src/hb-ot-layout-private.hh - third_party/harfbuzz - Git at Google

 /*
  * Copyright © 2007,2008,2009  Red Hat, Inc.
  * Copyright © 2012  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.
  *
  * Red Hat Author(s): Behdad Esfahbod
  * Google Author(s): Behdad Esfahbod
  */

 #ifndef HB_OT_LAYOUT_PRIVATE_HH
 #define HB_OT_LAYOUT_PRIVATE_HH

 #include "hb-private.hh"

 #include "hb-ot-layout.h"

 #include "hb-font-private.hh"
 #include "hb-buffer-private.hh"
 #include "hb-set-private.hh"


 /* buffer var allocations, used during the GSUB/GPOS processing */
 #define glyph_props()		var1.u16[0] /* GDEF glyph properties */
 #define syllable()		var1.u8[2] /* GSUB/GPOS shaping boundaries */
 #define lig_props()		var1.u8[3] /* GSUB/GPOS ligature tracking */

 /* buffer var allocations, used during the entire shaping process */
 #define unicode_props0()	var2.u8[0]
 #define unicode_props1()	var2.u8[1]


 inline void
 _hb_glyph_info_set_unicode_props (hb_glyph_info_t *info, hb_unicode_funcs_t *unicode)
 {
   info->unicode_props0() = ((unsigned int) unicode->general_category (info->codepoint)) |
 			   (unicode->is_default_ignorable (info->codepoint) ? 0x80 : 0) |
 			   (info->codepoint == 0x200C ? 0x40 : 0) |
 			   (info->codepoint == 0x200D ? 0x20 : 0);
   info->unicode_props1() = unicode->modified_combining_class (info->codepoint);
 }

 inline hb_unicode_general_category_t
 _hb_glyph_info_get_general_category (const hb_glyph_info_t *info)
 {
   return (hb_unicode_general_category_t) (info->unicode_props0() & 0x1F);
 }

 inline void
 _hb_glyph_info_set_modified_combining_class (hb_glyph_info_t *info, unsigned int modified_class)
 {
   info->unicode_props1() = modified_class;
 }

 inline unsigned int
 _hb_glyph_info_get_modified_combining_class (const hb_glyph_info_t *info)
 {
   return info->unicode_props1();
 }

 inline hb_bool_t
 _hb_glyph_info_is_default_ignorable (const hb_glyph_info_t *info)
 {
   return !!(info->unicode_props0() & 0x80);
 }

 inline hb_bool_t
 _hb_glyph_info_is_zwnj (const hb_glyph_info_t *info)
 {
   return !!(info->unicode_props0() & 0x40);
 }

 inline hb_bool_t
 _hb_glyph_info_is_zwj (const hb_glyph_info_t *info)
 {
   return !!(info->unicode_props0() & 0x20);
 }


 #define hb_ot_layout_from_face(face) ((hb_ot_layout_t *) face->shaper_data.ot)

 /*
  * GDEF
  */

 typedef enum {
   HB_OT_LAYOUT_GLYPH_PROPS_UNCLASSIFIED	= 1 << HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED,
   HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH	= 1 << HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH,
   HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE	= 1 << HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE,
   HB_OT_LAYOUT_GLYPH_PROPS_MARK		= 1 << HB_OT_LAYOUT_GLYPH_CLASS_MARK,
   HB_OT_LAYOUT_GLYPH_PROPS_COMPONENT	= 1 << HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT
 } hb_ot_layout_glyph_class_mask_t;


 /*
  * GSUB/GPOS
  */

 /* lig_id / lig_comp
  *
  * When a ligature is formed:
  *
  *   - The ligature glyph and any marks in between all the same newly allocated
  *     lig_id,
  *   - The ligature glyph will get lig_num_comps set to the number of components
  *   - The marks get lig_comp > 0, reflecting which component of the ligature
  *     they were applied to.
  *   - This is used in GPOS to attach marks to the right component of a ligature
  *     in MarkLigPos.
  *
  * When a multiple-substitution is done:
  *
  *   - All resulting glyphs will have lig_id = 0,
  *   - The resulting glyphs will have lig_comp = 0, 1, 2, ... respectively.
  *   - This is used in GPOS to attach marks to the first component of a
  *     multiple substitution in MarkBasePos.
  *
  * The numbers are also used in GPOS to do mark-to-mark positioning only
  * to marks that belong to the same component of a ligature in MarkMarPos.
  */
 #define IS_LIG_BASE 0x10
 static inline void
 set_lig_props_for_ligature (hb_glyph_info_t &info, unsigned int lig_id, unsigned int lig_num_comps)
 {
   info.lig_props() = (lig_id << 5) | IS_LIG_BASE | (lig_num_comps & 0x0F);
 }
 static inline void
 set_lig_props_for_mark (hb_glyph_info_t &info, unsigned int lig_id, unsigned int lig_comp)
 {
   info.lig_props() = (lig_id << 5) | (lig_comp & 0x0F);
 }
 static inline void
 set_lig_props_for_component (hb_glyph_info_t &info, unsigned int comp)
 {
   set_lig_props_for_mark (info, 0, comp);
 }

