FIRST];
if (likely (j_type != JOINING_TYPE_X))
return j_type;
}
/* Mongolian joining data is not in ArabicJoining.txt yet. */
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if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x1800, 0x18AF)))
{
if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x1880, 0x1886)))
return JOINING_TYPE_U;
/* All letters, SIBE SYLLABLE BOUNDARY MARKER, and NIRUGU are D */
if ((FLAG(gen_cat) & (FLAG (HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER) |
FLAG (HB_UNICODE_GENERAL_CATEGORY_MODIFIER_LETTER)))
|| u == 0x1807 || u == 0x180A)
return JOINING_TYPE_D;
}
/* 'Phags-pa joining data is not in ArabicJoining.txt yet. */
if (unlikely (hb_in_range<hb_codepoint_t> (u, 0xA840, 0xA872)))
{
if (unlikely (u == 0xA872))
return JOINING_TYPE_L;
return JOINING_TYPE_D;
}
if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x200C, 0x200D)))
{
return u == 0x200C ? JOINING_TYPE_U : JOINING_TYPE_C;
}
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return (FLAG(gen_cat) & (FLAG(HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) | FLAG(HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) | FLAG(HB_UNICODE_GENERAL_CATEGORY_FORMAT))) ?
JOINING_TYPE_T : JOINING_TYPE_U;
}
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static const hb_tag_t arabic_features[] =
{
HB_TAG('i','n','i','t'),
HB_TAG('m','e','d','i'),
HB_TAG('f','i','n','a'),
HB_TAG('i','s','o','l'),
/* Syriac */
HB_TAG('m','e','d','2'),
HB_TAG('f','i','n','2'),
HB_TAG('f','i','n','3'),
HB_TAG_NONE
};
/* Same order as the feature array */
enum {
INIT,
MEDI,
FINA,
ISOL,
/* Syriac */
MED2,
FIN2,
FIN3,
NONE,
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ARABIC_NUM_FEATURES = NONE
};
static const struct arabic_state_table_entry {
uint8_t prev_action;
uint8_t curr_action;
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uint16_t next_state;
} arabic_state_table[][NUM_STATE_MACHINE_COLS] =
{
/* jt_U, jt_L, jt_R, jt_D, jg_ALAPH, jg_DALATH_RISH */
/* State 0: prev was U, not willing to join. */
{ {NONE,NONE,0}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,6}, },
/* State 1: prev was R or ISOL/ALAPH, not willing to join. */
{ {NONE,NONE,0}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,FIN2,5}, {NONE,ISOL,6}, },
/* State 2: prev was D/L in ISOL form, willing to join. */
{ {NONE,NONE,0}, {NONE,ISOL,2}, {INIT,FINA,1}, {INIT,FINA,3}, {INIT,FINA,4}, {INIT,FINA,6}, },
/* State 3: prev was D in FINA form, willing to join. */
{ {NONE,NONE,0}, {NONE,ISOL,2}, {MEDI,FINA,1}, {MEDI,FINA,3}, {MEDI,FINA,4}, {MEDI,FINA,6}, },
/* State 4: prev was FINA ALAPH, not willing to join. */
{ {NONE,NONE,0}, {NONE,ISOL,2}, {MED2,ISOL,1}, {MED2,ISOL,2}, {MED2,FIN2,5}, {MED2,ISOL,6}, },
/* State 5: prev was FIN2/FIN3 ALAPH, not willing to join. */
{ {NONE,NONE,0}, {NONE,ISOL,2}, {ISOL,ISOL,1}, {ISOL,ISOL,2}, {ISOL,FIN2,5}, {ISOL,ISOL,6}, },
/* State 6: prev was DALATH/RISH, not willing to join. */
{ {NONE,NONE,0}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,FIN3,5}, {NONE,ISOL,6}, }
};
static void
arabic_fallback_shape (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static void
collect_features_arabic (hb_ot_shape_planner_t *plan)
{
hb_ot_map_builder_t *map = &plan->map;
/* For Language forms (in ArabicOT speak), we do the iso/fina/medi/init together,
* then rlig and calt each in their own stage. This makes IranNastaliq's ALLAH
* ligature work correctly. It's unfortunate though...
*
* This also makes Arial Bold in Windows7 work. See:
* https://bugzilla.mozilla.org/show_bug.cgi?id=644184
*
* TODO: Add test cases for these two.
*/
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map->add_global_bool_feature (HB_TAG('c','c','m','p'));
map->add_global_bool_feature (HB_TAG('l','o','c','l'));
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map->add_gsub_pause (NULL);
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for (unsigned int i = 0; i < ARABIC_NUM_FEATURES; i++)
map->add_feature (arabic_features[i], 1, i < 4 ? F_HAS_FALLBACK : F_NONE); /* The first four features have fallback. */
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map->add_gsub_pause (NULL);
map->add_feature (HB_TAG('r','l','i','g'), 1, F_GLOBAL|F_HAS_FALLBACK);
map->add_gsub_pause (arabic_fallback_shape);
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map->add_global_bool_feature (HB_TAG('c','a','l','t'));
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map->add_gsub_pause (NULL);
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map->add_global_bool_feature (HB_TAG('c','s','w','h'));
map->add_global_bool_feature (HB_TAG('m','s','e','t'));
}
#include "hb-ot-shape-complex-arabic-fallback.hh"
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struct arabic_shape_plan_t
{
ASSERT_POD ();
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/* The "+ 1" in the next array is to accommodate for the "NONE" command,
* which is not an OpenType feature, but this simplifies the code by not
* having to do a "if (... < NONE) ..." and just rely on the fact that
* mask_array[NONE] == 0. */
hb_mask_t mask_array[ARABIC_NUM_FEATURES + 1];
bool do_fallback;
arabic_fallback_plan_t *fallback_plan;
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};
static void *
data_create_arabic (const hb_ot_shape_plan_t *plan)
{
arabic_shape_plan_t *arabic_plan = (arabic_shape_plan_t *) calloc (1, sizeof (arabic_shape_plan_t));
if (unlikely (!arabic_plan))
return NULL;
arabic_plan->do_fallback = plan->props.script == HB_SCRIPT_ARABIC;
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for (unsigned int i = 0; i < ARABIC_NUM_FEATURES; i++) {
arabic_plan->mask_array[i] = plan->map.get_1_mask (arabic_features[i]);
if (i < 4)
arabic_plan->do_fallback = arabic_plan->do_fallback && plan->map.needs_fallback (arabic_features[i]);
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}
return arabic_plan;
}
static void
data_destroy_arabic (void *data)
{
arabic_shape_plan_t *arabic_plan = (arabic_shape_plan_t *) data;
arabic_fallback_plan_destroy (arabic_plan->fallback_plan);
free (data);
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}
static void
arabic_joining (hb_buffer_t *buffer)
{
unsigned int count = buffer->len;
unsigned int prev = (unsigned int) -1, state = 0;
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HB_BUFFER_ALLOCATE_VAR (buffer, arabic_shaping_action);
/* Check pre-context */
if (!(buffer->flags & HB_BUFFER_FLAG_BOT))
for (unsigned int i = 0; i < buffer->context_len[0]; i++)
{
unsigned int this_type = get_joining_type (buffer->context[0][i], buffer->unicode->general_category (buffer->context[0][i]));
if (unlikely (this_type == JOINING_TYPE_T))
continue;
const arabic_state_table_entry *entry = &arabic_state_table[state][this_type];
state = entry->next_state;
break;
}
for (unsigned int i = 0; i < count; i++)
{
unsigned int this_type = get_joining_type (buffer->info[i].codepoint, _hb_glyph_info_get_general_category (&buffer->info[i]));
if (unlikely (this_type == JOINING_TYPE_T)) {
buffer->info[i].arabic_shaping_action() = NONE;
continue;
}
const arabic_state_table_entry *entry = &arabic_state_table[state][this_type];
if (entry->prev_action != NONE && prev != (unsigned int) -1)
buffer->info[prev].arabic_shaping_action() = entry->prev_action;
buffer->info[i].arabic_shaping_action() = entry->curr_action;
prev = i;
state = entry->next_state;
}
if (!(buffer->flags & HB_BUFFER_FLAG_EOT))
for (unsigned int i = 0; i < buffer->context_len[1]; i++)
{
unsigned int this_type = get_joining_type (buffer->context[1][i], buffer->unicode->general_category (buffer->context[1][i]));
if (unlikely (this_type == JOINING_TYPE_T))
continue;
const arabic_state_table_entry *entry = &arabic_state_table[state][this_type];
if (entry->prev_action != NONE && prev != (unsigned int) -1)
buffer->info[prev].arabic_shaping_action() = entry->prev_action;
break;
}
HB_BUFFER_DEALLOCATE_VAR (buffer, arabic_shaping_action);
}
static void
setup_masks_arabic (const hb_ot_shape_plan_t *plan,
hb_buffer_t *buffer,
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hb_font_t *font HB_UNUSED)
{
const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data;
arabic_joining (buffer);
unsigned int count = buffer->len;
for (unsigned int i = 0; i < count; i++)
buffer->info[i].mask |= arabic_plan->mask_array[buffer->info[i].arabic_shaping_action()];
}
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static void
arabic_fallback_shape (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer)
{
const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data;
if (!arabic_plan->do_fallback)
return;
retry:
arabic_fallback_plan_t *fallback_plan = (arabic_fallback_plan_t *) hb_atomic_ptr_get (&arabic_plan->fallback_plan);
if (unlikely (!fallback_plan))
{
/* This sucks. We need a font to build the fallback plan... */
fallback_plan = arabic_fallback_plan_create (plan, font);
if (unlikely (!hb_atomic_ptr_cmpexch (&(const_cast<arabic_shape_plan_t *> (arabic_plan))->fallback_plan, NULL, fallback_plan))) {
arabic_fallback_plan_destroy (fallback_plan);
goto retry;
}
}
arabic_fallback_plan_shape (fallback_plan, font, buffer);
}
const hb_ot_complex_shaper_t _hb_ot_complex_shaper_arabic =
{
"arabic",
collect_features_arabic,
NULL, /* override_features */
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data_create_arabic,
data_destroy_arabic,
NULL, /* preprocess_text_arabic */
NULL, /* normalization_preference */
NULL, /* decompose */
NULL, /* compose */
setup_masks_arabic,
HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE,
true, /* fallback_position */
};