src/hb-ot-shape-complex-myanmar.cc - third_party/harfbuzz - Git at Google

 /*
  * 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-shape-complex-myanmar.hh"
 #include "hb-ot-shape-complex-myanmar-machine.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 void
 setup_syllables_myanmar (const hb_ot_shape_plan_t *plan,
 			 hb_font_t *font,
 			 hb_buffer_t *buffer);
 static void
 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'));
   /* 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'));


   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);
     map->add_gsub_pause (nullptr);
   }

   map->add_gsub_pause (_hb_clear_syllables);

   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);

   /* We cannot setup masks here.  We save information about characters
    * and setup masks later on in a pause-callback. */

   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 void
 setup_syllables_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
 			 hb_font_t *font HB_UNUSED,
 			 hb_buffer_t *buffer)
 {
   find_syllables_myanmar (buffer);
   foreach_syllable (buffer, start, end)
     buffer->unsafe_to_break (start, end);
 }

 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 a < b ? -1 : a == b ? 0 : +1;
 }


 /* 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() == OT_Ra &&
 	info[start+1].myanmar_category() == OT_As &&
 	info[start+2].myanmar_category() == OT_H)
     {
       limit += 3;
       base = start;
       has_reph = true;
     }

     {
       if (!has_reph)
 	base = limit;

       for (unsigned int i = limit; i < end; i++)
 	if (is_consonant (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() == OT_MR) /* Pre-base reordering */
       {
 	info[i].myanmar_position() = POS_PRE_C;
 	continue;
       }
       if (info[i].myanmar_position() < POS_BASE_C) /* Left matra */
       {
 	continue;
       }
       if (info[i].myanmar_category() == OT_VS)
       {
 	info[i].myanmar_position() = info[i - 1].myanmar_position();
 	continue;
       }

       if (pos == POS_AFTER_MAIN && info[i].myanmar_category() == OT_VBlw)
       {
 	pos = POS_BELOW_C;
 	info[i].myanmar_position() = pos;
 	continue;
       }

       if (pos == POS_BELOW_C && info[i].myanmar_category() == OT_A)
       {
 	info[i].myanmar_position() = POS_BEFORE_SUB;
 	continue;
       }
       if (pos == POS_BELOW_C && info[i].myanmar_category() == OT_VBlw)
       {
 	info[i].myanmar_position() = pos;
 	continue;
       }
       if (pos == POS_BELOW_C && info[i].myanmar_category() != OT_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);
 }

 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_punctuation_cluster:
     case myanmar_non_myanmar_cluster:
       break;
   }
 }

 static void
 reorder_myanmar (const hb_ot_shape_plan_t *plan,
 		 hb_font_t *font,
 		 hb_buffer_t *buffer)
 {
   if (buffer->message (font, "start reordering myanmar"))
   {
     hb_syllabic_insert_dotted_circles (font, buffer,
 				       myanmar_broken_cluster,
 				       OT_GB);

     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);
 }


 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_myanmar =
 {
   collect_features_myanmar,
   nullptr, /* override_features */
   nullptr, /* data_create */
   nullptr, /* data_destroy */
   nullptr, /* preprocess_text */
   nullptr, /* postprocess_glyphs */
   HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
   nullptr, /* decompose */
   nullptr, /* compose */
   setup_masks_myanmar,
   HB_TAG_NONE, /* gpos_tag */
   nullptr, /* reorder_marks */
   HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
   false, /* fallback_position */
 };


 /* Ugly Zawgyi encoding.
  * Disable all auto processing.
  * https://github.com/harfbuzz/harfbuzz/issues/1162 */
 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_myanmar_zawgyi =
 {
   nullptr, /* collect_features */
   nullptr, /* override_features */
   nullptr, /* data_create */
   nullptr, /* data_destroy */
   nullptr, /* preprocess_text */
   nullptr, /* postprocess_glyphs */
   HB_OT_SHAPE_NORMALIZATION_MODE_NONE,
   nullptr, /* decompose */
   nullptr, /* compose */
   nullptr, /* setup_masks */
   HB_TAG_NONE, /* gpos_tag */
   nullptr, /* reorder_marks */
   HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
   false, /* fallback_position */
 };


