--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/harfbuzz/src/hb-ot-shaper-myanmar.cc	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,390 @@
+/*
+ * Copyright © 2011,2012,2013  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
+ */
+
+#include "hb.hh"
+
+#ifndef HB_NO_OT_SHAPE
+
+#include "hb-ot-shaper-myanmar-machine.hh"
+#include "hb-ot-shaper-indic.hh"
+#include "hb-ot-layout.hh"
+
+
+/*
+ * Myanmar shaper.
+ */
+
+
+static const hb_tag_t
+myanmar_basic_features[] =
+{
+  /*
+   * Basic features.
+   * These features are applied in order, one at a time, after reordering,
+   * constrained to the syllable.
+   */
+  HB_TAG('r','p','h','f'),
+  HB_TAG('p','r','e','f'),
+  HB_TAG('b','l','w','f'),
+  HB_TAG('p','s','t','f'),
+};
+static const hb_tag_t
+myanmar_other_features[] =
+{
+  /*
+   * Other features.
+   * These features are applied all at once, after clearing syllables.
+   */
+  HB_TAG('p','r','e','s'),
+  HB_TAG('a','b','v','s'),
+  HB_TAG('b','l','w','s'),
+  HB_TAG('p','s','t','s'),
+};
+
+static inline void
+set_myanmar_properties (hb_glyph_info_t &info)
+{
+  hb_codepoint_t u = info.codepoint;
+  unsigned int type = hb_indic_get_categories (u);
+
+  info.myanmar_category() = (myanmar_category_t) (type & 0xFFu);
+}
+
+
+static inline bool
+is_one_of_myanmar (const hb_glyph_info_t &info, unsigned int flags)
+{
+  /* If it ligated, all bets are off. */
+  if (_hb_glyph_info_ligated (&info)) return false;
+  return !!(FLAG_UNSAFE (info.myanmar_category()) & flags);
+}
+
+/* Note:
+ *
+ * We treat Vowels and placeholders as if they were consonants.  This is safe because Vowels
+ * cannot happen in a consonant syllable.  The plus side however is, we can call the
+ * consonant syllable logic from the vowel syllable function and get it all right!
+ *
+ * Keep in sync with consonant_categories in the generator. */
+#define CONSONANT_FLAGS_MYANMAR (FLAG (M_Cat(C)) | FLAG (M_Cat(CS)) | FLAG (M_Cat(Ra)) | /* FLAG (M_Cat(CM)) | */ FLAG (M_Cat(IV)) | FLAG (M_Cat(GB)) | FLAG (M_Cat(DOTTEDCIRCLE)))
+
+static inline bool
+is_consonant_myanmar (const hb_glyph_info_t &info)
+{
+  return is_one_of_myanmar (info, CONSONANT_FLAGS_MYANMAR);
+}
+
+
+static bool
+setup_syllables_myanmar (const hb_ot_shape_plan_t *plan,
+			 hb_font_t *font,
+			 hb_buffer_t *buffer);
+static bool
+reorder_myanmar (const hb_ot_shape_plan_t *plan,
+		 hb_font_t *font,
+		 hb_buffer_t *buffer);
+
+static void
+collect_features_myanmar (hb_ot_shape_planner_t *plan)
+{
+  hb_ot_map_builder_t *map = &plan->map;
+
+  /* Do this before any lookups have been applied. */
+  map->add_gsub_pause (setup_syllables_myanmar);
+
+  map->enable_feature (HB_TAG('l','o','c','l'), F_PER_SYLLABLE);
+  /* The Indic specs do not require ccmp, but we apply it here since if
+   * there is a use of it, it's typically at the beginning. */
+  map->enable_feature (HB_TAG('c','c','m','p'), F_PER_SYLLABLE);
+
+
+  map->add_gsub_pause (reorder_myanmar);
+
+  for (unsigned int i = 0; i < ARRAY_LENGTH (myanmar_basic_features); i++)
+  {
+    map->enable_feature (myanmar_basic_features[i], F_MANUAL_ZWJ | F_PER_SYLLABLE);
+    map->add_gsub_pause (nullptr);
+  }
+  map->add_gsub_pause (hb_syllabic_clear_var); // Don't need syllables anymore, use stop to free buffer var
+
+  for (unsigned int i = 0; i < ARRAY_LENGTH (myanmar_other_features); i++)
+    map->enable_feature (myanmar_other_features[i], F_MANUAL_ZWJ);
+}
+
+static void
