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

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/*
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* Copyright © 2010 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"
HB_BEGIN_DECLS
/* buffer var allocations */
#define arabic_shaping_action() var2.u32 /* arabic shaping action */
/*
* Bits used in the joining tables
*/
enum {
JOINING_TYPE_U = 0,
JOINING_TYPE_R = 1,
JOINING_TYPE_D = 2,
JOINING_TYPE_C = JOINING_TYPE_D,
JOINING_GROUP_ALAPH = 3,
JOINING_GROUP_DALATH_RISH = 4,
NUM_STATE_MACHINE_COLS = 5,
/* We deliberately don't have a JOINING_TYPE_L since that's unused in Unicode. */
JOINING_TYPE_T = 6,
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JOINING_TYPE_X = 7 /* 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)
{
/* TODO Macroize the magic bit operations */
if (likely (JOINING_TABLE_FIRST <= u && u <= 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 */
if (unlikely (0x1800 <= u && u <= 0x18AF))
{
/* All letters, SIBE SYLLABLE BOUNDARY MARKER, and NIRUGU are D */
if (gen_cat == HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER || u == 0x1807 || u == 0x180A)
return JOINING_TYPE_D;
}
if (unlikely ((u & ~(0x200C^0x200D)) == 0x200C)) {
return u == 0x200C ? JOINING_TYPE_U : JOINING_TYPE_C;
}
return ((1<<gen_cat) & ((1<<HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)|(1<<HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK)|(1<<HB_UNICODE_GENERAL_CATEGORY_FORMAT))) ?
JOINING_TYPE_T : JOINING_TYPE_U;
}
static const hb_tag_t arabic_syriac_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,
COMMON_NUM_FEATURES = 4,
SYRIAC_NUM_FEATURES = 7,
TOTAL_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_R, jt_D, jg_ALAPH, jg_DALATH_RISH */
/* State 0: prev was U, not willing to join. */
{ {NONE,NONE,0}, {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,1}, {NONE,ISOL,2}, {NONE,FIN2,5}, {NONE,ISOL,6}, },
/* State 2: prev was D/ISOL, willing to join. */
{ {NONE,NONE,0}, {INIT,FINA,1}, {INIT,FINA,3}, {INIT,FINA,4}, {INIT,FINA,6}, },
/* State 3: prev was D/FINA, willing to join. */
{ {NONE,NONE,0}, {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}, {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}, {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,1}, {NONE,ISOL,2}, {NONE,FIN3,5}, {NONE,ISOL,6}, }
};
void
_hb_ot_shape_complex_collect_features_arabic (hb_ot_map_builder_t *map, const hb_segment_properties_t *props)
{
/* 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.
*/
map->add_bool_feature (HB_TAG('c','c','m','p'));
map->add_gsub_pause (NULL, NULL);
unsigned int num_features = props->script == HB_SCRIPT_SYRIAC ? SYRIAC_NUM_FEATURES : COMMON_NUM_FEATURES;
for (unsigned int i = 0; i < num_features; i++)
map->add_bool_feature (arabic_syriac_features[i], false);
map->add_gsub_pause (NULL, NULL);
map->add_bool_feature (HB_TAG('r','l','i','g'));
map->add_gsub_pause (NULL, NULL);
map->add_bool_feature (HB_TAG('c','a','l','t'));
map->add_gsub_pause (NULL, NULL);
/* ArabicOT spec enables 'cswh' for Arabic where as for basic shaper it's disabled by default. */
map->add_bool_feature (HB_TAG('c','s','w','h'));
}
void
_hb_ot_shape_complex_setup_masks_arabic (hb_ot_map_t *map, hb_buffer_t *buffer)
{
unsigned int count = buffer->len;
unsigned int prev = 0, state = 0;
for (unsigned int i = 0; i < count; i++)
{
unsigned int this_type = get_joining_type (buffer->info[i].codepoint, (hb_unicode_general_category_t) buffer->info[i].general_category());
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)
buffer->info[prev].arabic_shaping_action() = entry->prev_action;
buffer->info[i].arabic_shaping_action() = entry->curr_action;
prev = i;
state = entry->next_state;
}
hb_mask_t mask_array[TOTAL_NUM_FEATURES + 1] = {0};
unsigned int num_masks = buffer->props.script == HB_SCRIPT_SYRIAC ? SYRIAC_NUM_FEATURES : COMMON_NUM_FEATURES;
for (unsigned int i = 0; i < num_masks; i++)
mask_array[i] = map->get_1_mask (arabic_syriac_features[i]);
for (unsigned int i = 0; i < count; i++)
buffer->info[i].mask |= mask_array[buffer->info[i].arabic_shaping_action()];
}
HB_END_DECLS