michael@0: /*
michael@0:  * Copyright © 2007,2008,2009  Red Hat, Inc.
michael@0:  * Copyright © 2012,2013  Google, Inc.
michael@0:  *
michael@0:  *  This is part of HarfBuzz, a text shaping library.
michael@0:  *
michael@0:  * Permission is hereby granted, without written agreement and without
michael@0:  * license or royalty fees, to use, copy, modify, and distribute this
michael@0:  * software and its documentation for any purpose, provided that the
michael@0:  * above copyright notice and the following two paragraphs appear in
michael@0:  * all copies of this software.
michael@0:  *
michael@0:  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
michael@0:  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
michael@0:  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
michael@0:  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
michael@0:  * DAMAGE.
michael@0:  *
michael@0:  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
michael@0:  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
michael@0:  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
michael@0:  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
michael@0:  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
michael@0:  *
michael@0:  * Red Hat Author(s): Behdad Esfahbod
michael@0:  * Google Author(s): Behdad Esfahbod
michael@0:  */
michael@0: 
michael@0: #ifndef HB_OT_LAYOUT_PRIVATE_HH
michael@0: #define HB_OT_LAYOUT_PRIVATE_HH
michael@0: 
michael@0: #include "hb-private.hh"
michael@0: 
michael@0: #include "hb-font-private.hh"
michael@0: #include "hb-buffer-private.hh"
michael@0: #include "hb-set-private.hh"
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * GDEF
michael@0:  */
michael@0: 
michael@0: typedef enum
michael@0: {
michael@0:   /* The following three match LookupFlags::Ignore* numbers. */
michael@0:   HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH	= 0x02u,
michael@0:   HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE	= 0x04u,
michael@0:   HB_OT_LAYOUT_GLYPH_PROPS_MARK		= 0x08u,
michael@0: 
michael@0:   /* The following are used internally; not derived from GDEF. */
michael@0:   HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED	= 0x10u,
michael@0:   HB_OT_LAYOUT_GLYPH_PROPS_LIGATED	= 0x20u,
michael@0: 
michael@0:   HB_OT_LAYOUT_GLYPH_PROPS_PRESERVE     = HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED |
michael@0: 					  HB_OT_LAYOUT_GLYPH_PROPS_LIGATED
michael@0: } hb_ot_layout_glyph_class_mask_t;
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * GSUB/GPOS
michael@0:  */
michael@0: 
michael@0: HB_INTERNAL hb_bool_t
michael@0: hb_ot_layout_lookup_would_substitute_fast (hb_face_t            *face,
michael@0: 					   unsigned int          lookup_index,
michael@0: 					   const hb_codepoint_t *glyphs,
michael@0: 					   unsigned int          glyphs_length,
michael@0: 					   hb_bool_t             zero_context);
michael@0: 
michael@0: 
michael@0: /* Should be called before all the substitute_lookup's are done. */
michael@0: HB_INTERNAL void
michael@0: hb_ot_layout_substitute_start (hb_font_t    *font,
michael@0: 			       hb_buffer_t  *buffer);
michael@0: 
michael@0: 
michael@0: struct hb_ot_layout_lookup_accelerator_t;
michael@0: 
michael@0: namespace OT {
michael@0:   struct hb_apply_context_t;
michael@0:   struct SubstLookup;
michael@0: }
michael@0: 
michael@0: HB_INTERNAL void
michael@0: hb_ot_layout_substitute_lookup (OT::hb_apply_context_t *c,
michael@0: 				const OT::SubstLookup &lookup,
michael@0: 				const hb_ot_layout_lookup_accelerator_t &accel);
michael@0: 
michael@0: 
michael@0: /* Should be called after all the substitute_lookup's are done */
michael@0: HB_INTERNAL void
michael@0: hb_ot_layout_substitute_finish (hb_font_t    *font,
michael@0: 				hb_buffer_t  *buffer);
michael@0: 
michael@0: 
michael@0: /* Should be called before all the position_lookup's are done.  Resets positions to zero. */
michael@0: HB_INTERNAL void