+setup_masks_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
+		     hb_buffer_t              *buffer,
+		     hb_font_t                *font HB_UNUSED)
+{
+  HB_BUFFER_ALLOCATE_VAR (buffer, myanmar_category);
+  HB_BUFFER_ALLOCATE_VAR (buffer, myanmar_position);
+
+  /* No masks, we just save information about characters. */
+
+  unsigned int count = buffer->len;
+  hb_glyph_info_t *info = buffer->info;
+  for (unsigned int i = 0; i < count; i++)
+    set_myanmar_properties (info[i]);
+}
+
+static bool
+setup_syllables_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
+			 hb_font_t *font HB_UNUSED,
+			 hb_buffer_t *buffer)
+{
+  HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
+  find_syllables_myanmar (buffer);
+  foreach_syllable (buffer, start, end)
+    buffer->unsafe_to_break (start, end);
+  return false;
+}
+
+static int
+compare_myanmar_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb)
+{
+  int a = pa->myanmar_position();
+  int b = pb->myanmar_position();
+
+  return (int) a - (int) b;
+}
+
+
+/* Rules from:
+ * https://docs.microsoft.com/en-us/typography/script-development/myanmar */
+
+static void
+initial_reordering_consonant_syllable (hb_buffer_t *buffer,
+				       unsigned int start, unsigned int end)
+{
+  hb_glyph_info_t *info = buffer->info;
+
+  unsigned int base = end;
+  bool has_reph = false;
+
+  {
+    unsigned int limit = start;
+    if (start + 3 <= end &&
+	info[start  ].myanmar_category() == M_Cat(Ra) &&
+	info[start+1].myanmar_category() == M_Cat(As) &&
+	info[start+2].myanmar_category() == M_Cat(H))
+    {
+      limit += 3;
+      base = start;
+      has_reph = true;
+    }
+
+    {
+      if (!has_reph)
+	base = limit;
+
+      for (unsigned int i = limit; i < end; i++)
+	if (is_consonant_myanmar (info[i]))
+	{
+	  base = i;
+	  break;
+	}
+    }
+  }
+
+  /* Reorder! */
+  {
+    unsigned int i = start;
+    for (; i < start + (has_reph ? 3 : 0); i++)
+      info[i].myanmar_position() = POS_AFTER_MAIN;
+    for (; i < base; i++)
+      info[i].myanmar_position() = POS_PRE_C;
+    if (i < end)
+    {
+      info[i].myanmar_position() = POS_BASE_C;
+      i++;
+    }
+    myanmar_position_t pos = POS_AFTER_MAIN;
+    /* The following loop may be ugly, but it implements all of
+     * Myanmar reordering! */
+    for (; i < end; i++)
+    {
+      if (info[i].myanmar_category() == M_Cat(MR)) /* Pre-base reordering */
+      {
+	info[i].myanmar_position() = POS_PRE_C;
+	continue;
+      }
+      if (info[i].myanmar_category() == M_Cat(VPre)) /* Left matra */
+      {
+	info[i].myanmar_position() = POS_PRE_M;
+	continue;
+      }
+      if (info[i].myanmar_category() == M_Cat(VS))
+      {
+	info[i].myanmar_position() = info[i - 1].myanmar_position();
+	continue;
+      }
+
+      if (pos == POS_AFTER_MAIN && info[i].myanmar_category() == M_Cat(VBlw))
+      {
+	pos = POS_BELOW_C;
+	info[i].myanmar_position() = pos;
+	continue;
+      }
+
+      if (pos == POS_BELOW_C && info[i].myanmar_category() == M_Cat(A))
+      {
+	info[i].myanmar_position() = POS_BEFORE_SUB;
+	continue;
+      }
+      if (pos == POS_BELOW_C && info[i].myanmar_category() == M_Cat(VBlw))
+      {
+	info[i].myanmar_position() = pos;
+	continue;
+      }
+      if (pos == POS_BELOW_C && info[i].myanmar_category() != M_Cat(A))
+      {
+	pos = POS_AFTER_SUB;
+	info[i].myanmar_position() = pos;
+	continue;
+      }
+      info[i].myanmar_position() = pos;
+    }
+  }
+
