@ -68,31 +68,30 @@ static unsigned int get_joining_type (hb_codepoint_t u, hb_unicode_general_categ
) ? JOINING_TYPE_T : JOINING_TYPE_U ;
}
# define FEATURE_IS_SYRIAC(tag) hb_in_range<unsigned char> ((unsigned char) (tag), '2', '3')
static const hb_tag_t arabic_features [ ] =
{
HB_TAG ( ' i ' , ' n ' , ' i ' , ' t ' ) ,
HB_TAG ( ' m ' , ' e ' , ' d ' , ' i ' ) ,
HB_TAG ( ' f ' , ' i ' , ' n ' , ' a ' ) ,
HB_TAG ( ' i ' , ' s ' , ' o ' , ' l ' ) ,
/* Syriac */
HB_TAG ( ' m ' , ' e ' , ' d ' , ' 2 ' ) ,
HB_TAG ( ' f ' , ' i ' , ' n ' , ' a ' ) ,
HB_TAG ( ' f ' , ' i ' , ' n ' , ' 2 ' ) ,
HB_TAG ( ' f ' , ' i ' , ' n ' , ' 3 ' ) ,
HB_TAG ( ' m ' , ' e ' , ' d ' , ' i ' ) ,
HB_TAG ( ' m ' , ' e ' , ' d ' , ' 2 ' ) ,
HB_TAG ( ' i ' , ' n ' , ' i ' , ' t ' ) ,
HB_TAG_NONE
} ;
/* Same order as the feature array */
enum {
INIT ,
MEDI ,
FINA ,
ISOL ,
/* Syriac */
MED2 ,
FINA ,
FIN2 ,
FIN3 ,
MEDI ,
MED2 ,
INIT ,
NONE ,
@ -145,14 +144,23 @@ collect_features_arabic (hb_ot_shape_planner_t *plan)
{
hb_ot_map_builder_t * map = & plan - > map ;
/* For Language forms (in ArabicOT speak), we do the iso/fina/medi/init together,
* then rlig and calt each in their own stage . This makes IranNastaliq ' s ALLAH
* ligature work correctly . It ' s unfortunate though . . .
/* We apply features according to the Arabic spec, with pauses
* in between most .
*
* This also makes Arial Bold in Windows7 work . See :
* The pause between init / medi / . . . and rlig is required . See eg :
* https : //bugzilla.mozilla.org/show_bug.cgi?id=644184
*
* TODO : Add test cases for these two .
* The pauses between init / medi / . . . themselves are not necessarily
* needed as only one of those features is applied to any character .
* The only difference it makes is when fonts have contextual
* substitutions . We now follow the order of the spec , which makes
* for better experience if that ' s what Uniscribe is doing .
*
* At least for Arabic , looks like Uniscribe has a pause between
* rlig and calt . Otherwise the IranNastaliq ' s ALLAH ligature won ' t
* work . However , testing shows that rlig and calt are applied
* together for Mongolian in Uniscribe . As such , we only add a
* pause for Arabic , not other scripts .
*/
map - > add_gsub_pause ( nuke_joiners ) ;
@ -163,12 +171,15 @@ collect_features_arabic (hb_ot_shape_planner_t *plan)
map - > add_gsub_pause ( NULL ) ;
for ( unsigned int i = 0 ; i < ARABIC_NUM_FEATURES ; i + + )
map - > add_feature ( arabic_features [ i ] , 1 , i < 4 ? F_HAS_FALLBACK : F_NONE ) ; /* The first four features have fallback. */
map - > add_gsub_pause ( NULL ) ;
{
bool has_fallback = plan - > props . script = = HB_SCRIPT_ARABIC & & ! FEATURE_IS_SYRIAC ( arabic_features [ i ] ) ;
map - > add_feature ( arabic_features [ i ] , 1 , has_fallback ? F_HAS_FALLBACK : F_NONE ) ;
map - > add_gsub_pause ( NULL ) ;
}
map - > add_feature ( HB_TAG ( ' r ' , ' l ' , ' i ' , ' g ' ) , 1 , F_GLOBAL | F_HAS_FALLBACK ) ;
map - > add_gsub_pause ( arabic_fallback_shape ) ;
if ( plan - > props . script = = HB_SCRIPT_ARABIC )
map - > add_gsub_pause ( arabic_fallback_shape ) ;
map - > add_global_bool_feature ( HB_TAG ( ' c ' , ' a ' , ' l ' , ' t ' ) ) ;
map - > add_gsub_pause ( NULL ) ;
@ -202,8 +213,9 @@ data_create_arabic (const hb_ot_shape_plan_t *plan)
arabic_plan - > do_fallback = plan - > props . script = = HB_SCRIPT_ARABIC ;
for ( unsigned int i = 0 ; i < ARABIC_NUM_FEATURES ; i + + ) {
arabic_plan - > mask_array [ i ] = plan - > map . get_1_mask ( arabic_features [ i ] ) ;
if ( i < 4 )
arabic_plan - > do_fallback = arabic_plan - > do_fallback & & plan - > map . needs_fallback ( arabic_features [ i ] ) ;
arabic_plan - > do_fallback = arabic_plan - > do_fallback & &
! FEATURE_IS_SYRIAC ( arabic_features [ i ] ) & &
plan - > map . needs_fallback ( arabic_features [ i ] ) ;
}
return arabic_plan ;
Behdad Esfahbod
10 years ago