michael@0: hb_ot_layout_position_start (hb_font_t    *font,
michael@0: 			     hb_buffer_t  *buffer);
michael@0: 
michael@0: /* Should be called after all the position_lookup's are done */
michael@0: HB_INTERNAL void
michael@0: hb_ot_layout_position_finish (hb_font_t    *font,
michael@0: 			      hb_buffer_t  *buffer);
michael@0: 
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * hb_ot_layout_t
michael@0:  */
michael@0: 
michael@0: namespace OT {
michael@0:   struct GDEF;
michael@0:   struct GSUB;
michael@0:   struct GPOS;
michael@0: }
michael@0: 
michael@0: struct hb_ot_layout_lookup_accelerator_t
michael@0: {
michael@0:   template <typename TLookup>
michael@0:   inline void init (const TLookup &lookup)
michael@0:   {
michael@0:     digest.init ();
michael@0:     lookup.add_coverage (&digest);
michael@0:   }
michael@0: 
michael@0:   template <typename TLookup>
michael@0:   inline void fini (const TLookup &lookup)
michael@0:   {
michael@0:   }
michael@0: 
michael@0:   hb_set_digest_t digest;
michael@0: };
michael@0: 
michael@0: struct hb_ot_layout_t
michael@0: {
michael@0:   hb_blob_t *gdef_blob;
michael@0:   hb_blob_t *gsub_blob;
michael@0:   hb_blob_t *gpos_blob;
michael@0: 
michael@0:   const struct OT::GDEF *gdef;
michael@0:   const struct OT::GSUB *gsub;
michael@0:   const struct OT::GPOS *gpos;
michael@0: 
michael@0:   unsigned int gsub_lookup_count;
michael@0:   unsigned int gpos_lookup_count;
michael@0: 
michael@0:   hb_ot_layout_lookup_accelerator_t *gsub_accels;
michael@0:   hb_ot_layout_lookup_accelerator_t *gpos_accels;
michael@0: };
michael@0: 
michael@0: 
michael@0: HB_INTERNAL hb_ot_layout_t *
michael@0: _hb_ot_layout_create (hb_face_t *face);
michael@0: 
michael@0: HB_INTERNAL void
michael@0: _hb_ot_layout_destroy (hb_ot_layout_t *layout);
michael@0: 
michael@0: 
michael@0: #define hb_ot_layout_from_face(face) ((hb_ot_layout_t *) face->shaper_data.ot)
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Buffer var routines.
michael@0:  */
michael@0: 
michael@0: /* buffer var allocations, used during the entire shaping process */
michael@0: #define unicode_props0()	var2.u8[0]
michael@0: #define unicode_props1()	var2.u8[1]
michael@0: 
michael@0: /* buffer var allocations, used during the GSUB/GPOS processing */
michael@0: #define glyph_props()		var1.u16[0] /* GDEF glyph properties */
michael@0: #define lig_props()		var1.u8[2] /* GSUB/GPOS ligature tracking */
michael@0: #define syllable()		var1.u8[3] /* GSUB/GPOS shaping boundaries */
michael@0: 
michael@0: /* unicode_props */
michael@0: 
michael@0: enum {
michael@0:   MASK0_ZWJ       = 0x20u,
michael@0:   MASK0_ZWNJ      = 0x40u,
michael@0:   MASK0_IGNORABLE = 0x80u,
michael@0:   MASK0_GEN_CAT   = 0x1Fu
michael@0: };
michael@0: 
michael@0: inline void
michael@0: _hb_glyph_info_set_unicode_props (hb_glyph_info_t *info, hb_unicode_funcs_t *unicode)
michael@0: {
michael@0:   /* XXX This shouldn't be inlined, or at least not while is_default_ignorable() is inline. */
michael@0:   info->unicode_props0() = ((unsigned int) unicode->general_category (info->codepoint)) |
michael@0: 			   (unicode->is_default_ignorable (info->codepoint) ? MASK0_IGNORABLE : 0) |
michael@0: 			   (info->codepoint == 0x200C ? MASK0_ZWNJ : 0) |
michael@0: 			   (info->codepoint == 0x200D ? MASK0_ZWJ : 0);
michael@0:   info->unicode_props1() = unicode->modified_combining_class (info->codepoint);
michael@0: }
michael@0: 
michael@0: inline void
michael@0: _hb_glyph_info_set_general_category (hb_glyph_info_t *info,
michael@0: 				     hb_unicode_general_category_t gen_cat)
michael@0: {
michael@0:   info->unicode_props0() = (unsigned int) gen_cat | ((info->unicode_props0()) & ~MASK0_GEN_CAT);
michael@0: }
michael@0: 
michael@0: inline hb_unicode_general_category_t
michael@0: _hb_glyph_info_get_general_category (const hb_glyph_info_t *info)
michael@0: {
michael@0:   return (hb_unicode_general_category_t) (info->unicode_props0() & MASK0_GEN_CAT);
