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[Indic] Add per-script configuration tables

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This concludes the Indic shape_plan work.  May do for Arabic also...
pull/1/head
Behdad Esfahbod 12 years ago
parent 85fc6c483f
commit 11b0e20ba4
2 changed files with 159 additions and 166 deletions
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  1. 16
      src/hb-ot-shape-complex-indic-private.hh
  2. 309
      src/hb-ot-shape-complex-indic.cc

16
src/hb-ot-shape-complex-indic-private.hh
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@ -157,8 +157,8 @@ enum indic_matra_category_t {
#define IS_DEVA(u) (IN_HALF_BLOCK (u, 0x0900))
#define IS_BENG(u) (IN_HALF_BLOCK (u, 0x0980))
#define IS_GURM(u) (IN_HALF_BLOCK (u, 0x0A00))
#define IS_GUJA(u) (IN_HALF_BLOCK (u, 0x0A80))
#define IS_GURU(u) (IN_HALF_BLOCK (u, 0x0A00))
#define IS_GUJR(u) (IN_HALF_BLOCK (u, 0x0A80))
#define IS_ORYA(u) (IN_HALF_BLOCK (u, 0x0B00))
#define IS_TAML(u) (IN_HALF_BLOCK (u, 0x0B80))
#define IS_TELU(u) (IN_HALF_BLOCK (u, 0x0C00))
@ -172,8 +172,8 @@ enum indic_matra_category_t {
#define MATRA_POS_RIGHT(u) ( \
IS_DEVA(u) ? POS_AFTER_SUB : \
IS_BENG(u) ? POS_AFTER_POST : \
IS_GURM(u) ? POS_AFTER_POST : \
IS_GUJA(u) ? POS_AFTER_POST : \
IS_GURU(u) ? POS_AFTER_POST : \
IS_GUJR(u) ? POS_AFTER_POST : \
IS_ORYA(u) ? POS_AFTER_POST : \
IS_TAML(u) ? POS_AFTER_POST : \
IS_TELU(u) ? (u <= 0x0C42 ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
@ -185,8 +185,8 @@ enum indic_matra_category_t {
)
#define MATRA_POS_TOP(u) ( /* BENG and MLYM don't have top matras. */ \
IS_DEVA(u) ? POS_AFTER_SUB : \
IS_GURM(u) ? POS_AFTER_POST : /* Deviate from spec */ \
IS_GUJA(u) ? POS_AFTER_SUB : \
IS_GURU(u) ? POS_AFTER_POST : /* Deviate from spec */ \
IS_GUJR(u) ? POS_AFTER_SUB : \
IS_ORYA(u) ? POS_AFTER_MAIN : \
IS_TAML(u) ? POS_AFTER_SUB : \
IS_TELU(u) ? POS_BEFORE_SUB : \
@ -198,8 +198,8 @@ enum indic_matra_category_t {
#define MATRA_POS_BOTTOM(u) ( \
IS_DEVA(u) ? POS_AFTER_SUB : \
IS_BENG(u) ? POS_AFTER_SUB : \
IS_GURM(u) ? POS_AFTER_POST : \
IS_GUJA(u) ? POS_AFTER_POST : \
IS_GURU(u) ? POS_AFTER_POST : \
IS_GUJR(u) ? POS_AFTER_POST : \
IS_ORYA(u) ? POS_AFTER_SUB : \
IS_TAML(u) ? POS_AFTER_POST : \
IS_TELU(u) ? POS_BEFORE_SUB : \

309
src/hb-ot-shape-complex-indic.cc
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@ -25,23 +25,12 @@
*/
#include "hb-ot-shape-complex-indic-private.hh"
#include "hb-ot-shape-private.hh"
#include "hb-ot-layout-private.hh"
#define OLD_INDIC_TAG(script) (((hb_tag_t) script) | 0x20000000)
#define IS_OLD_INDIC_TAG(tag) ( \
(tag) == OLD_INDIC_TAG (HB_SCRIPT_BENGALI) || \
(tag) == OLD_INDIC_TAG (HB_SCRIPT_DEVANAGARI) || \
(tag) == OLD_INDIC_TAG (HB_SCRIPT_GUJARATI) || \
(tag) == OLD_INDIC_TAG (HB_SCRIPT_GURMUKHI) || \
(tag) == OLD_INDIC_TAG (HB_SCRIPT_KANNADA) || \
(tag) == OLD_INDIC_TAG (HB_SCRIPT_MALAYALAM) || \
(tag) == OLD_INDIC_TAG (HB_SCRIPT_ORIYA) || \
(tag) == OLD_INDIC_TAG (HB_SCRIPT_TAMIL) || \
(tag) == OLD_INDIC_TAG (HB_SCRIPT_TELUGU) || \
0)
/*
* Global Indic shaper options.
