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

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/*
* Copyright © 2011,2012 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
*/
#include "hb-ot-shape-complex-indic-private.hh"
#include "hb-ot-layout-private.hh"
/* buffer var allocations */
#define khmer_category() complex_var_u8_0() /* khmer_category_t */
#define khmer_position() complex_var_u8_1() /* khmer_position_t */
/*
* Khmer shaper.
*/
typedef indic_category_t khmer_category_t;
typedef indic_position_t khmer_position_t;
static inline khmer_position_t
matra_position (khmer_position_t side)
{
switch ((int) side)
{
case POS_PRE_C:
return POS_PRE_M;
case POS_POST_C:
case POS_ABOVE_C:
case POS_BELOW_C:
return POS_AFTER_POST;
default:
return side;
};
}
static inline bool
is_one_of (const hb_glyph_info_t &info, unsigned int flags)
{
/* If it ligated, all bets are off. */
if (_hb_glyph_info_ligated (&info)) return false;
return !!(FLAG_UNSAFE (info.khmer_category()) & flags);
}
static inline bool
is_joiner (const hb_glyph_info_t &info)
{
return is_one_of (info, JOINER_FLAGS);
}
static inline bool
is_consonant (const hb_glyph_info_t &info)
{
return is_one_of (info, CONSONANT_FLAGS | FLAG (OT_V));
}
static inline bool
is_coeng (const hb_glyph_info_t &info)
{
return is_one_of (info, FLAG (OT_Coeng));
}
static inline void
set_khmer_properties (hb_glyph_info_t &info)
{
hb_codepoint_t u = info.codepoint;
unsigned int type = hb_indic_get_categories (u);
khmer_category_t cat = (khmer_category_t) (type & 0x7Fu);
khmer_position_t pos = (khmer_position_t) (type >> 8);
/*
* Re-assign category
*/
if (unlikely (u == 0x17C6u)) cat = OT_N; /* Khmer Bindu doesn't like to be repositioned. */
else if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x17CDu, 0x17D1u) ||
u == 0x17CBu || u == 0x17D3u || u == 0x17DDu)) /* Khmer Various signs */
{
/* These can occur mid-syllable (eg. before matras), even though Unicode marks them as Syllable_Modifier.
* https://github.com/roozbehp/unicode-data/issues/5 */
cat = OT_M;
pos = POS_ABOVE_C;
}
else if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x2010u, 0x2011u))) cat = OT_PLACEHOLDER;
else if (unlikely (u == 0x25CCu)) cat = OT_DOTTEDCIRCLE;
/*
* Re-assign position.
*/
if ((FLAG_UNSAFE (cat) & CONSONANT_FLAGS))
{
pos = POS_BASE_C;
if (u == 0x179Au)
cat = OT_Ra;
}
else if (cat == OT_M)
{
pos = matra_position (pos);
}
else if ((FLAG_UNSAFE (cat) & (FLAG (OT_SM) | FLAG (OT_A) | FLAG (OT_Symbol))))
{
pos = POS_SMVD;
}
info.khmer_category() = cat;
info.khmer_position() = pos;
}
/*
* Things above this line should ideally be moved to the Indic table itself.
*/
/*
* Khmer shaper.
*/
struct feature_list_t {
hb_tag_t tag;
hb_ot_map_feature_flags_t flags;
};
static const feature_list_t
khmer_features[] =
{
/*
* Basic features.
* These features are applied in order, one at a time, after initial_reordering.
*/
{HB_TAG('p','r','e','f'), F_NONE},
{HB_TAG('b','l','w','f'), F_NONE},
{HB_TAG('a','b','v','f'), F_NONE},
{HB_TAG('p','s','t','f'), F_NONE},
{HB_TAG('c','f','a','r'), F_NONE},
/*
* Other features.
* These features are applied all at once, after final_reordering.
* Default Bengali font in Windows for example has intermixed
* lookups for init,pres,abvs,blws features.
*/
{HB_TAG('p','r','e','s'), F_GLOBAL},
{HB_TAG('a','b','v','s'), F_GLOBAL},
{HB_TAG('b','l','w','s'), F_GLOBAL},
{HB_TAG('p','s','t','s'), F_GLOBAL},
/* Positioning features, though we don't care about the types. */
{HB_TAG('d','i','s','t'), F_GLOBAL},
{HB_TAG('a','b','v','m'), F_GLOBAL},
{HB_TAG('b','l','w','m'), F_GLOBAL},
};
/*
* Must be in the same order as the khmer_features array.