 static inline unsigned int
 get_lig_id (const hb_glyph_info_t &info)
 {
   return info.lig_props() >> 5;
 }
 static inline bool
 is_a_ligature (const hb_glyph_info_t &info)
 {
   return !!(info.lig_props() & IS_LIG_BASE);
 }
 static inline unsigned int
 get_lig_comp (const hb_glyph_info_t &info)
 {
   if (is_a_ligature (info))
     return 0;
   else
     return info.lig_props() & 0x0F;
 }
 static inline unsigned int
 get_lig_num_comps (const hb_glyph_info_t &info)
 {
   if ((info.glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE) && is_a_ligature (info))
     return info.lig_props() & 0x0F;
   else
     return 1;
 }

 static inline uint8_t allocate_lig_id (hb_buffer_t *buffer) {
   uint8_t lig_id = buffer->next_serial () & 0x07;
   if (unlikely (!lig_id))
     lig_id = allocate_lig_id (buffer); /* in case of overflow */
   return lig_id;
 }


 /*
  * GSUBGPOS
  */

 /* Always returns true for GPOS, but make writing code easier. */
 HB_INTERNAL bool
 hb_ot_layout_lookup_is_inplace (hb_face_t    *face,
 				hb_tag_t      table_tag,
 				unsigned int  lookup_index);


 /*
  * GSUB
  */

 HB_INTERNAL hb_bool_t
 hb_ot_layout_lookup_would_substitute_fast (hb_face_t            *face,
 					   unsigned int          lookup_index,
 					   const hb_codepoint_t *glyphs,
 					   unsigned int          glyphs_length,
 					   hb_bool_t             zero_context);


 /* Should be called before all the substitute_lookup's are done. */
 HB_INTERNAL void
 hb_ot_layout_substitute_start (hb_font_t    *font,
 			       hb_buffer_t  *buffer);

 HB_INTERNAL hb_bool_t
 hb_ot_layout_substitute_lookup (hb_font_t    *font,
 				hb_buffer_t  *buffer,
 				unsigned int  lookup_index,
 				unsigned int  start,
 				unsigned int  end,
 				hb_mask_t     mask,
 				hb_bool_t     auto_zwj);

 /* Should be called after all the substitute_lookup's are done */
 HB_INTERNAL void
 hb_ot_layout_substitute_finish (hb_font_t    *font,
 				hb_buffer_t  *buffer);


 /*
  * GPOS
  */

 /* Should be called before all the position_lookup's are done.  Resets positions to zero. */
 HB_INTERNAL void
 hb_ot_layout_position_start (hb_font_t    *font,
 			     hb_buffer_t  *buffer);

 HB_INTERNAL hb_bool_t
 hb_ot_layout_position_lookup (hb_font_t    *font,
 			      hb_buffer_t  *buffer,
 			      unsigned int  lookup_index,
 			      unsigned int  start,
 			      unsigned int  end,
 			      hb_mask_t     mask,
 			      hb_bool_t     auto_zwj);

 /* Should be called after all the position_lookup's are done */
 HB_INTERNAL void
 hb_ot_layout_position_finish (hb_font_t    *font,
 			      hb_buffer_t  *buffer);


 /*
  * hb_ot_layout_t
  */

 namespace OT {
   struct GDEF;
   struct GSUB;
   struct GPOS;
 }

 struct hb_ot_layout_t
 {
   hb_blob_t *gdef_blob;
   hb_blob_t *gsub_blob;
   hb_blob_t *gpos_blob;

   const struct OT::GDEF *gdef;
   const struct OT::GSUB *gsub;
   const struct OT::GPOS *gpos;

   unsigned int gsub_lookup_count;
   unsigned int gpos_lookup_count;

   hb_set_digest_t *gsub_digests;
   hb_set_digest_t *gpos_digests;
 };


 HB_INTERNAL hb_ot_layout_t *
 _hb_ot_layout_create (hb_face_t *face);