*/
struct indic_options_t
{
@ -82,6 +71,65 @@ indic_options (void)
}
/*
* Indic configurations. Note that we do not want to keep every single script-specific
* behavior in these tables necessarily. This should mainly be used for per-script
* properties that are cheaper keeping here, than in the code. Ie. if, say, one and
* only one script has an exception, that one script can be if'ed directly in the code,
* instead of adding a new flag in these structs.
*/
enum base_position_t {
BASE_POS_FIRST,
BASE_POS_LAST
};
enum reph_position_t {
REPH_POS_DEFAULT = POS_BEFORE_POST,
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
};
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. */
REPH_MODE_VIS_REPHA, /* Encoded Repha character, no reordering needed. */
REPH_MODE_LOG_REPHA /* Encoded Repha character, needs reordering. */
};
struct indic_config_t
{
hb_script_t script;
bool has_old_spec;
hb_codepoint_t virama;
base_position_t base_pos;
reph_position_t reph_pos;
reph_mode_t reph_mode;
};
static const indic_config_t indic_configs[] =
{
/* Default. Should be first. */
{HB_SCRIPT_INVALID, false, 0,BASE_POS_LAST, REPH_POS_DEFAULT, REPH_MODE_IMPLICIT},
{HB_SCRIPT_DEVANAGARI,true, 0x094D,BASE_POS_LAST, REPH_POS_BEFORE_POST,REPH_MODE_IMPLICIT},
{HB_SCRIPT_BENGALI, true, 0x09CD,BASE_POS_LAST, REPH_POS_AFTER_SUB, REPH_MODE_IMPLICIT},
{HB_SCRIPT_GURMUKHI, true, 0x0A4D,BASE_POS_LAST, REPH_POS_BEFORE_SUB, REPH_MODE_IMPLICIT},
{HB_SCRIPT_GUJARATI, true, 0x0ACD,BASE_POS_LAST, REPH_POS_BEFORE_POST,REPH_MODE_IMPLICIT},
{HB_SCRIPT_ORIYA, true, 0x0B4D,BASE_POS_LAST, REPH_POS_AFTER_MAIN, REPH_MODE_IMPLICIT},
{HB_SCRIPT_TAMIL, true, 0x0BCD,BASE_POS_LAST, REPH_POS_AFTER_POST, REPH_MODE_IMPLICIT},
{HB_SCRIPT_TELUGU, true, 0x0C4D,BASE_POS_LAST, REPH_POS_AFTER_POST, REPH_MODE_EXPLICIT},
{HB_SCRIPT_KANNADA, true, 0x0CCD,BASE_POS_LAST, REPH_POS_AFTER_POST, REPH_MODE_IMPLICIT},
{HB_SCRIPT_MALAYALAM, true, 0x0D4D,BASE_POS_LAST, REPH_POS_AFTER_MAIN, REPH_MODE_LOG_REPHA},
{HB_SCRIPT_SINHALA, false,0x0DCA,BASE_POS_FIRST,REPH_POS_AFTER_MAIN, REPH_MODE_EXPLICIT},
{HB_SCRIPT_KHMER, false,0x17D2,BASE_POS_FIRST,REPH_POS_DEFAULT, REPH_MODE_VIS_REPHA},
};
/*
* Indic shaper.
*/
struct feature_list_t {
hb_tag_t tag;
@ -228,7 +276,7 @@ struct indic_shape_plan_t
hb_codepoint_t glyph = virama_glyph;
if (unlikely (virama_glyph == (hb_codepoint_t) -1))
{
if (!font->get_glyph (virama, 0, &glyph))
if (!config->virama || !font->get_glyph (config->virama, 0, &glyph))
glyph = 0;
/* Technically speaking, the spec says we should apply 'locl' to virama too.