*/
enum {
PREF,
BLWF,
ABVF,
PSTF,
CFAR,
_PRES,
_ABVS,
_BLWS,
_PSTS,
_DIST,
_ABVM,
_BLWM,
KHMER_NUM_FEATURES,
KHMER_BASIC_FEATURES = _PRES /* Don't forget to update this! */
};
static void
setup_syllables (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static void
initial_reordering (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static void
final_reordering (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static void
clear_syllables (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer);
static void
collect_features_khmer (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);
map->add_global_bool_feature (HB_TAG('l','o','c','l'));
/* The Indic specs do not require ccmp, but we apply it here since if
* there is a use of it, it's typically at the beginning. */
map->add_global_bool_feature (HB_TAG('c','c','m','p'));
unsigned int i = 0;
map->add_gsub_pause (initial_reordering);
for (; i < KHMER_BASIC_FEATURES; i++) {
map->add_feature (khmer_features[i].tag, 1, khmer_features[i].flags | F_MANUAL_ZWJ | F_MANUAL_ZWNJ);
map->add_gsub_pause (nullptr);
}
map->add_gsub_pause (final_reordering);
for (; i < KHMER_NUM_FEATURES; i++) {
map->add_feature (khmer_features[i].tag, 1, khmer_features[i].flags | F_MANUAL_ZWJ | F_MANUAL_ZWNJ);
}
map->add_global_bool_feature (HB_TAG('c','a','l','t'));
map->add_global_bool_feature (HB_TAG('c','l','i','g'));
map->add_gsub_pause (clear_syllables);
}
static void
override_features_khmer (hb_ot_shape_planner_t *plan)
{
/* Uniscribe does not apply 'kern' in Khmer. */
if (hb_options ().uniscribe_bug_compatible)
{
plan->map.add_feature (HB_TAG('k','e','r','n'), 0, F_GLOBAL);
}
plan->map.add_feature (HB_TAG('l','i','g','a'), 0, F_GLOBAL);
}
struct would_substitute_feature_t
{
inline void init (const hb_ot_map_t *map, hb_tag_t feature_tag, bool zero_context_)
{
zero_context = zero_context_;
map->get_stage_lookups (0/*GSUB*/,
map->get_feature_stage (0/*GSUB*/, feature_tag),
&lookups, &count);
}
inline bool would_substitute (const hb_codepoint_t *glyphs,
unsigned int glyphs_count,
hb_face_t *face) const
{
for (unsigned int i = 0; i < count; i++)
if (hb_ot_layout_lookup_would_substitute_fast (face, lookups[i].index, glyphs, glyphs_count, zero_context))
return true;
return false;
}
private:
const hb_ot_map_t::lookup_map_t *lookups;
unsigned int count;
bool zero_context;
};
struct khmer_shape_plan_t
{
ASSERT_POD ();
inline bool get_virama_glyph (hb_font_t *font, hb_codepoint_t *pglyph) const
{
hb_codepoint_t glyph = virama_glyph;
if (unlikely (virama_glyph == (hb_codepoint_t) -1))
{
if (!font->get_nominal_glyph (0x17D2u, &glyph))
glyph = 0;
/* Technically speaking, the spec says we should apply 'locl' to virama too.
* Maybe one day... */
/* Our get_nominal_glyph() function needs a font, so we can't get the virama glyph
* during shape planning... Instead, overwrite it here. It's safe. Don't worry! */
virama_glyph = glyph;
}
*pglyph = glyph;
return glyph != 0;
}
mutable hb_codepoint_t virama_glyph;
would_substitute_feature_t pref;
hb_mask_t mask_array[KHMER_NUM_FEATURES];
};
static void *
data_create_khmer (const hb_ot_shape_plan_t *plan)
{
khmer_shape_plan_t *khmer_plan = (khmer_shape_plan_t *) calloc (1, sizeof (khmer_shape_plan_t));
if (unlikely (!khmer_plan))
return nullptr;
khmer_plan->virama_glyph = (hb_codepoint_t) -1;
khmer_plan->pref.init (&plan->map, HB_TAG('p','r','e','f'), true);
for (unsigned int i = 0; i < ARRAY_LENGTH (khmer_plan->mask_array); i++)
khmer_plan->mask_array[i] = (khmer_features[i].flags & F_GLOBAL) ?
