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[khmer] Remove indic_config->reph_pos

This commit is contained in:
Behdad Esfahbod 2018-01-05 16:01:17 +00:00
parent ffcd6c7efd
commit c135324af1
1 changed files with 10 additions and 323 deletions
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323
src/hb-ot-shape-complex-khmer.cc
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@ -110,36 +110,6 @@ matra_position (hb_codepoint_t u, khmer_position_t side)
return side;
}
/* XXX
* This is a hack for now. We should move this data into the main Indic table.
* Or completely remove it and just check in the tables.
*/
static const hb_codepoint_t ra_chars[] = {
0x0930u, /* Devanagari */
0x09B0u, /* Bengali */
0x09F0u, /* Bengali */
0x0A30u, /* Gurmukhi */ /* No Reph */
0x0AB0u, /* Gujarati */
0x0B30u, /* Oriya */
0x0BB0u, /* Tamil */ /* No Reph */
0x0C30u, /* Telugu */ /* Reph formed only with ZWJ */
0x0CB0u, /* Kannada */
0x0D30u, /* Malayalam */ /* No Reph, Logical Repha */
0x0DBBu, /* Sinhala */ /* Reph formed only with ZWJ */
0x179Au, /* Khmer */ /* No Reph, Visual Repha */
};
static inline bool
is_ra (hb_codepoint_t u)
{
for (unsigned int i = 0; i < ARRAY_LENGTH (ra_chars); i++)
if (u == ra_chars[i])
return true;
return false;
}
static inline bool
is_one_of (const hb_glyph_info_t &info, unsigned int flags)
{
@ -240,7 +210,7 @@ set_khmer_properties (hb_glyph_info_t &info)
if ((FLAG_UNSAFE (cat) & CONSONANT_FLAGS))
{
pos = POS_BASE_C;
if (is_ra (u))
if (u == 0x179Au)
cat = OT_Ra;
}
else if (cat == OT_M)
@ -273,14 +243,6 @@ set_khmer_properties (hb_glyph_info_t &info)
* instead of adding a new flag in these structs.
*/
enum reph_position_t {
REPH_POS_AFTER_MAIN = POS_AFTER_MAIN,
REPH_POS_BEFORE_SUB = POS_BEFORE_SUB,
REPH_POS_AFTER_SUB = POS_AFTER_SUB,
REPH_POS_BEFORE_POST = POS_BEFORE_POST,
REPH_POS_AFTER_POST = POS_AFTER_POST,
REPH_POS_DONT_CARE = POS_RA_TO_BECOME_REPH
};
enum reph_mode_t {
REPH_MODE_IMPLICIT, /* Reph formed out of initial Ra,H sequence. */
REPH_MODE_EXPLICIT, /* Reph formed out of initial Ra,H,ZWJ sequence. */
@ -293,14 +255,13 @@ enum blwf_mode_t {
};
struct indic_config_t
{
reph_position_t reph_pos;
reph_mode_t reph_mode;
blwf_mode_t blwf_mode;
};
static const indic_config_t indic_configs[] =
{
{REPH_POS_DONT_CARE, REPH_MODE_VIS_REPHA,BLWF_MODE_PRE_AND_POST},
{REPH_MODE_VIS_REPHA,BLWF_MODE_PRE_AND_POST},
};
@ -590,120 +551,17 @@ initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan,
const khmer_shape_plan_t *khmer_plan = (const khmer_shape_plan_t *) plan->data;
hb_glyph_info_t *info = buffer->info;
/* 1. Find base consonant:
*
* The shaping engine finds the base consonant of the syllable, using the
* following algorithm: starting from the end of the syllable, move backwards
* until a consonant is found that does not have a below-base or post-base
* form (post-base forms have to follow below-base forms), or that is not a
* pre-base-reordering Ra, or arrive at the first consonant. The consonant
* stopped at will be the base.
*
* o If the syllable starts with Ra + Halant (in a script that has Reph)
* and has more than one consonant, Ra is excluded from candidates for
* base consonants.