* Maybe one day... */
@ -242,10 +290,9 @@ struct indic_shape_plan_t
return glyph != 0;
}
const indic_config_t *config;
bool is_old_spec;
hb_codepoint_t virama;
hb_codepoint_t virama_glyph;
would_substitute_feature_t pref;
@ -262,26 +309,15 @@ data_create_indic (const hb_ot_shape_plan_t *plan)
if (unlikely (!indic_plan))
return NULL;
indic_plan->is_old_spec = IS_OLD_INDIC_TAG (plan->map.get_chosen_script (0));
{
hb_codepoint_t virama;
switch ((int) plan->props.script) {
case HB_SCRIPT_DEVANAGARI:virama = 0x094D; break;
case HB_SCRIPT_BENGALI: virama = 0x09CD; break;
case HB_SCRIPT_GURMUKHI: virama = 0x0A4D; break;
case HB_SCRIPT_GUJARATI: virama = 0x0ACD; break;
case HB_SCRIPT_ORIYA: virama = 0x0B4D; break;
case HB_SCRIPT_TAMIL: virama = 0x0BCD; break;
case HB_SCRIPT_TELUGU: virama = 0x0C4D; break;
case HB_SCRIPT_KANNADA: virama = 0x0CCD; break;
case HB_SCRIPT_MALAYALAM: virama = 0x0D4D; break;
case HB_SCRIPT_SINHALA: virama = 0x0DCA; break;
case HB_SCRIPT_KHMER: virama = 0x17D2; break;
default: virama = 0; break;
indic_plan->config = &indic_configs[0];
for (unsigned int i = 1; i < ARRAY_LENGTH (indic_configs); i++)
if (plan->props.script == indic_configs[i].script) {
indic_plan->config = &indic_configs[i];
break;
}
indic_plan->virama = virama;
}
indic_plan->virama_glyph = indic_plan->virama ? (hb_codepoint_t) -1 : 0;
indic_plan->is_old_spec = indic_plan->config->has_old_spec && ((plan->map.get_chosen_script (0) & 0x000000FF) != '2');
indic_plan->virama_glyph = (hb_codepoint_t) -1;
indic_plan->pref.init (&plan->map, HB_TAG('p','r','e','f'));
indic_plan->blwf.init (&plan->map, HB_TAG('b','l','w','f'));
@ -397,9 +433,9 @@ initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan, hb_buffer
start + 3 <= end &&
info[start].indic_category() == OT_Ra &&
info[start + 1].indic_category() == OT_H &&
(unlikely (buffer->props.script == HB_SCRIPT_SINHALA || buffer->props.script == HB_SCRIPT_TELUGU) ?
info[start + 2].indic_category() == OT_ZWJ /* In Sinhala & Telugu, form Reph only if ZWJ is present */:
!is_joiner (info[start + 2] /* In other scripts, any joiner blocks Reph formation */ )
(/* TODO Handle other Reph modes. */
(indic_plan->config->reph_mode == REPH_MODE_IMPLICIT && !is_joiner (info[start + 2])) ||
(indic_plan->config->reph_mode == REPH_MODE_EXPLICIT && info[start + 2].indic_category() == OT_ZWJ)
))
{
limit += 2;
@ -409,92 +445,84 @@ initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan, hb_buffer
has_reph = true;
};
enum base_position_t {
BASE_FIRST,
BASE_LAST
} base_pos;
switch ((hb_tag_t) buffer->props.script)
{
case HB_SCRIPT_SINHALA:
case HB_SCRIPT_KHMER:
base_pos = BASE_FIRST;
break;
default:
base_pos = BASE_LAST;
break;
}
if (base_pos == BASE_LAST)
switch (indic_plan->config->base_pos == BASE_POS_LAST)
{
/* -> starting from the end of the syllable, move backwards */
unsigned int i = end;
bool seen_below = false;
do {
i--;
/* -> until a consonant is found */
if (is_consonant (info[i]))
{
/* -> that does not have a below-base or post-base form
* (post-base forms have to follow below-base forms), */
if (info[i].indic_position() != POS_BELOW_C &&
(info[i].indic_position() != POS_POST_C || seen_below))
case BASE_POS_LAST:
{
/* -> starting from the end of the syllable, move backwards */
unsigned int i = end;
bool seen_below = false;
do {
i--;
/* -> until a consonant is found */
if (is_consonant (info[i]))
{
/* -> that does not have a below-base or post-base form
* (post-base forms have to follow below-base forms), */
if (info[i].indic_position() != POS_BELOW_C &&
(info[i].indic_position() != POS_POST_C || seen_below))
{
base = i;
break;
}
if (info[i].indic_position() == POS_BELOW_C)
seen_below = true;
/* -> or that is not a pre-base reordering Ra,
*
* IMPLEMENTATION NOTES:
*
* Our pre-base reordering Ra's are marked POS_BELOW, so will be skipped
* by the logic above already.
*/
/* -> or arrive at the first consonant. The consonant stopped at will
* be the base. */
base = i;
break;
}
if (info[i].indic_position() == POS_BELOW_C)
seen_below = true;
else
{
/* A ZWJ after a Halant stops the base search, and requests an explicit
* half form.
* A ZWJ before a Halant, requests a subjoined form instead, and hence
* search continues. This is particularly important for Bengali
* sequence Ra,H,Ya that shouls form Ya-Phalaa by subjoining Ya. */
if (start < i &&
info[i].indic_category() == OT_ZWJ &&
info[i - 1].indic_category() == OT_H)
break;
}
} while (i > limit);
}
break;
/* -> or that is not a pre-base reordering Ra,
*
* IMPLEMENTATION NOTES:
*
* Our pre-base reordering Ra's are marked POS_BELOW, so will be skipped
* by the logic above already.
