Sweden-Number/dlls/dwrite/shapers/arabic.c

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/*
* Copyright HarfBuzz Project authors
* Copyright 2020 Nikolay Sivov for CodeWeavers
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include "dwrite_private.h"
#include "scripts.h"
static const unsigned int arabic_features[] =
{
DWRITE_MAKE_OPENTYPE_TAG('i','s','o','l'),
DWRITE_MAKE_OPENTYPE_TAG('f','i','n','a'),
DWRITE_MAKE_OPENTYPE_TAG('f','i','n','2'),
DWRITE_MAKE_OPENTYPE_TAG('f','i','n','3'),
DWRITE_MAKE_OPENTYPE_TAG('m','e','d','i'),
DWRITE_MAKE_OPENTYPE_TAG('m','e','d','2'),
DWRITE_MAKE_OPENTYPE_TAG('i','n','i','t'),
};
enum arabic_shaping_action
{
ISOL,
FINA,
FIN2,
FIN3,
MEDI,
MED2,
INIT,
NONE,
NUM_FEATURES = NONE,
};
static BOOL feature_is_syriac(unsigned int tag)
{
return tag == arabic_features[FIN2] || tag == arabic_features[FIN3] ||
tag == arabic_features[MED2];
}
static void arabic_collect_features(struct scriptshaping_context *context,
struct shaping_features *features)
{
unsigned int i;
shape_enable_feature(features, DWRITE_MAKE_OPENTYPE_TAG('c','c','m','p'), 0);
shape_enable_feature(features, DWRITE_MAKE_OPENTYPE_TAG('l','o','c','l'), 0);
shape_start_next_stage(features, NULL);
for (i = 0; i < ARRAY_SIZE(arabic_features); ++i)
{
unsigned int flags = context->script == Script_Arabic && !feature_is_syriac(arabic_features[i]) ?
FEATURE_HAS_FALLBACK : 0;
shape_add_feature_full(features, arabic_features[i], flags, 1);
shape_start_next_stage(features, NULL);
}
shape_enable_feature(features, DWRITE_MAKE_OPENTYPE_TAG('r','l','i','g'), FEATURE_MANUAL_ZWJ | FEATURE_HAS_FALLBACK);
shape_enable_feature(features, DWRITE_MAKE_OPENTYPE_TAG('r','c','l','t'), FEATURE_MANUAL_ZWJ);
shape_enable_feature(features, DWRITE_MAKE_OPENTYPE_TAG('c','a','l','t'), FEATURE_MANUAL_ZWJ);
shape_start_next_stage(features, NULL);
shape_enable_feature(features, DWRITE_MAKE_OPENTYPE_TAG('m','s','e','t'), 0);
}
enum arabic_joining_type
{
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,
JOINING_TYPES = 6,
JOINING_TYPE_T = 6,
};
static const struct arabic_state_table_entry
{
unsigned char prev_action;
unsigned char curr_action;
unsigned char next_state;
}
arabic_state_table[][JOINING_TYPES] =
{
/* U, L, R, D, ALAPH, 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}, }
};
extern const unsigned short arabic_shaping_table[] DECLSPEC_HIDDEN;
static unsigned short arabic_get_joining_type(WCHAR ch)
{
const unsigned short *table = arabic_shaping_table;
return table[table[table[ch >> 8] + ((ch >> 4) & 0x0f)] + (ch & 0xf)];
}
static void arabic_set_shaping_action(struct scriptshaping_context *context,
unsigned int idx, enum arabic_shaping_action action)
{
context->glyph_infos[idx].props &= ~(0xf << 16);
context->glyph_infos[idx].props |= (action & 0xf) << 16;
}
static enum arabic_shaping_action arabic_get_shaping_action(const struct scriptshaping_context *context,
unsigned int idx)
{
return (context->glyph_infos[idx].props >> 16) & 0xf;
}
static void arabic_setup_masks(struct scriptshaping_context *context,
const struct shaping_features *features)
{
unsigned int i, prev = ~0u, state = 0;
unsigned int masks[NUM_FEATURES];
for (i = 0; i < context->glyph_count; ++i)
{
unsigned short this_type = arabic_get_joining_type(context->glyph_infos[i].codepoint);
const struct arabic_state_table_entry *entry;
if (this_type == JOINING_TYPE_T)
{
arabic_set_shaping_action(context, i, NONE);
continue;
}
entry = &arabic_state_table[state][this_type];
if (entry->prev_action != NONE && prev != ~0u)
arabic_set_shaping_action(context, prev, entry->prev_action);
arabic_set_shaping_action(context, i, entry->curr_action);
prev = i;
state = entry->next_state;
}
for (i = 0; i < ARRAY_SIZE(masks); ++i)
masks[i] = shape_get_feature_1_mask(features, arabic_features[i]);
/* Unaffected glyphs get action NONE with zero mask. */
for (i = 0; i < context->glyph_count; ++i)
{
enum arabic_shaping_action action = arabic_get_shaping_action(context, i);
if (action != NONE)
opentype_layout_unsafe_to_break(context, i, i + 1);
context->glyph_infos[i].mask |= masks[action];
}
}
const struct shaper arabic_shaper =
{
arabic_collect_features,
arabic_setup_masks,
};