/*
* 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-ot-shape-complex-use-private.hh"
#include "hb-ot-shape-complex-arabic-private.hh"
/* buffer var allocations */
#define use_category() complex_var_u8_0()
/*
* Universal Shaping Engine.
* https://www.microsoft.com/typography/OpenTypeDev/USE/intro.htm
*/
static const hb_tag_t
basic_features[] =
{
/*
* Basic features.
* These features are applied all at once, before reordering.
*/
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
arabic_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'),
/* The spec doesn't specify these but we apply anyway, since our Arabic shaper
* does. These are only used in Syriac spec. */
HB_TAG('m','e','d','2'),
HB_TAG('f','i','n','2'),
HB_TAG('f','i','n','3'),
};
/* Same order as arabic_features. Don't need Syriac stuff.*/
enum joining_form_t {
ISOL,
INIT,
MEDI,
FINA,
_NONE
};
static const hb_tag_t
other_features[] =
{
/*
* Other features.
* These features are applied all at once, after reordering.
*/
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'),
/* Positioning features, though we don't care about the types. */
HB_TAG('d','i','s','t'),
HB_TAG('a','b','v','m'),
HB_TAG('b','l','w','m'),
};
static void
setup_syllables (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static void
clear_substitution_flags (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static void
record_rphf (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static void
record_pref (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static void
reorder (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);
/* "Default glyph pre-processing group" */
map->add_global_bool_feature (HB_TAG('l','o','c','l'));
map->add_global_bool_feature (HB_TAG('c','c','m','p'));
map->add_global_bool_feature (HB_TAG('n','u','k','t'));
map->add_global_bool_feature (HB_TAG('a','k','h','n'));
/* "Reordering group" */
map->add_gsub_pause (clear_substitution_flags);
map->add_feature (HB_TAG('r','p','h','f'), 1, F_MANUAL_ZWJ);
map->add_gsub_pause (record_rphf);
map->add_gsub_pause (clear_substitution_flags);
map->add_feature (HB_TAG('p','r','e','f'), 1, F_GLOBAL | F_MANUAL_ZWJ);
map->add_gsub_pause (record_pref);
/* "Orthographic unit shaping group" */
for (unsigned int i = 0; i < ARRAY_LENGTH (basic_features); i++)
map->add_feature (basic_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ);
map->add_gsub_pause (reorder);
/* "Topographical features" */
for (unsigned int i = 0; i < ARRAY_LENGTH (arabic_features); i++)
map->add_feature (arabic_features[i], 1, F_NONE);
map->add_gsub_pause (NULL);
/* "Standard typographic presentation" and "Positional feature application" */
for (unsigned int i = 0; i < ARRAY_LENGTH (other_features); i++)
map->add_feature (other_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ);
}
struct use_shape_plan_t
{
ASSERT_POD ();
hb_mask_t rphf_mask;
arabic_shape_plan_t *arabic_plan;
};
static bool
has_arabic_joining (hb_script_t script)
{
/* List of scripts that have data in arabic-table. */
switch ((int) script)
{
/* Unicode-1.1 additions */
case HB_SCRIPT_ARABIC:
/* Unicode-3.0 additions */
case HB_SCRIPT_MONGOLIAN:
case HB_SCRIPT_SYRIAC:
/* Unicode-5.0 additions */
case HB_SCRIPT_NKO:
case HB_SCRIPT_PHAGS_PA:
/* Unicode-6.0 additions */
case HB_SCRIPT_MANDAIC:
/* Unicode-7.0 additions */
case HB_SCRIPT_MANICHAEAN:
case HB_SCRIPT_PSALTER_PAHLAVI:
return true;
default:
return false;
}
}
static void *
data_create_use (const hb_ot_shape_plan_t *plan)
{
use_shape_plan_t *use_plan = (use_shape_plan_t *) calloc (1, sizeof (use_shape_plan_t));
if (unlikely (!use_plan))
return NULL;
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))
{
free (use_plan);
return NULL;
}
}
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);
free (data);
}
enum syllable_type_t {
independent_cluster,
virama_terminated_cluster,
consonant_cluster,
vowel_cluster,
number_joiner_terminated_cluster,
numeral_cluster,
symbol_cluster,
broken_cluster,
};
#include "hb-ot-shape-complex-use-machine.hh"
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_categories (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 : 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;
ASSERT_STATIC (INIT < 4 && ISOL < 4 && MEDI < 4 && 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 (arabic_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 = _NONE;
hb_glyph_info_t *info = buffer->info;
foreach_syllable (buffer, start, end)
{
syllable_type_t syllable_type = (syllable_type_t) (info[start].syllable() & 0x0F);
switch (syllable_type)
{
case independent_cluster:
case symbol_cluster:
/* These don't join. Nothing to do. */
last_form = _NONE;
break;
case virama_terminated_cluster:
case consonant_cluster:
case vowel_cluster:
case number_joiner_terminated_cluster:
case numeral_cluster:
case broken_cluster:
bool join = last_form == FINA || last_form == ISOL;
if (join)
