[Indic] Add runtime Uniscribe bug compatibility mode!
Enable by setting envvar:
HB_OT_INDIC_OPTIONS=uniscribe-bug-compatible
Plus, LeftMatra+Halant "feature".
diff --git a/src/hb-ot-shape-complex-indic.cc b/src/hb-ot-shape-complex-indic.cc
index 0c6f021..4d0c2be 100644
--- a/src/hb-ot-shape-complex-indic.cc
+++ b/src/hb-ot-shape-complex-indic.cc
@@ -24,10 +24,19 @@
* Google Author(s): Behdad Esfahbod
*/
-#define UNISCRIBE_BUG_COMPATIBLE 1
-
#include "hb-ot-shape-complex-indic-private.hh"
+static const struct indic_options_t
+{
+ indic_options_t (void)
+ {
+ char *c = getenv ("HB_OT_INDIC_OPTIONS");
+ uniscribe_bug_compatible = c && strstr (c, "uniscribe-bug-compatible");
+ }
+
+ bool uniscribe_bug_compatible;
+} options;
+
static int
compare_codepoint (const void *pa, const void *pb)
{
@@ -357,10 +366,26 @@
}
/* Attach ZWJ, ZWNJ, nukta, and halant to previous char to move with them. */
- for (unsigned int i = start + 1; i < end; i++)
- if ((FLAG (info[i].indic_category()) &
- (FLAG (OT_ZWNJ) | FLAG (OT_ZWJ) | FLAG (OT_N) | FLAG (OT_H))))
- info[i].indic_position() = info[i - 1].indic_position();
+ if (!options.uniscribe_bug_compatible)
+ {
+ /* Please update the Uniscribe branch when touching this! */
+ for (unsigned int i = start + 1; i < end; i++)
+ if ((FLAG (info[i].indic_category()) & (FLAG (OT_ZWNJ) | FLAG (OT_ZWJ) | FLAG (OT_N) | FLAG (OT_H))))
+ info[i].indic_position() = info[i - 1].indic_position();
+ } else {
+ /* Please update the non-Uniscribe branch when touching this! */
+ for (unsigned int i = start + 1; i < end; i++)
+ if ((FLAG (info[i].indic_category()) & (FLAG (OT_ZWNJ) | FLAG (OT_ZWJ) | FLAG (OT_N) | FLAG (OT_H)))) {
+ info[i].indic_position() = info[i - 1].indic_position();
+ if (info[i].indic_category() == OT_H && info[i].indic_position() == POS_LEFT_MATRA)
+ for (unsigned int j = i; j > start; j--)
+ if (info[j - 1].indic_position() != POS_LEFT_MATRA) {
+ /* Uniscribe doesn't move the Halant with Left Matra. */
+ info[i].indic_position() = info[j - 1].indic_position();
+ break;
+ }
+ }
+ }
/* We do bubble-sort, skip malicious clusters attempts */
if (end - start < 64)
@@ -666,11 +691,8 @@
/* Finish off the clusters and go home! */
- /* For testing purposes we want to enable this to test against Uniscribe.
- * One day when we don't compare to Uniscribe output anymore, we want to
- * disable this because we believe it would make for superior cursor
- * positioning. */
- if (UNISCRIBE_BUG_COMPATIBLE) {
+ if (!options.uniscribe_bug_compatible)
+ {
/* This is what Uniscribe does. Ie. add cluster boundaries after Halant,ZWNJ.
* This means, half forms are submerged into the main consonants cluster.
* This is unnecessary, and makes cursor positioning harder, but that's what