*/
case BASE_POS_FIRST:
{
/* In scripts without half forms (eg. Khmer), the first consonant is always the base. */
/* -> or arrive at the first consonant. The consonant stopped at will
* be the base. */
base = i;
}
else
{
/* A ZWJ after a Halant stops the base search, and requests an explicit
* half form.
* A ZWJ before a Halant, requests a subjoined form instead, and hence
* search continues. This is particularly important for Bengali
* sequence Ra,H,Ya that shouls form Ya-Phalaa by subjoining Ya. */
if (start < i &&
info[i].indic_category() == OT_ZWJ &&
info[i - 1].indic_category() == OT_H)
break;
}
} while (i > limit);
}
else
{
/* In scripts without half forms (eg. Khmer), the first consonant is always the base. */
if (!has_reph)
base = limit;
if (!has_reph)
base = limit;
/* Find the last base consonant that is not blocked by ZWJ. If there is
* a ZWJ right before a base consonant, that would request a subjoined form. */
for (unsigned int i = limit; i < end; i++)
if (is_consonant (info[i]) && info[i].indic_position() == POS_BASE_C)
{
if (limit < i && info[i - 1].indic_category() == OT_ZWJ)
break;
else
base = i;
}
/* Find the last base consonant that is not blocked by ZWJ. If there is
* a ZWJ right before a base consonant, that would request a subjoined form. */
for (unsigned int i = limit; i < end; i++)
if (is_consonant (info[i]) && info[i].indic_position() == POS_BASE_C)
{
if (limit < i && info[i - 1].indic_category() == OT_ZWJ)
break;
else
base = i;
}
/* Mark all subsequent consonants as below. */
for (unsigned int i = base + 1; i < end; i++)
if (is_consonant (info[i]) && info[i].indic_position() == POS_BASE_C)
info[i].indic_position() = POS_BELOW_C;
}
break;
/* Mark all subsequent consonants as below. */
for (unsigned int i = base + 1; i < end; i++)
if (is_consonant (info[i]) && info[i].indic_position() == POS_BASE_C)
info[i].indic_position() = POS_BELOW_C;
default:
abort ();
}
/* -> If the syllable starts with Ra + Halant (in a script that has Reph)
@ -864,50 +892,15 @@ final_reordering_syllable (const hb_ot_shape_plan_t *plan,
info[start].indic_position() == POS_RA_TO_BECOME_REPH &&
info[start + 1].indic_position() != POS_RA_TO_BECOME_REPH)
{
unsigned int new_reph_pos;
enum reph_position_t {
REPH_AFTER_MAIN,
REPH_BEFORE_SUBSCRIPT,
REPH_AFTER_SUBSCRIPT,
REPH_BEFORE_POSTSCRIPT,
REPH_AFTER_POSTSCRIPT
} reph_pos;
/* XXX Figure out old behavior too */
switch ((hb_tag_t) buffer->props.script)
{
case HB_SCRIPT_MALAYALAM:
case HB_SCRIPT_ORIYA:
case HB_SCRIPT_SINHALA:
reph_pos = REPH_AFTER_MAIN;
break;
case HB_SCRIPT_GURMUKHI:
reph_pos = REPH_BEFORE_SUBSCRIPT;
break;
case HB_SCRIPT_BENGALI:
reph_pos = REPH_AFTER_SUBSCRIPT;
break;
default:
case HB_SCRIPT_DEVANAGARI:
case HB_SCRIPT_GUJARATI:
reph_pos = REPH_BEFORE_POSTSCRIPT;
break;
case HB_SCRIPT_KANNADA:
case HB_SCRIPT_TAMIL:
case HB_SCRIPT_TELUGU:
reph_pos = REPH_AFTER_POSTSCRIPT;
break;
}
unsigned int new_reph_pos;
reph_position_t reph_pos = indic_plan->config->reph_pos;
/* XXX Figure out old behavior too */
/* 1. If reph should be positioned after post-base consonant forms,
* proceed to step 5.
*/
if (reph_pos == REPH_AFTER_POSTSCRIPT)
if (reph_pos == REPH_POS_AFTER_POST)
{
goto reph_step_5;
}
@ -940,7 +933,7 @@ final_reordering_syllable (const hb_ot_shape_plan_t *plan,
* first consonant not ligated with main, or find the first
* consonant that is not a potential pre-base reordering Ra.
*/
if (reph_pos == REPH_AFTER_MAIN)
if (reph_pos == REPH_POS_AFTER_MAIN)
{
new_reph_pos = base;
/* XXX Skip potential pre-base reordering Ra. */
@ -956,7 +949,7 @@ final_reordering_syllable (const hb_ot_shape_plan_t *plan,
* 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_AFTER_SUBSCRIPT)
if (reph_pos == REPH_POS_AFTER_SUB)
{
new_reph_pos = base;
while (new_reph_pos < end &&

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