0 : plan->map.get_1_mask (khmer_features[i].tag);
return khmer_plan;
}
static void
data_destroy_khmer (void *data)
{
free (data);
}
enum syllable_type_t {
consonant_syllable,
broken_cluster,
non_khmer_cluster,
};
#include "hb-ot-shape-complex-khmer-machine.hh"
static void
setup_masks_khmer (const hb_ot_shape_plan_t *plan HB_UNUSED,
hb_buffer_t *buffer,
hb_font_t *font HB_UNUSED)
{
HB_BUFFER_ALLOCATE_VAR (buffer, khmer_category);
HB_BUFFER_ALLOCATE_VAR (buffer, khmer_position);
/* 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++)
set_khmer_properties (info[i]);
}
static void
setup_syllables (const hb_ot_shape_plan_t *plan HB_UNUSED,
hb_font_t *font HB_UNUSED,
hb_buffer_t *buffer)
{
find_syllables (buffer);
foreach_syllable (buffer, start, end)
buffer->unsafe_to_break (start, end);
}
static int
compare_khmer_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb)
{
int a = pa->khmer_position();
int b = pb->khmer_position();
return a < b ? -1 : a == b ? 0 : +1;
}
/* Rules from:
* https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx */
static void
initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan,
hb_face_t *face,
hb_buffer_t *buffer,
unsigned int start, unsigned int end)
{
const khmer_shape_plan_t *khmer_plan = (const khmer_shape_plan_t *) plan->data;
hb_glyph_info_t *info = buffer->info;
/* 1. Khmer shaping assumes that a syllable will begin with a Cons, IndV, or Number. */
/* The first consonant is always the base. */
unsigned int base = start;
info[base].khmer_position() = POS_BASE_C;
/* Mark all subsequent consonants as below. */
for (unsigned int i = base + 1; i < end; i++)
if (is_consonant (info[i]))
info[i].khmer_position() = POS_BELOW_C;
/* Mark final consonants. A final consonant is one appearing after a matra,
* like in Khmer. */
for (unsigned int i = base + 1; i < end; i++)
if (info[i].khmer_category() == OT_M) {
for (unsigned int j = i + 1; j < end; j++)
if (is_consonant (info[j])) {
info[j].khmer_position() = POS_FINAL_C;
break;
}
break;
}
/* Attach misc marks to previous char to move with them. */
{
khmer_position_t last_pos = POS_START;
for (unsigned int i = start; i < end; i++)
{
if ((FLAG_UNSAFE (info[i].khmer_category()) & (JOINER_FLAGS | FLAG (OT_N) | FLAG (OT_RS) | MEDIAL_FLAGS | FLAG (OT_Coeng))))
{
info[i].khmer_position() = last_pos;
if (unlikely (info[i].khmer_category() == OT_H &&
info[i].khmer_position() == POS_PRE_M))
{
/*
* Uniscribe doesn't move the Halant with Left Matra.
* TEST: U+092B,U+093F,U+094DE
* We follow. This is important for the Sinhala
* U+0DDA split matra since it decomposes to U+0DD9,U+0DCA
* where U+0DD9 is a left matra and U+0DCA is the virama.
* We don't want to move the virama with the left matra.