michael@0: }
michael@0: 
michael@0: inline void
michael@0: _hb_glyph_info_set_modified_combining_class (hb_glyph_info_t *info,
michael@0: 					     unsigned int modified_class)
michael@0: {
michael@0:   info->unicode_props1() = modified_class;
michael@0: }
michael@0: 
michael@0: inline unsigned int
michael@0: _hb_glyph_info_get_modified_combining_class (const hb_glyph_info_t *info)
michael@0: {
michael@0:   return info->unicode_props1();
michael@0: }
michael@0: 
michael@0: inline hb_bool_t
michael@0: _hb_glyph_info_is_default_ignorable (const hb_glyph_info_t *info)
michael@0: {
michael@0:   return !!(info->unicode_props0() & MASK0_IGNORABLE);
michael@0: }
michael@0: 
michael@0: inline hb_bool_t
michael@0: _hb_glyph_info_is_zwnj (const hb_glyph_info_t *info)
michael@0: {
michael@0:   return !!(info->unicode_props0() & MASK0_ZWNJ);
michael@0: }
michael@0: 
michael@0: inline hb_bool_t
michael@0: _hb_glyph_info_is_zwj (const hb_glyph_info_t *info)
michael@0: {
michael@0:   return !!(info->unicode_props0() & MASK0_ZWJ);
michael@0: }
michael@0: 
michael@0: inline void
michael@0: _hb_glyph_info_flip_joiners (hb_glyph_info_t *info)
michael@0: {
michael@0:   info->unicode_props0() ^= MASK0_ZWNJ | MASK0_ZWJ;
michael@0: }
michael@0: 
michael@0: /* lig_props: aka lig_id / lig_comp
michael@0:  *
michael@0:  * When a ligature is formed:
michael@0:  *
michael@0:  *   - The ligature glyph and any marks in between all the same newly allocated
michael@0:  *     lig_id,
michael@0:  *   - The ligature glyph will get lig_num_comps set to the number of components
michael@0:  *   - The marks get lig_comp > 0, reflecting which component of the ligature
michael@0:  *     they were applied to.
michael@0:  *   - This is used in GPOS to attach marks to the right component of a ligature
michael@0:  *     in MarkLigPos,
michael@0:  *   - Note that when marks are ligated together, much of the above is skipped
michael@0:  *     and the current lig_id reused.
michael@0:  *
michael@0:  * When a multiple-substitution is done:
michael@0:  *
michael@0:  *   - All resulting glyphs will have lig_id = 0,
michael@0:  *   - The resulting glyphs will have lig_comp = 0, 1, 2, ... respectively.
michael@0:  *   - This is used in GPOS to attach marks to the first component of a
michael@0:  *     multiple substitution in MarkBasePos.
michael@0:  *
michael@0:  * The numbers are also used in GPOS to do mark-to-mark positioning only
michael@0:  * to marks that belong to the same component of the same ligature.
michael@0:  */
michael@0: 
michael@0: static inline void
michael@0: _hb_glyph_info_clear_lig_props (hb_glyph_info_t *info)
michael@0: {
michael@0:   info->lig_props() = 0;
michael@0: }
michael@0: 
michael@0: #define IS_LIG_BASE 0x10
michael@0: 
michael@0: static inline void
michael@0: _hb_glyph_info_set_lig_props_for_ligature (hb_glyph_info_t *info,
michael@0: 					   unsigned int lig_id,
michael@0: 					   unsigned int lig_num_comps)
michael@0: {
michael@0:   info->lig_props() = (lig_id << 5) | IS_LIG_BASE | (lig_num_comps & 0x0F);
michael@0: }
michael@0: 
michael@0: static inline void
michael@0: _hb_glyph_info_set_lig_props_for_mark (hb_glyph_info_t *info,
michael@0: 				       unsigned int lig_id,
michael@0: 				       unsigned int lig_comp)
michael@0: {
michael@0:   info->lig_props() = (lig_id << 5) | (lig_comp & 0x0F);
michael@0: }
michael@0: 
michael@0: static inline void
michael@0: _hb_glyph_info_set_lig_props_for_component (hb_glyph_info_t *info, unsigned int comp)
michael@0: {
michael@0:   _hb_glyph_info_set_lig_props_for_mark (info, 0, comp);
michael@0: }
michael@0: 
michael@0: static inline unsigned int
michael@0: _hb_glyph_info_get_lig_id (const hb_glyph_info_t *info)
michael@0: {
michael@0:   return info->lig_props() >> 5;
michael@0: }
michael@0: 
michael@0: static inline bool
michael@0: _hb_glyph_info_ligated_internal (const hb_glyph_info_t *info)
michael@0: {
michael@0:   return !!(info->lig_props() & IS_LIG_BASE);
