walkero
/
harfbuzz
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

[Indic] Do Reph repositioning in final reordering like the spec says 

This introduced a failure, which we tracked down to a test case like this:

  U+092E,U+094B,U+094D,U+0930

The final character is a Ra that should be put in a syllable of it's
own.  And we do.  But it will interact with the Halant before it.  So
now we finally are convinced that we have to limit features to syllable
boundaries.  That's coming after lunch!
This commit is contained in:
Behdad Esfahbod 2012-05-10 13:45:52 +02:00
parent 4705a70269
commit dbb105883c
2 changed files with 64 additions and 41 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/hb-ot-shape-complex-indic-private.hh
View File

@ -74,8 +74,6 @@ enum indic_position_t {
POS_MATRAS,
POS_REPH,
POS_SMVD
};

103
src/hb-ot-shape-complex-indic.cc
View File

@ -332,10 +332,8 @@ initial_reordering_consonant_syllable (const hb_ot_map_t *map, hb_buffer_t *buff
info[base].indic_position() = POS_BASE_C;
/* Handle beginning Ra */
if (has_reph) {
info[start].indic_position() = POS_REPH;
info[start].mask = mask_array[RPHF];
}
if (has_reph)
info[start].indic_position() = POS_RA_TO_BECOME_REPH;
/* For old-style Indic script tags, move the first post-base Halant after
* last consonant. */
@ -382,6 +380,10 @@ initial_reordering_consonant_syllable (const hb_ot_map_t *map, hb_buffer_t *buff
{
hb_mask_t mask;
/* Reph */
if (has_reph)
info[start].mask = mask_array[RPHF];
/* Pre-base */
mask = mask_array[HALF] | mask_array[AKHN] | mask_array[CJCT];
for (i = start; i < base; i++)
@ -530,41 +532,64 @@ final_reordering_syllable (hb_buffer_t *buffer,
* 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.
*
* 1. If reph should be positioned after post-base consonant forms,
* proceed to 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.
*
* 3. If reph should be repositioned after the main consonant: from the
* first consonant not ligated with main, or find the first
* consonant that is not a potential pre-base reordering Ra.
*
*
* 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.
*
* 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.
*
* 6. Otherwise, reorder reph to the end of the syllable.
*
* o Reorder pre-base reordering consonants:
*/
/* If there's anything after the Ra that has the REPH pos, it ought to be halant.
* Which means that the font has failed to ligate the Reph. In which case, we
* shouldn't move. */
if (start + 1 < end &&
info[start].indic_position() == POS_RA_TO_BECOME_REPH &&
info[start + 1].indic_position() != POS_RA_TO_BECOME_REPH)
{
/* 1. If reph should be positioned after post-base consonant forms,
* proceed to 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.
*
* 3. If reph should be repositioned after the main consonant: from the
* first consonant not ligated with main, or find the first
* consonant that is not a potential pre-base reordering Ra.
*
*
* 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.
*
* 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.
*
* 6. Otherwise, reorder reph to the end of the syllable.
*/
start_of_last_cluster = start; /* Yay, one big cluster! */
/* Now let's go shopping for a position. */
unsigned int new_reph_pos = end - 1;
while (new_reph_pos > start && (FLAG (info[new_reph_pos].indic_position()) & (FLAG (POS_SMVD))))
new_reph_pos--;
/* Move */
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;
}
/* o Reorder pre-base reordering consonants:
*
* If a pre-base reordering consonant is found, reorder it according to
* the following rules: