harfbuzz/src/hb-ot-shape-complex-private.hh
Behdad Esfahbod 127daf15e0 Arabic mark width-zeroing regression
Mozilla Bug 873902 - Display Arabic text with diacritics is bad
https://bugzilla.mozilla.org/show_bug.cgi?id=873902
2013-05-20 09:11:35 -04:00

358 lines
10 KiB
C++

/*
* Copyright © 2010,2011,2012 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
*/
#ifndef HB_OT_SHAPE_COMPLEX_PRIVATE_HH
#define HB_OT_SHAPE_COMPLEX_PRIVATE_HH
#include "hb-private.hh"
#include "hb-ot-shape-private.hh"
#include "hb-ot-shape-normalize-private.hh"
/* buffer var allocations, used by complex shapers */
#define complex_var_u8_0() var2.u8[2]
#define complex_var_u8_1() var2.u8[3]
enum hb_ot_shape_zero_width_marks_type_t {
HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
// HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_EARLY,
HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE,
HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE
};
/* Master OT shaper list */
#define HB_COMPLEX_SHAPERS_IMPLEMENT_SHAPERS \
HB_COMPLEX_SHAPER_IMPLEMENT (default) /* should be first */ \
HB_COMPLEX_SHAPER_IMPLEMENT (arabic) \
HB_COMPLEX_SHAPER_IMPLEMENT (indic) \
HB_COMPLEX_SHAPER_IMPLEMENT (myanmar) \
HB_COMPLEX_SHAPER_IMPLEMENT (sea) \
HB_COMPLEX_SHAPER_IMPLEMENT (thai) \
/* ^--- Add new shapers here */
struct hb_ot_complex_shaper_t
{
char name[8];
/* collect_features()
* Called during shape_plan().
* Shapers should use plan->map to add their features and callbacks.
* May be NULL.
*/
void (*collect_features) (hb_ot_shape_planner_t *plan);
/* override_features()
* Called during shape_plan().
* Shapers should use plan->map to override features and add callbacks after
* common features are added.
* May be NULL.
*/
void (*override_features) (hb_ot_shape_planner_t *plan);
/* data_create()
* Called at the end of shape_plan().
* Whatever shapers return will be accessible through plan->data later.
* If NULL is returned, means a plan failure.
*/
void *(*data_create) (const hb_ot_shape_plan_t *plan);
/* data_destroy()
* Called when the shape_plan is being destroyed.
* plan->data is passed here for destruction.
* If NULL is returned, means a plan failure.
* May be NULL.
*/
void (*data_destroy) (void *data);
/* preprocess_text()
* Called during shape().
* Shapers can use to modify text before shaping starts.
* May be NULL.
*/
void (*preprocess_text) (const hb_ot_shape_plan_t *plan,
hb_buffer_t *buffer,
hb_font_t *font);
/* normalization_preference()
* Called during shape().
* May be NULL.
*/
hb_ot_shape_normalization_mode_t
(*normalization_preference) (const hb_segment_properties_t *props);
/* decompose()
* Called during shape()'s normalization.
* May be NULL.
*/
bool (*decompose) (const hb_ot_shape_normalize_context_t *c,
hb_codepoint_t ab,
hb_codepoint_t *a,
hb_codepoint_t *b);
/* compose()
* Called during shape()'s normalization.
* May be NULL.
*/
bool (*compose) (const hb_ot_shape_normalize_context_t *c,
hb_codepoint_t a,
hb_codepoint_t b,
hb_codepoint_t *ab);
/* setup_masks()
* Called during shape().
* Shapers should use map to get feature masks and set on buffer.
* Shapers may NOT modify characters.
* May be NULL.
*/
void (*setup_masks) (const hb_ot_shape_plan_t *plan,
hb_buffer_t *buffer,
hb_font_t *font);
hb_ot_shape_zero_width_marks_type_t zero_width_marks;
bool fallback_position;
};
#define HB_COMPLEX_SHAPER_IMPLEMENT(name) extern HB_INTERNAL const hb_ot_complex_shaper_t _hb_ot_complex_shaper_##name;
HB_COMPLEX_SHAPERS_IMPLEMENT_SHAPERS
#undef HB_COMPLEX_SHAPER_IMPLEMENT
static inline const hb_ot_complex_shaper_t *
hb_ot_shape_complex_categorize (const hb_ot_shape_planner_t *planner)
{
switch ((hb_tag_t) planner->props.script)
{
default:
return &_hb_ot_complex_shaper_default;
/* Unicode-1.1 additions */
case HB_SCRIPT_ARABIC:
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:
/* For Arabic script, use the Arabic shaper even if no OT script tag was found.
* This is because we do fallback shaping for Arabic script (and not others). */
if (planner->map.chosen_script[0] != HB_OT_TAG_DEFAULT_SCRIPT ||
planner->props.script == HB_SCRIPT_ARABIC)
return &_hb_ot_complex_shaper_arabic;
else
return &_hb_ot_complex_shaper_default;
/* Unicode-1.1 additions */
case HB_SCRIPT_THAI:
case HB_SCRIPT_LAO:
return &_hb_ot_complex_shaper_thai;
#if 0
/* Note:
* Currently we don't have a separate Hangul shaper. The default shaper handles
* Hangul by enabling jamo features. We may want to implement a separate shaper
* in the future. See this thread for details of what such a shaper would do:
*
* http://lists.freedesktop.org/archives/harfbuzz/2013-April/003070.html
*/
/* Unicode-1.1 additions */
case HB_SCRIPT_HANGUL:
return &_hb_ot_complex_shaper_hangul;
#endif
/* ^--- Add new shapers here */
#if 0
/* Note:
*
* These disabled scripts are listed in ucd/IndicSyllabicCategory.txt, but according
* to Martin Hosken and Jonathan Kew do not require complex shaping.