 HB_INTERNAL void
 _hb_ot_layout_destroy (hb_ot_layout_t *layout);


 #endif /* HB_OT_LAYOUT_PRIVATE_HH */
	/*
	* Copyright © 2007,2008,2009 Red Hat, Inc.
	* Copyright © 2012 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.
	*
	* Red Hat Author(s): Behdad Esfahbod
	* Google Author(s): Behdad Esfahbod
	*/

	#ifndef HB_OT_LAYOUT_PRIVATE_HH
	#define HB_OT_LAYOUT_PRIVATE_HH

	#include "hb-private.hh"

	#include "hb-ot-layout.h"

	#include "hb-font-private.hh"
	#include "hb-buffer-private.hh"
	#include "hb-set-private.hh"


	/* buffer var allocations, used during the GSUB/GPOS processing */
	#define glyph_props() var1.u16[0] /* GDEF glyph properties */
	#define syllable() var1.u8[2] /* GSUB/GPOS shaping boundaries */
	#define lig_props() var1.u8[3] /* GSUB/GPOS ligature tracking */

	/* buffer var allocations, used during the entire shaping process */
	#define unicode_props0() var2.u8[0]
	#define unicode_props1() var2.u8[1]


	inline void
	_hb_glyph_info_set_unicode_props (hb_glyph_info_t info, hb_unicode_funcs_t unicode)
	{
	info->unicode_props0() = ((unsigned int) unicode->general_category (info->codepoint)) \|
	(unicode->is_default_ignorable (info->codepoint) ? 0x80 : 0) \|
	(info->codepoint == 0x200C ? 0x40 : 0) \|
	(info->codepoint == 0x200D ? 0x20 : 0);
	info->unicode_props1() = unicode->modified_combining_class (info->codepoint);
	}

	inline hb_unicode_general_category_t
	_hb_glyph_info_get_general_category (const hb_glyph_info_t *info)
	{
	return (hb_unicode_general_category_t) (info->unicode_props0() & 0x1F);
	}

	inline void
	_hb_glyph_info_set_modified_combining_class (hb_glyph_info_t *info, unsigned int modified_class)
	{
	info->unicode_props1() = modified_class;
	}

	inline unsigned int
	_hb_glyph_info_get_modified_combining_class (const hb_glyph_info_t *info)
	{
	return info->unicode_props1();
	}

	inline hb_bool_t
	_hb_glyph_info_is_default_ignorable (const hb_glyph_info_t *info)
	{
	return !!(info->unicode_props0() & 0x80);
	}

	inline hb_bool_t
	_hb_glyph_info_is_zwnj (const hb_glyph_info_t *info)
	{
	return !!(info->unicode_props0() & 0x40);
	}

	inline hb_bool_t
	_hb_glyph_info_is_zwj (const hb_glyph_info_t *info)
	{
	return !!(info->unicode_props0() & 0x20);
	}


	#define hb_ot_layout_from_face(face) ((hb_ot_layout_t *) face->shaper_data.ot)

	/*
	* GDEF
	*/

	typedef enum {
	HB_OT_LAYOUT_GLYPH_PROPS_UNCLASSIFIED = 1 << HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED,
	HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH = 1 << HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH,
	HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE = 1 << HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE,
	HB_OT_LAYOUT_GLYPH_PROPS_MARK = 1 << HB_OT_LAYOUT_GLYPH_CLASS_MARK,
	HB_OT_LAYOUT_GLYPH_PROPS_COMPONENT = 1 << HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT
	} hb_ot_layout_glyph_class_mask_t;



	/*
	* GSUB/GPOS
	*/

	/* lig_id / lig_comp
	*
	* When a ligature is formed:
	*
	* - The ligature glyph and any marks in between all the same newly allocated
	* lig_id,
	* - The ligature glyph will get lig_num_comps set to the number of components
	* - The marks get lig_comp > 0, reflecting which component of the ligature
	* they were applied to.
	* - This is used in GPOS to attach marks to the right component of a ligature
	* in MarkLigPos.
	*
	* When a multiple-substitution is done:
	*
	* - All resulting glyphs will have lig_id = 0,
	* - The resulting glyphs will have lig_comp = 0, 1, 2, ... respectively.
	* - This is used in GPOS to attach marks to the first component of a
	* multiple substitution in MarkBasePos.
	*
	* The numbers are also used in GPOS to do mark-to-mark positioning only
	* to marks that belong to the same component of a ligature in MarkMarPos.
	*/
	#define IS_LIG_BASE 0x10
	static inline void
	set_lig_props_for_ligature (hb_glyph_info_t &info, unsigned int lig_id, unsigned int lig_num_comps)
	{
	info.lig_props() = (lig_id << 5) \| IS_LIG_BASE \| (lig_num_comps & 0x0F);
	}
	static inline void
	set_lig_props_for_mark (hb_glyph_info_t &info, unsigned int lig_id, unsigned int lig_comp)
	{
	info.lig_props() = (lig_id << 5) \| (lig_comp & 0x0F);
	}
	static inline void
	set_lig_props_for_component (hb_glyph_info_t &info, unsigned int comp)
	{
	set_lig_props_for_mark (info, 0, comp);
	}