* TEST: U+0D9A,U+0DDA
*/
for (unsigned int j = i; j > start; j--)
if (info[j - 1].khmer_position() != POS_PRE_M) {
info[i].khmer_position() = info[j - 1].khmer_position();
break;
}
}
} else if (info[i].khmer_position() != POS_SMVD) {
last_pos = (khmer_position_t) info[i].khmer_position();
}
}
}
/* For post-base consonants let them own anything before them
* since the last consonant or matra. */
{
unsigned int last = base;
for (unsigned int i = base + 1; i < end; i++)
if (is_consonant (info[i]))
{
for (unsigned int j = last + 1; j < i; j++)
if (info[j].khmer_position() < POS_SMVD)
info[j].khmer_position() = info[i].khmer_position();
last = i;
} else if (info[i].khmer_category() == OT_M)
last = i;
}
{
/* Use syllable() for sort accounting temporarily. */
unsigned int syllable = info[start].syllable();
for (unsigned int i = start; i < end; i++)
info[i].syllable() = i - start;
/* Sit tight, rock 'n roll! */
hb_stable_sort (info + start, end - start, compare_khmer_order);
/* Find base again */
base = end;
for (unsigned int i = start; i < end; i++)
if (info[i].khmer_position() == POS_BASE_C)
{
base = i;
break;
}
/* Note! syllable() is a one-byte field. */
for (unsigned int i = base; i < end; i++)
if (info[i].syllable() != 255)
{
unsigned int max = i;
unsigned int j = start + info[i].syllable();
while (j != i)
{
max = MAX (max, j);
unsigned int next = start + info[j].syllable();
info[j].syllable() = 255; /* So we don't process j later again. */
j = next;
}
if (i != max)
buffer->merge_clusters (i, max + 1);
}
/* Put syllable back in. */
for (unsigned int i = start; i < end; i++)
info[i].syllable() = syllable;
}
/* Setup masks now */
{
hb_mask_t mask;
/* Post-base */
mask = khmer_plan->mask_array[BLWF] | khmer_plan->mask_array[ABVF] | khmer_plan->mask_array[PSTF];
for (unsigned int i = base + 1; i < end; i++)
info[i].mask |= mask;
}
unsigned int pref_len = 2;
if (khmer_plan->mask_array[PREF] && base + pref_len < end)
{
/* Find a Halant,Ra sequence and mark it for pre-base-reordering processing. */
for (unsigned int i = base + 1; i + pref_len - 1 < end; i++) {
hb_codepoint_t glyphs[2];
for (unsigned int j = 0; j < pref_len; j++)
glyphs[j] = info[i + j].codepoint;
if (khmer_plan->pref.would_substitute (glyphs, pref_len, face))
{
for (unsigned int j = 0; j < pref_len; j++)
info[i++].mask |= khmer_plan->mask_array[PREF];
/* Mark the subsequent stuff with 'cfar'. Used in Khmer.
* Read the feature spec.
* This allows distinguishing the following cases with MS Khmer fonts:
* U+1784,U+17D2,U+179A,U+17D2,U+1782
* U+1784,U+17D2,U+1782,U+17D2,U+179A
*/
if (khmer_plan->mask_array[CFAR])
for (; i < end; i++)
info[i].mask |= khmer_plan->mask_array[CFAR];
break;
}
}
}
}
static void
initial_reordering_syllable (const hb_ot_shape_plan_t *plan,
hb_face_t *face,
hb_buffer_t *buffer,
unsigned int start, unsigned int end)
{
syllable_type_t syllable_type = (syllable_type_t) (buffer->info[start].syllable() & 0x0F);
switch (syllable_type)
{
case broken_cluster: /* We already inserted dotted-circles, so just call the consonant_syllable. */
case consonant_syllable:
initial_reordering_consonant_syllable (plan, face, buffer, start, end);
break;
case non_khmer_cluster:
break;
}
}
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_codepoint_t dottedcircle_glyph;
if (!font->get_nominal_glyph (0x25CCu, &dottedcircle_glyph))
return;
hb_glyph_info_t dottedcircle = {0};
dottedcircle.codepoint = 0x25CCu;
set_khmer_properties (dottedcircle);
dottedcircle.codepoint = dottedcircle_glyph;
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().khmer_category() == OT_Repha)
buffer->next_glyph ();
buffer->output_info (ginfo);
}
else
buffer->next_glyph ();
}
buffer->swap_buffers ();
}
static void
initial_reordering (const hb_ot_shape_plan_t *plan,
hb_font_t *font,
hb_buffer_t *buffer)
{
insert_dotted_circles (plan, font, buffer);
foreach_syllable (buffer, start, end)
initial_reordering_syllable (plan, font->face, buffer, start, end);
}
static void
final_reordering_syllable (const hb_ot_shape_plan_t *plan,
hb_buffer_t *buffer,
unsigned int start, unsigned int end)
{
const khmer_shape_plan_t *khmer_plan = (const khmer_shape_plan_t *) plan->data;
hb_glyph_info_t *info = buffer->info;
/* This function relies heavily on halant glyphs. Lots of ligation
* and possibly multiple substitutions happened prior to this
* phase, and that might have messed up our properties. Recover
* from a particular case of that where we're fairly sure that a
* class of OT_H is desired but has been lost. */
if (khmer_plan->virama_glyph)
{
unsigned int virama_glyph = khmer_plan->virama_glyph;
for (unsigned int i = start; i < end; i++)
if (info[i].codepoint == virama_glyph &&
_hb_glyph_info_ligated (&info[i]) &&
_hb_glyph_info_multiplied (&info[i]))
{
/* This will make sure that this glyph passes is_coeng() test. */
info[i].khmer_category() = OT_H;
_hb_glyph_info_clear_ligated_and_multiplied (&info[i]);
}
}
/* 4. Final reordering:
*
* After the localized forms and basic shaping forms GSUB features have been
* applied (see below), the shaping engine performs some final glyph
* reordering before applying all the remaining font features to the entire
* syllable.