*/
unsigned int base = end;
bool has_reph = false;
{
/* -> If the syllable starts with Ra + Halant (in a script that has Reph)
* and has more than one consonant, Ra is excluded from candidates for
* base consonants. */
unsigned int limit = start;
if (khmer_plan->config->reph_pos != REPH_POS_DONT_CARE &&
khmer_plan->mask_array[RPHF] &&
start + 3 <= end &&
(
(khmer_plan->config->reph_mode == REPH_MODE_IMPLICIT && !is_joiner (info[start + 2])) ||
(khmer_plan->config->reph_mode == REPH_MODE_EXPLICIT && info[start + 2].khmer_category() == OT_ZWJ)
))
{
/* See if it matches the 'rphf' feature. */
hb_codepoint_t glyphs[3] = {info[start].codepoint,
info[start + 1].codepoint,
khmer_plan->config->reph_mode == REPH_MODE_EXPLICIT ?
info[start + 2].codepoint : 0};
if (khmer_plan->rphf.would_substitute (glyphs, 2, face) ||
(khmer_plan->config->reph_mode == REPH_MODE_EXPLICIT &&
khmer_plan->rphf.would_substitute (glyphs, 3, face)))
{
limit += 2;
while (limit < end && is_joiner (info[limit]))
limit++;
base = start;
has_reph = true;
}
} else if (khmer_plan->config->reph_mode == REPH_MODE_LOG_REPHA && info[start].khmer_category() == OT_Repha)
{
limit += 1;
while (limit < end && is_joiner (info[limit]))
limit++;
base = start;
has_reph = true;
}
/* 1. Khmer shaping assumes that a syllable will begin with a Cons, IndV, or Number. */
/* The first consonant is always the base. */
base = start;
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;
/* -> If the syllable starts with Ra + Halant (in a script that has Reph)
* and has more than one consonant, Ra is excluded from candidates for
* base consonants.
*
* Only do this for unforced Reph. (ie. not for Ra,H,ZWJ. */
if (has_reph && base == start && limit - base <= 2) {
/* Have no other consonant, so Reph is not formed and Ra becomes base. */
has_reph = false;
}
}
/* 2. Decompose and reorder Matras:
*
* Each matra and any syllable modifier sign in the syllable are moved to the
* appropriate position relative to the consonant(s) in the syllable. The
* shaping engine decomposes two- or three-part matras into their constituent
* parts before any repositioning. Matra characters are classified by which
* consonant in a conjunct they have affinity for and are reordered to the
* following positions:
*
* o Before first half form in the syllable
* o After subjoined consonants
* o After post-form consonant
* o After main consonant (for above marks)
*
* IMPLEMENTATION NOTES:
*
* The normalize() routine has already decomposed matras for us, so we don't
* need to worry about that.
*/
/* 3. Reorder marks to canonical order:
*
* Adjacent nukta and halant or nukta and vedic sign are always repositioned
* if necessary, so that the nukta is first.
*
* IMPLEMENTATION NOTES:
*
* We don't need to do this: the normalize() routine already did this for us.
*/
/* Reorder characters */
for (unsigned int i = start; i < base; i++)
info[i].khmer_position() = MIN (POS_PRE_C, (khmer_position_t) info[i].khmer_position());
if (base < end)
info[base].khmer_position() = POS_BASE_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++)
@ -716,10 +574,6 @@ initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan,
break;
}
/* Handle beginning Ra */
if (has_reph)
info[start].khmer_position() = POS_RA_TO_BECOME_REPH;
/* Attach misc marks to previous char to move with them. */
{
khmer_position_t last_pos = POS_START;
@ -766,7 +620,6 @@ initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan,
last = i;
}
{
/* Use syllable() for sort accounting temporarily. */
unsigned int syllable = info[start].syllable();
@ -811,20 +664,6 @@ initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan,
{
hb_mask_t mask;
/* Reph */
for (unsigned int i = start; i < end && info[i].khmer_position() == POS_RA_TO_BECOME_REPH; i++)
info[i].mask |= khmer_plan->mask_array[RPHF];
/* Pre-base */
mask = khmer_plan->mask_array[HALF];
if (khmer_plan->config->blwf_mode == BLWF_MODE_PRE_AND_POST)
mask |= khmer_plan->mask_array[BLWF];
for (unsigned int i = start; i < base; i++)
info[i].mask |= mask;
/* Base */
mask = 0;
if (base < end)
info[base].mask |= 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++)
@ -1138,158 +977,6 @@ final_reordering_syllable (const hb_ot_shape_plan_t *plan,
}
/* o Reorder reph:
*
* Reph’s original position is always at the beginning of the syllable,
* (i.e. it is not reordered at the character reordering stage). However,
* it will be reordered according to the basic-forms shaping results.
* Possible positions for reph, depending on the script, are; after main,
* before post-base consonant forms, and after post-base consonant forms.
*/
/* Two cases:
*
* - If repha is encoded as a sequence of characters (Ra,H or Ra,H,ZWJ), then
* we should only move it if the sequence ligated to the repha form.
*
* - If repha is encoded separately and in the logical position, we should only
* move it if it did NOT ligate. If it ligated, it's probably the font trying
* to make it work without the reordering.