	static inline unsigned int
	get_lig_id (const hb_glyph_info_t &info)
	{
	return info.lig_props() >> 5;
	}
	static inline bool
	is_a_ligature (const hb_glyph_info_t &info)
	{
	return !!(info.lig_props() & IS_LIG_BASE);
	}
	static inline unsigned int
	get_lig_comp (const hb_glyph_info_t &info)
	{
	if (is_a_ligature (info))
	return 0;
	else
	return info.lig_props() & 0x0F;
	}
	static inline unsigned int
	get_lig_num_comps (const hb_glyph_info_t &info)
	{
	if ((info.glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE) && is_a_ligature (info))
	return info.lig_props() & 0x0F;
	else
	return 1;
	}

	static inline uint8_t allocate_lig_id (hb_buffer_t *buffer) {
	uint8_t lig_id = buffer->next_serial () & 0x07;
	if (unlikely (!lig_id))
	lig_id = allocate_lig_id (buffer); /* in case of overflow */
	return lig_id;
	}



	/*
	* GSUBGPOS
	*/

	/* Always returns true for GPOS, but make writing code easier. */
	HB_INTERNAL bool
	hb_ot_layout_lookup_is_inplace (hb_face_t *face,
	hb_tag_t table_tag,
	unsigned int lookup_index);



	/*
	* GSUB
	*/

	HB_INTERNAL hb_bool_t
	hb_ot_layout_lookup_would_substitute_fast (hb_face_t *face,
	unsigned int lookup_index,
	const hb_codepoint_t *glyphs,
	unsigned int glyphs_length,
	hb_bool_t zero_context);


	/* Should be called before all the substitute_lookup's are done. */
	HB_INTERNAL void
	hb_ot_layout_substitute_start (hb_font_t *font,
	hb_buffer_t *buffer);

	HB_INTERNAL hb_bool_t
	hb_ot_layout_substitute_lookup (hb_font_t *font,
	hb_buffer_t *buffer,
	unsigned int lookup_index,
	unsigned int start,
	unsigned int end,
	hb_mask_t mask,
	hb_bool_t auto_zwj);

	/* Should be called after all the substitute_lookup's are done */
	HB_INTERNAL void
	hb_ot_layout_substitute_finish (hb_font_t *font,
	hb_buffer_t *buffer);



	/*
	* GPOS
	*/

	/* Should be called before all the position_lookup's are done. Resets positions to zero. */
	HB_INTERNAL void
	hb_ot_layout_position_start (hb_font_t *font,
	hb_buffer_t *buffer);

	HB_INTERNAL hb_bool_t
	hb_ot_layout_position_lookup (hb_font_t *font,
	hb_buffer_t *buffer,
	unsigned int lookup_index,
	unsigned int start,
	unsigned int end,
	hb_mask_t mask,
	hb_bool_t auto_zwj);

	/* Should be called after all the position_lookup's are done */
	HB_INTERNAL void
	hb_ot_layout_position_finish (hb_font_t *font,
	hb_buffer_t *buffer);



	/*
	* hb_ot_layout_t
	*/

	namespace OT {
	struct GDEF;
	struct GSUB;
	struct GPOS;
	}

	struct hb_ot_layout_t
	{
	hb_blob_t *gdef_blob;
	hb_blob_t *gsub_blob;
	hb_blob_t *gpos_blob;

	const struct OT::GDEF *gdef;
	const struct OT::GSUB *gsub;
	const struct OT::GPOS *gpos;

	unsigned int gsub_lookup_count;
	unsigned int gpos_lookup_count;

	hb_set_digest_t *gsub_digests;
	hb_set_digest_t *gpos_digests;
	};


	HB_INTERNAL hb_ot_layout_t *
	_hb_ot_layout_create (hb_face_t *face);

	HB_INTERNAL void
	_hb_ot_layout_destroy (hb_ot_layout_t *layout);



	#endif /* HB_OT_LAYOUT_PRIVATE_HH */