*/
bool try_pref = !!khmer_plan->mask_array[PREF];
/* Find base again */
unsigned int base;
for (base = start; base < end; base++)
if (info[base].khmer_position() >= POS_BASE_C)
{
if (try_pref && base + 1 < end)
{
for (unsigned int i = base + 1; i < end; i++)
if ((info[i].mask & khmer_plan->mask_array[PREF]) != 0)
{
if (!(_hb_glyph_info_substituted (&info[i]) &&
_hb_glyph_info_ligated_and_didnt_multiply (&info[i])))
{
/* Ok, this was a 'pref' candidate but didn't form any.
* Base is around here... */
base = i;
while (base < end && is_coeng (info[base]))
base++;
info[base].khmer_position() = POS_BASE_C;
try_pref = false;
}
break;
}
}
if (start < base && info[base].khmer_position() > POS_BASE_C)
base--;
break;
}
if (base == end && start < base &&
is_one_of (info[base - 1], FLAG (OT_ZWJ)))
base--;
if (base < end)
while (start < base &&
is_one_of (info[base], (FLAG (OT_N) | FLAG (OT_Coeng))))
base--;
/* o Reorder matras:
*
* If a pre-base matra character had been reordered before applying basic
* features, the glyph can be moved closer to the main consonant based on
* whether half-forms had been formed. Actual position for the matra is
* defined as “after last standalone halant glyph, after initial matra
* position and before the main consonant”. If ZWJ or ZWNJ follow this
* halant, position is moved after it.
*/
if (start + 1 < end && start < base) /* Otherwise there can't be any pre-base matra characters. */
{
/* If we lost track of base, alas, position before last thingy. */
unsigned int new_pos = base == end ? base - 2 : base - 1;
while (new_pos > start &&
!(is_one_of (info[new_pos], (FLAG (OT_M) | FLAG (OT_Coeng)))))
new_pos--;
/* If we found no Halant we are done.
* Otherwise only proceed if the Halant does
* not belong to the Matra itself! */
if (is_coeng (info[new_pos]) &&
info[new_pos].khmer_position() != POS_PRE_M)
{
/* -> If ZWJ or ZWNJ follow this halant, position is moved after it. */
if (new_pos + 1 < end && is_joiner (info[new_pos + 1]))
new_pos++;
}
else
new_pos = start; /* No move. */
if (start < new_pos && info[new_pos].khmer_position () != POS_PRE_M)
{
/* Now go see if there's actually any matras... */
for (unsigned int i = new_pos; i > start; i--)
if (info[i - 1].khmer_position () == POS_PRE_M)
{
unsigned int old_pos = i - 1;
if (old_pos < base && base <= new_pos) /* Shouldn't actually happen. */
base--;
hb_glyph_info_t tmp = info[old_pos];
memmove (&info[old_pos], &info[old_pos + 1], (new_pos - old_pos) * sizeof (info[0]));
info[new_pos] = tmp;
/* Note: this merge_clusters() is intentionally *after* the reordering.
* Indic matra reordering is special and tricky... */
buffer->merge_clusters (new_pos, MIN (end, base + 1));
new_pos--;
}
} else {
for (unsigned int i = start; i < base; i++)
if (info[i].khmer_position () == POS_PRE_M) {
buffer->merge_clusters (i, MIN (end, base + 1));
break;
}
}
}
/* o Reorder pre-base-reordering consonants:
*
* If a pre-base-reordering consonant is found, reorder it according to
* the following rules:
*/
if (try_pref && base + 1 < end) /* Otherwise there can't be any pre-base-reordering Ra. */
{
for (unsigned int i = base + 1; i < end; i++)
if ((info[i].mask & khmer_plan->mask_array[PREF]) != 0)
{
/* 1. Only reorder a glyph produced by substitution during application
* of the <pref> feature. (Note that a font may shape a Ra consonant with
* the feature generally but block it in certain contexts.)