 #endif
	/*
	* 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-shape-complex-myanmar.hh"
	#include "hb-ot-shape-complex-myanmar-machine.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 void
	setup_syllables_myanmar (const hb_ot_shape_plan_t *plan,
	hb_font_t *font,
	hb_buffer_t *buffer);
	static void
	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'));
	/* 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'));


	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);
	map->add_gsub_pause (nullptr);
	}

	map->add_gsub_pause (_hb_clear_syllables);

	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);

	/* We cannot setup masks here. We save information about characters
	* and setup masks later on in a pause-callback. */

	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 void
	setup_syllables_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
	hb_font_t *font HB_UNUSED,
	hb_buffer_t *buffer)
	{
	find_syllables_myanmar (buffer);
	foreach_syllable (buffer, start, end)
	buffer->unsafe_to_break (start, end);
	}

	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 a < b ? -1 : a == b ? 0 : +1;
	}


	/* 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() == OT_Ra &&
	info[start+1].myanmar_category() == OT_As &&
	info[start+2].myanmar_category() == OT_H)
	{
	limit += 3;
	base = start;
	has_reph = true;
	}

	{
	if (!has_reph)
	base = limit;

	for (unsigned int i = limit; i < end; i++)
	if (is_consonant (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() == OT_MR) /* Pre-base reordering */
	{
	info[i].myanmar_position() = POS_PRE_C;
	continue;
	}
	if (info[i].myanmar_position() < POS_BASE_C) /* Left matra */
	{
	continue;
	}
	if (info[i].myanmar_category() == OT_VS)
	{
	info[i].myanmar_position() = info[i - 1].myanmar_position();
	continue;
	}

	if (pos == POS_AFTER_MAIN && info[i].myanmar_category() == OT_VBlw)
	{
	pos = POS_BELOW_C;
	info[i].myanmar_position() = pos;
	continue;
	}

	if (pos == POS_BELOW_C && info[i].myanmar_category() == OT_A)
	{
	info[i].myanmar_position() = POS_BEFORE_SUB;
	continue;
	}
	if (pos == POS_BELOW_C && info[i].myanmar_category() == OT_VBlw)
	{
	info[i].myanmar_position() = pos;
	continue;
	}
	if (pos == POS_BELOW_C && info[i].myanmar_category() != OT_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);
	}

	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_punctuation_cluster:
	case myanmar_non_myanmar_cluster:
	break;
	}
	}

	static void
	reorder_myanmar (const hb_ot_shape_plan_t *plan,
	hb_font_t *font,
	hb_buffer_t *buffer)
	{
	if (buffer->message (font, "start reordering myanmar"))
	{
	hb_syllabic_insert_dotted_circles (font, buffer,
	myanmar_broken_cluster,
	OT_GB);

	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);
	}


	const hb_ot_complex_shaper_t _hb_ot_complex_shaper_myanmar =
	{
	collect_features_myanmar,
	nullptr, /* override_features */
	nullptr, /* data_create */
	nullptr, /* data_destroy */
	nullptr, /* preprocess_text */
	nullptr, /* postprocess_glyphs */
	HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
	nullptr, /* decompose */
	nullptr, /* compose */
	setup_masks_myanmar,
	HB_TAG_NONE, /* gpos_tag */
	nullptr, /* reorder_marks */
	HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
	false, /* fallback_position */
	};


	/* Ugly Zawgyi encoding.
	* Disable all auto processing.
	* https://github.com/harfbuzz/harfbuzz/issues/1162 */
	const hb_ot_complex_shaper_t _hb_ot_complex_shaper_myanmar_zawgyi =
	{
	nullptr, /* collect_features */
	nullptr, /* override_features */
	nullptr, /* data_create */
	nullptr, /* data_destroy */
	nullptr, /* preprocess_text */
	nullptr, /* postprocess_glyphs */
	HB_OT_SHAPE_NORMALIZATION_MODE_NONE,
	nullptr, /* decompose */
	nullptr, /* compose */
	nullptr, /* setup_masks */
	HB_TAG_NONE, /* gpos_tag */
	nullptr, /* reorder_marks */
	HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
	false, /* fallback_position */
	};


	#endif