michael@0: }
michael@0: 
michael@0: static inline unsigned int
michael@0: _hb_glyph_info_get_lig_comp (const hb_glyph_info_t *info)
michael@0: {
michael@0:   if (_hb_glyph_info_ligated_internal (info))
michael@0:     return 0;
michael@0:   else
michael@0:     return info->lig_props() & 0x0F;
michael@0: }
michael@0: 
michael@0: static inline unsigned int
michael@0: _hb_glyph_info_get_lig_num_comps (const hb_glyph_info_t *info)
michael@0: {
michael@0:   if ((info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE) &&
michael@0:       _hb_glyph_info_ligated_internal (info))
michael@0:     return info->lig_props() & 0x0F;
michael@0:   else
michael@0:     return 1;
michael@0: }
michael@0: 
michael@0: static inline uint8_t
michael@0: _hb_allocate_lig_id (hb_buffer_t *buffer) {
michael@0:   uint8_t lig_id = buffer->next_serial () & 0x07;
michael@0:   if (unlikely (!lig_id))
michael@0:     lig_id = _hb_allocate_lig_id (buffer); /* in case of overflow */
michael@0:   return lig_id;
michael@0: }
michael@0: 
michael@0: /* glyph_props: */
michael@0: 
michael@0: inline void
michael@0: _hb_glyph_info_set_glyph_props (hb_glyph_info_t *info, unsigned int props)
michael@0: {
michael@0:   info->glyph_props() = props;
michael@0: }
michael@0: 
michael@0: inline unsigned int
michael@0: _hb_glyph_info_get_glyph_props (const hb_glyph_info_t *info)
michael@0: {
michael@0:   return info->glyph_props();
michael@0: }
michael@0: 
michael@0: inline bool
michael@0: _hb_glyph_info_is_base_glyph (const hb_glyph_info_t *info)
michael@0: {
michael@0:   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH);
michael@0: }
michael@0: 
michael@0: inline bool
michael@0: _hb_glyph_info_is_ligature (const hb_glyph_info_t *info)
michael@0: {
michael@0:   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE);
michael@0: }
michael@0: 
michael@0: inline bool
michael@0: _hb_glyph_info_is_mark (const hb_glyph_info_t *info)
michael@0: {
michael@0:   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MARK);
michael@0: }
michael@0: 
michael@0: static inline bool
michael@0: _hb_glyph_info_substituted (const hb_glyph_info_t *info)
michael@0: {
michael@0:   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED);
michael@0: }
michael@0: 
michael@0: static inline bool
michael@0: _hb_glyph_info_ligated (const hb_glyph_info_t *info)
michael@0: {
michael@0:   return !!(info->glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_LIGATED);
michael@0: }
michael@0: 
michael@0: /* Allocation / deallocation. */
michael@0: 
michael@0: inline void
michael@0: _hb_buffer_allocate_unicode_vars (hb_buffer_t *buffer)
michael@0: {
michael@0:   HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props0);
michael@0:   HB_BUFFER_ALLOCATE_VAR (buffer, unicode_props1);
michael@0: }
michael@0: 
michael@0: inline void
michael@0: _hb_buffer_deallocate_unicode_vars (hb_buffer_t *buffer)
michael@0: {
michael@0:   HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props0);
michael@0:   HB_BUFFER_DEALLOCATE_VAR (buffer, unicode_props1);
michael@0: }
michael@0: 
michael@0: inline void
michael@0: _hb_buffer_allocate_gsubgpos_vars (hb_buffer_t *buffer)
michael@0: {
michael@0:   HB_BUFFER_ALLOCATE_VAR (buffer, glyph_props);
michael@0:   HB_BUFFER_ALLOCATE_VAR (buffer, lig_props);
michael@0:   HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
michael@0: }
michael@0: 
michael@0: inline void
michael@0: _hb_buffer_deallocate_gsubgpos_vars (hb_buffer_t *buffer)
michael@0: {
michael@0:   HB_BUFFER_DEALLOCATE_VAR (buffer, syllable);
michael@0:   HB_BUFFER_DEALLOCATE_VAR (buffer, lig_props);
michael@0:   HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_props);
michael@0: }
michael@0: 
michael@0: /* Make sure no one directly touches our props... */
michael@0: #undef unicode_props0
michael@0: #undef unicode_props1
michael@0: #undef lig_props
michael@0: #undef glyph_props
michael@0: 
michael@0: 
michael@0: #endif /* HB_OT_LAYOUT_PRIVATE_HH */