HarfBuzz: Update to version 6.0.0

1 files changed, 16 insertions, 0 deletions

diff --git a/thirdparty/harfbuzz/src/hb-ucd.cc b/thirdparty/harfbuzz/src/hb-ucd.cc
index baea224a25..4c8b1ee5e6 100644
--- a/thirdparty/harfbuzz/src/hb-ucd.cc
+++ b/thirdparty/harfbuzz/src/hb-ucd.cc
@@ -129,12 +129,16 @@ hb_ucd_compose (hb_unicode_funcs_t *ufuncs HB_UNUSED,
 		hb_codepoint_t a, hb_codepoint_t b, hb_codepoint_t *ab,
 		void *user_data HB_UNUSED)
 {
+  // Hangul is handled algorithmically.
   if (_hb_ucd_compose_hangul (a, b, ab)) return true;
 
   hb_codepoint_t u = 0;
 
   if ((a & 0xFFFFF800u) == 0x0000u && (b & 0xFFFFFF80) == 0x0300u)
   {
+    /* If "a" is small enough and "b" is in the U+0300 range,
+     * the composition data is encoded in a 32bit array sorted
+     * by "a,b" pair. */
     uint32_t k = HB_CODEPOINT_ENCODE3_11_7_14 (a, b, 0);
     const uint32_t *v = hb_bsearch (k,
 				    _hb_ucd_dm2_u32_map,
@@ -146,6 +150,8 @@ hb_ucd_compose (hb_unicode_funcs_t *ufuncs HB_UNUSED,
   }
   else
   {
+    /* Otherwise it is stored in a 64bit array sorted by
+     * "a,b" pair. */
     uint64_t k = HB_CODEPOINT_ENCODE3 (a, b, 0);
     const uint64_t *v = hb_bsearch (k,
 				    _hb_ucd_dm2_u64_map,
@@ -170,15 +176,22 @@ hb_ucd_decompose (hb_unicode_funcs_t *ufuncs HB_UNUSED,
 
   unsigned i = _hb_ucd_dm (ab);
 
+  /* If no data, there's no decomposition. */
   if (likely (!i)) return false;
   i--;
 
+  /* Check if it's a single-character decomposition. */
   if (i < ARRAY_LENGTH (_hb_ucd_dm1_p0_map) + ARRAY_LENGTH (_hb_ucd_dm1_p2_map))
   {
+    /* Single-character decompositions currently are only in plane 0 or plane 2. */
     if (i < ARRAY_LENGTH (_hb_ucd_dm1_p0_map))
+    {
+      /* Plane 0. */
       *a = _hb_ucd_dm1_p0_map[i];
+    }
     else
     {
+      /* Plane 2. */
       i -= ARRAY_LENGTH (_hb_ucd_dm1_p0_map);
       *a = 0x20000 | _hb_ucd_dm1_p2_map[i];
     }
@@ -187,8 +200,10 @@ hb_ucd_decompose (hb_unicode_funcs_t *ufuncs HB_UNUSED,
   }
   i -= ARRAY_LENGTH (_hb_ucd_dm1_p0_map) + ARRAY_LENGTH (_hb_ucd_dm1_p2_map);
 
+  /* Otherwise they are encoded either in a 32bit array or a 64bit array. */
   if (i < ARRAY_LENGTH (_hb_ucd_dm2_u32_map))
   {
+    /* 32bit array. */
     uint32_t v = _hb_ucd_dm2_u32_map[i];
     *a = HB_CODEPOINT_DECODE3_11_7_14_1 (v);
     *b = HB_CODEPOINT_DECODE3_11_7_14_2 (v);
@@ -196,6 +211,7 @@ hb_ucd_decompose (hb_unicode_funcs_t *ufuncs HB_UNUSED,
   }
   i -= ARRAY_LENGTH (_hb_ucd_dm2_u32_map);
 
+  /* 64bit array. */
   uint64_t v = _hb_ucd_dm2_u64_map[i];
   *a = HB_CODEPOINT_DECODE3_1 (v);
   *b = HB_CODEPOINT_DECODE3_2 (v);