*/
if (start + 1 < end &&
info[start].khmer_position() == POS_RA_TO_BECOME_REPH &&
((info[start].khmer_category() == OT_Repha) ^
_hb_glyph_info_ligated_and_didnt_multiply (&info[start])))
{
unsigned int new_reph_pos;
reph_position_t reph_pos = khmer_plan->config->reph_pos;
assert (reph_pos != REPH_POS_DONT_CARE);
/* 1. If reph should be positioned after post-base consonant forms,
* proceed to step 5.
*/
if (reph_pos == REPH_POS_AFTER_POST)
{
goto reph_step_5;
}
/* 2. If the reph repositioning class is not after post-base: target
* position is after the first explicit halant glyph between the
* first post-reph consonant and last main consonant. If ZWJ or ZWNJ
* are following this halant, position is moved after it. If such
* position is found, this is the target position. Otherwise,
* proceed to the next step.
*
* Note: in old-implementation fonts, where classifications were
* fixed in shaping engine, there was no case where reph position
* will be found on this step.
*/
{
new_reph_pos = start + 1;
while (new_reph_pos < base && !is_coeng (info[new_reph_pos]))
new_reph_pos++;
if (new_reph_pos < base && is_coeng (info[new_reph_pos]))
{
/* ->If ZWJ or ZWNJ are following this halant, position is moved after it. */
if (new_reph_pos + 1 < base && is_joiner (info[new_reph_pos + 1]))
new_reph_pos++;
goto reph_move;
}
}
/* 3. If reph should be repositioned after the main consonant: find the
* first consonant not ligated with main, or find the first
* consonant that is not a potential pre-base-reordering Ra.
*/
if (reph_pos == REPH_POS_AFTER_MAIN)
{
new_reph_pos = base;
while (new_reph_pos + 1 < end && info[new_reph_pos + 1].khmer_position() <= POS_AFTER_MAIN)
new_reph_pos++;
if (new_reph_pos < end)
goto reph_move;
}
/* 4. If reph should be positioned before post-base consonant, find
* first post-base classified consonant not ligated with main. If no
* consonant is found, the target position should be before the
* first matra, syllable modifier sign or vedic sign.
*/
/* This is our take on what step 4 is trying to say (and failing, BADLY). */
if (reph_pos == REPH_POS_AFTER_SUB)
{
new_reph_pos = base;
while (new_reph_pos + 1 < end &&
!( FLAG_UNSAFE (info[new_reph_pos + 1].khmer_position()) & (FLAG (POS_POST_C) | FLAG (POS_AFTER_POST) | FLAG (POS_SMVD))))
new_reph_pos++;
if (new_reph_pos < end)
goto reph_move;
}
/* 5. If no consonant is found in steps 3 or 4, move reph to a position
* immediately before the first post-base matra, syllable modifier
* sign or vedic sign that has a reordering class after the intended
* reph position. For example, if the reordering position for reph
* is post-main, it will skip above-base matras that also have a
* post-main position.
*/
reph_step_5:
{
/* Copied from step 2. */
new_reph_pos = start + 1;
while (new_reph_pos < base && !is_coeng (info[new_reph_pos]))
new_reph_pos++;
if (new_reph_pos < base && is_coeng (info[new_reph_pos]))
{
/* ->If ZWJ or ZWNJ are following this halant, position is moved after it. */
if (new_reph_pos + 1 < base && is_joiner (info[new_reph_pos + 1]))
new_reph_pos++;
goto reph_move;
}
}
/* 6. Otherwise, reorder reph to the end of the syllable.
*/
{
new_reph_pos = end - 1;
while (new_reph_pos > start && info[new_reph_pos].khmer_position() == POS_SMVD)
new_reph_pos--;
/*
* If the Reph is to be ending up after a Matra,Halant sequence,
* position it before that Halant so it can interact with the Matra.
* However, if it's a plain Consonant,Halant we shouldn't do that.
* Uniscribe doesn't do this.
* TEST: U+0930,U+094D,U+0915,U+094B,U+094D
*/
if (!hb_options ().uniscribe_bug_compatible &&
unlikely (is_coeng (info[new_reph_pos]))) {
for (unsigned int i = base + 1; i < new_reph_pos; i++)
if (info[i].khmer_category() == OT_M) {
/* Ok, got it. */
new_reph_pos--;
}
}
goto reph_move;
}
reph_move:
{
/* Move */
buffer->merge_clusters (start, new_reph_pos + 1);
hb_glyph_info_t reph = info[start];
memmove (&info[start], &info[start + 1], (new_reph_pos - start) * sizeof (info[0]));
info[new_reph_pos] = reph;
if (start < base && base <= new_reph_pos)
base--;
}
}
/* o Reorder pre-base-reordering consonants:
*
* If a pre-base-reordering consonant is found, reorder it according to