*
* TODO We should automate figuring out which scripts do not need complex shaping
*
* TODO We currently keep data for these scripts in our indic table. Need to fix the
* generator to not do that.
*/
/* Simple? */
/* Unicode-3.2 additions */
case HB_SCRIPT_BUHID:
case HB_SCRIPT_HANUNOO:
/* Unicode-5.1 additions */
case HB_SCRIPT_SAURASHTRA:
/* Unicode-6.0 additions */
case HB_SCRIPT_BATAK:
case HB_SCRIPT_BRAHMI:
/* Simple */
/* Unicode-1.1 additions */
/* These have their own shaper now. */
case HB_SCRIPT_LAO:
case HB_SCRIPT_THAI:
/* Unicode-2.0 additions */
case HB_SCRIPT_TIBETAN:
/* Unicode-3.2 additions */
case HB_SCRIPT_TAGALOG:
case HB_SCRIPT_TAGBANWA:
/* Unicode-4.0 additions */
case HB_SCRIPT_LIMBU:
case HB_SCRIPT_TAI_LE:
/* Unicode-4.1 additions */
case HB_SCRIPT_KHAROSHTHI:
case HB_SCRIPT_SYLOTI_NAGRI:
/* Unicode-5.1 additions */
case HB_SCRIPT_KAYAH_LI:
/* Unicode-5.2 additions */
case HB_SCRIPT_TAI_VIET:
#endif
/* Unicode-1.1 additions */
case HB_SCRIPT_BENGALI:
case HB_SCRIPT_DEVANAGARI:
case HB_SCRIPT_GUJARATI:
case HB_SCRIPT_GURMUKHI:
case HB_SCRIPT_KANNADA:
case HB_SCRIPT_MALAYALAM:
case HB_SCRIPT_ORIYA:
case HB_SCRIPT_TAMIL:
case HB_SCRIPT_TELUGU:
/* Unicode-3.0 additions */
case HB_SCRIPT_SINHALA:
/* Unicode-4.1 additions */
case HB_SCRIPT_BUGINESE:
/* Unicode-5.0 additions */
case HB_SCRIPT_BALINESE:
/* Unicode-5.1 additions */
case HB_SCRIPT_LEPCHA:
case HB_SCRIPT_REJANG:
case HB_SCRIPT_SUNDANESE:
/* Unicode-5.2 additions */
case HB_SCRIPT_JAVANESE:
case HB_SCRIPT_KAITHI:
case HB_SCRIPT_MEETEI_MAYEK:
/* Unicode-6.0 additions */
/* Unicode-6.1 additions */
case HB_SCRIPT_CHAKMA:
case HB_SCRIPT_SHARADA:
case HB_SCRIPT_TAKRI:
/* If the designer designed the font for the 'DFLT' script,
* use the default shaper. Otherwise, use the Indic shaper.
* Note that for some simple scripts, there may not be *any*
* GSUB/GPOS needed, so there may be no scripts found! */
if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T'))
return &_hb_ot_complex_shaper_default;
else
return &_hb_ot_complex_shaper_indic;
case HB_SCRIPT_KHMER:
/* A number of Khmer fonts in the wild don't have a 'pref' feature,
* and as such won't shape properly via the Indic shaper;
* however, they typically have 'liga' / 'clig' features that implement
* the necessary "reordering" by means of ligature substitutions.
* So we send such pref-less fonts through the generic shaper instead. */
if (planner->map.found_script[0] &&
hb_ot_layout_language_find_feature (planner->face, HB_OT_TAG_GSUB,
planner->map.script_index[0],
planner->map.language_index[0],
HB_TAG ('p','r','e','f'),
NULL))
return &_hb_ot_complex_shaper_indic;
else
return &_hb_ot_complex_shaper_default;
case HB_SCRIPT_MYANMAR:
/* For Myanmar, we only want to use the Myanmar shaper if the "new" script
* tag is found. For "old" script tag we want to use the default shaper. */
if (planner->map.chosen_script[0] == HB_TAG ('m','y','m','2'))
return &_hb_ot_complex_shaper_myanmar;
else
return &_hb_ot_complex_shaper_default;
/* Unicode-4.1 additions */
case HB_SCRIPT_NEW_TAI_LUE:
/* Unicode-5.1 additions */
case HB_SCRIPT_CHAM:
/* Unicode-5.2 additions */
case HB_SCRIPT_TAI_THAM:
/* If the designer designed the font for the 'DFLT' script,
* use the default shaper. Otherwise, use the Indic shaper.
* Note that for some simple scripts, there may not be *any*
* GSUB/GPOS needed, so there may be no scripts found! */
if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T'))
return &_hb_ot_complex_shaper_default;
else
return &_hb_ot_complex_shaper_sea;
}
}
#endif /* HB_OT_SHAPE_COMPLEX_PRIVATE_HH */