{
/* Fixup previous syllable's form. */
last_form = last_form == FINA ? MEDI : 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 ? FINA : 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 void
setup_syllables (const hb_ot_shape_plan_t *plan,
hb_font_t *font HB_UNUSED,
hb_buffer_t *buffer)
{
find_syllables (buffer);
setup_rphf_mask (plan, buffer);
setup_topographical_masks (plan, buffer);
}
static void
clear_substitution_flags (const hb_ot_shape_plan_t *plan,
hb_font_t *font HB_UNUSED,
hb_buffer_t *buffer)
{
hb_glyph_info_t *info = buffer->info;
unsigned int count = buffer->len;
for (unsigned int i = 0; i < count; i++)
_hb_glyph_info_clear_substituted (&info[i]);
}
static void
record_rphf (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
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)
{
/* 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;
}
}
}
static void
record_pref (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
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;
}
}
}
static inline bool
is_halant (const hb_glyph_info_t &info)
{
return info.use_category() == USE_H && !_hb_glyph_info_ligated (&info);
}
static void
reorder_syllable (hb_buffer_t *buffer, unsigned int start, unsigned int end)
{
syllable_type_t syllable_type = (syllable_type_t) (buffer->info[start].syllable() & 0x0F);
/* Only a few syllable types need reordering. */
if (unlikely (!(FLAG_SAFE (syllable_type) &
(FLAG (virama_terminated_cluster) |
FLAG (consonant_cluster) |
FLAG (vowel_cluster) |
FLAG (broken_cluster) |
0))))
return;
hb_glyph_info_t *info = buffer->info;
#define BASE_FLAGS (FLAG (USE_B) | FLAG (USE_GB) | FLAG (USE_IV))
/* Move things forward. */
if (info[start].use_category() == USE_R && end - start > 1)
{
/* Got a repha. Reorder it to after first base, before first halant. */
for (unsigned int i = start + 1; i < end; i++)
if ((FLAG_UNSAFE (info[i].use_category()) & (BASE_FLAGS)) || is_halant (info[i]))
{
/* If we hit a halant, move before it; otherwise it's a base: move to it's
* place, and shift things in between backward. */
if (is_halant (info[i]))
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 = end;
for (unsigned int i = start; i < end; i++)
{
uint32_t flag = FLAG_UNSAFE (info[i].use_category());
if ((flag & (BASE_FLAGS)) || is_halant (info[i]))
{
/* If we hit a halant, move after it; otherwise it's a base: move to it's
* place, and shift things in between backward. */
if (is_halant (info[i]))
j = i + 1;
else
j = i;
}
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 inline void
insert_dotted_circles (const hb_ot_shape_plan_t *plan HB_UNUSED,
hb_font_t *font,
hb_buffer_t *buffer)
{
/* Note: This loop is extra overhead, but should not be measurable. */
bool has_broken_syllables = false;
unsigned int count = buffer->len;
hb_glyph_info_t *info = buffer->info;
for (unsigned int i = 0; i < count; i++)
if ((info[i].syllable() & 0x0F) == broken_cluster)
{
has_broken_syllables = true;
break;
}
if (likely (!has_broken_syllables))
return;
hb_glyph_info_t dottedcircle = {0};
if (!font->get_nominal_glyph (0x25CCu, &dottedcircle.codepoint))
return;
dottedcircle.use_category() = hb_use_get_categories (0x25CC);
buffer->clear_output ();
buffer->idx = 0;
unsigned int last_syllable = 0;
while (buffer->idx < buffer->len && !buffer->in_error)
{
unsigned int syllable = buffer->cur().syllable();
syllable_type_t syllable_type = (syllable_type_t) (syllable & 0x0F);
if (unlikely (last_syllable != syllable && syllable_type == broken_cluster))
{
last_syllable = syllable;
hb_glyph_info_t ginfo = dottedcircle;
ginfo.cluster = buffer->cur().cluster;
ginfo.mask = buffer->cur().mask;
ginfo.syllable() = buffer->cur().syllable();
/* TODO Set glyph_props? */
/* Insert dottedcircle after possible Repha. */
while (buffer->idx < buffer->len && !buffer->in_error &&
last_syllable == buffer->cur().syllable() &&
buffer->cur().use_category() == USE_R)
buffer->next_glyph ();
buffer->output_info (ginfo);
}
else
buffer->next_glyph ();
}
buffer->swap_buffers ();
}
static void
reorder (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer)
{
insert_dotted_circles (plan, font, buffer);
hb_glyph_info_t *info = buffer->info;
foreach_syllable (buffer, start, end)
reorder_syllable (buffer, start, end);
/* Zero syllables now... */
unsigned int count = buffer->len;
for (unsigned int i = 0; i < count; i++)
info[i].syllable() = 0;
HB_BUFFER_DEALLOCATE_VAR (buffer, use_category);
}
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_complex_shaper_t _hb_ot_complex_shaper_use =
{
"use",
collect_features_use,
NULL, /* override_features */
data_create_use,
data_destroy_use,
NULL, /* preprocess_text */
NULL, /* postprocess_glyphs */
HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
NULL, /* decompose */
compose_use,
setup_masks_use,
HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
false, /* fallback_position */
};