+  /* Sit tight, rock 'n roll! */
+  buffer->sort (start, end, compare_myanmar_order);
+
+  /* Flip left-matra sequence. */
+  unsigned first_left_matra = end;
+  unsigned last_left_matra = end;
+  for (unsigned int i = start; i < end; i++)
+  {
+    if (info[i].myanmar_position() == POS_PRE_M)
+    {
+      if (first_left_matra == end)
+	first_left_matra = i;
+      last_left_matra = i;
+    }
+  }
+  /* https://github.com/harfbuzz/harfbuzz/issues/3863 */
+  if (first_left_matra < last_left_matra)
+  {
+    /* No need to merge clusters, done already? */
+    buffer->reverse_range (first_left_matra, last_left_matra + 1);
+    /* Reverse back VS, etc. */
+    unsigned i = first_left_matra;
+    for (unsigned j = i; j <= last_left_matra; j++)
+      if (info[j].myanmar_category() == M_Cat(VPre))
+      {
+	buffer->reverse_range (i, j + 1);
+	i = j + 1;
+      }
+  }
+}
+
+static void
+reorder_syllable_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
+			  hb_face_t *face HB_UNUSED,
+			  hb_buffer_t *buffer,
+			  unsigned int start, unsigned int end)
+{
+  myanmar_syllable_type_t syllable_type = (myanmar_syllable_type_t) (buffer->info[start].syllable() & 0x0F);
+  switch (syllable_type) {
+
+    case myanmar_broken_cluster: /* We already inserted dotted-circles, so just call the consonant_syllable. */
+    case myanmar_consonant_syllable:
+      initial_reordering_consonant_syllable  (buffer, start, end);
+      break;
+
+    case myanmar_non_myanmar_cluster:
+      break;
+  }
+}
+
+static bool
+reorder_myanmar (const hb_ot_shape_plan_t *plan,
+		 hb_font_t *font,
+		 hb_buffer_t *buffer)
+{
+  bool ret = false;
+  if (buffer->message (font, "start reordering myanmar"))
+  {
+    if (hb_syllabic_insert_dotted_circles (font, buffer,
+					   myanmar_broken_cluster,
+					   M_Cat(DOTTEDCIRCLE)))
+      ret = true;
+
+    foreach_syllable (buffer, start, end)
+      reorder_syllable_myanmar (plan, font->face, buffer, start, end);
+    (void) buffer->message (font, "end reordering myanmar");
+  }
+
+  HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_category);
+  HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_position);
+
+  return ret;
+}
+
+
+const hb_ot_shaper_t _hb_ot_shaper_myanmar =
+{
+  collect_features_myanmar,
+  nullptr, /* override_features */
+  nullptr, /* data_create */
+  nullptr, /* data_destroy */
+  nullptr, /* preprocess_text */
+  nullptr, /* postprocess_glyphs */
+  nullptr, /* decompose */
+  nullptr, /* compose */
+  setup_masks_myanmar,
+  nullptr, /* reorder_marks */
+  HB_TAG_NONE, /* gpos_tag */
+  HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
+  HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
+  false, /* fallback_position */
+};
+
+
+#ifndef HB_NO_OT_SHAPER_MYANMAR_ZAWGYI
+/* Ugly Zawgyi encoding.
+ * Disable all auto processing.
+ * https://github.com/harfbuzz/harfbuzz/issues/1162 */
+const hb_ot_shaper_t _hb_ot_shaper_myanmar_zawgyi =
+{
+  nullptr, /* collect_features */
+  nullptr, /* override_features */
+  nullptr, /* data_create */
+  nullptr, /* data_destroy */
+  nullptr, /* preprocess_text */
+  nullptr, /* postprocess_glyphs */
+  nullptr, /* decompose */
+  nullptr, /* compose */
+  nullptr, /* setup_masks */
+  nullptr, /* reorder_marks */
+  HB_TAG_NONE, /* gpos_tag */
+  HB_OT_SHAPE_NORMALIZATION_MODE_NONE,
+  HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
+  false, /* fallback_position */
+};
+#endif
+
+
+#endif