*/
/* Note: We just check that something got substituted. We don't check that
* the <pref> feature actually did it...
*
* Reorder pref only if it ligated. */
if (_hb_glyph_info_ligated_and_didnt_multiply (&info[i]))
{
/*
* 2. Try to find a target position the same way as for pre-base matra.
* If it is found, reorder pre-base consonant glyph.
*
* 3. If position is not found, reorder immediately before main
* consonant.
*/
unsigned int new_pos = base;
while (new_pos > start &&
!(is_one_of (info[new_pos - 1], FLAG(OT_M) | FLAG (OT_Coeng))))
new_pos--;
/* In Khmer coeng model, a H,Ra can go *after* matras. If it goes after a
* split matra, it should be reordered to *before* the left part of such matra. */
if (new_pos > start && info[new_pos - 1].khmer_category() == OT_M)
{
unsigned int old_pos = i;
for (unsigned int j = base + 1; j < old_pos; j++)
if (info[j].khmer_category() == OT_M)
{
new_pos--;
break;
}
}
if (new_pos > start && is_coeng (info[new_pos - 1]))
{
/* -> If ZWJ or ZWNJ follow this halant, position is moved after it. */
if (new_pos < end && is_joiner (info[new_pos]))
new_pos++;
}
{
unsigned int old_pos = i;
buffer->merge_clusters (new_pos, old_pos + 1);
hb_glyph_info_t tmp = info[old_pos];
memmove (&info[new_pos + 1], &info[new_pos], (old_pos - new_pos) * sizeof (info[0]));
info[new_pos] = tmp;
if (new_pos <= base && base < old_pos)
base++;
}
}
break;
}
}
/*
* Finish off the clusters and go home!
*/
if (hb_options ().uniscribe_bug_compatible)
{
/* Uniscribe merges the entire syllable into a single cluster... Except for Tamil & Sinhala.
* This means, half forms are submerged into the main consonant's cluster.
* This is unnecessary, and makes cursor positioning harder, but that's what
* Uniscribe does. */
buffer->merge_clusters (start, end);
}
}
static void
final_reordering (const hb_ot_shape_plan_t *plan,
hb_font_t *font HB_UNUSED,
hb_buffer_t *buffer)
{
unsigned int count = buffer->len;
if (unlikely (!count)) return;
foreach_syllable (buffer, start, end)
final_reordering_syllable (plan, buffer, start, end);
HB_BUFFER_DEALLOCATE_VAR (buffer, khmer_category);
HB_BUFFER_DEALLOCATE_VAR (buffer, khmer_position);
}
static void
clear_syllables (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;
unsigned int count = buffer->len;
for (unsigned int i = 0; i < count; i++)
info[i].syllable() = 0;
}
static bool
decompose_khmer (const hb_ot_shape_normalize_context_t *c,
hb_codepoint_t ab,
hb_codepoint_t *a,
hb_codepoint_t *b)
{
switch (ab)
{
/*
* Decompose split matras that don't have Unicode decompositions.
*/
/* Khmer */
case 0x17BEu : *a = 0x17C1u; *b= 0x17BEu; return true;
case 0x17BFu : *a = 0x17C1u; *b= 0x17BFu; return true;
case 0x17C0u : *a = 0x17C1u; *b= 0x17C0u; return true;
case 0x17C4u : *a = 0x17C1u; *b= 0x17C4u; return true;
case 0x17C5u : *a = 0x17C1u; *b= 0x17C5u; return true;
}
return (bool) c->unicode->decompose (ab, a, b);
}
static bool
compose_khmer (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_khmer =
{
collect_features_khmer,
override_features_khmer,
data_create_khmer,
data_destroy_khmer,
nullptr, /* preprocess_text */
nullptr, /* postprocess_glyphs */
HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
decompose_khmer,
compose_khmer,
setup_masks_khmer,
nullptr, /* disable_otl */
nullptr, /* reorder_marks */
HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
false, /* fallback_position */
};
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