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/*
* Copyright © 2009,2010 Red Hat, Inc.
* Copyright © 2010,2011,2012,2013 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.
*
* Red Hat Author(s): Behdad Esfahbod
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_OT_MAP_HH
#define HB_OT_MAP_HH
#include "hb-buffer.hh"
#define HB_OT_MAP_MAX_BITS 8u
#define HB_OT_MAP_MAX_VALUE ((1u << HB_OT_MAP_MAX_BITS) - 1u)
struct hb_ot_shape_plan_t;
static const hb_tag_t table_tags[2] = {HB_OT_TAG_GSUB, HB_OT_TAG_GPOS};
struct hb_ot_map_t
{
friend struct hb_ot_map_builder_t;
public:
struct feature_map_t {
hb_tag_t tag; /* should be first for our bsearch to work */
unsigned int index[2]; /* GSUB/GPOS */
unsigned int stage[2]; /* GSUB/GPOS */
unsigned int shift;
hb_mask_t mask;
hb_mask_t _1_mask; /* mask for value=1, for quick access */
unsigned int needs_fallback : 1;
unsigned int auto_zwnj : 1;
unsigned int auto_zwj : 1;
unsigned int random : 1;
unsigned int per_syllable : 1;
int cmp (const hb_tag_t tag_) const
{ return tag_ < tag ? -1 : tag_ > tag ? 1 : 0; }
HB_INTERNAL static int cmp (const void *pa, const void *pb)
{
const feature_map_t *a = (const feature_map_t *) pa;
const feature_map_t *b = (const feature_map_t *) pb;
return a->tag < b->tag ? -1 : a->tag > b->tag ? 1 : 0;
}
};
struct lookup_map_t {
unsigned short index;
unsigned short auto_zwnj : 1;
unsigned short auto_zwj : 1;
unsigned short random : 1;
unsigned short per_syllable : 1;
hb_mask_t mask;
hb_tag_t feature_tag;
HB_INTERNAL static int cmp (const void *pa, const void *pb)
{
const lookup_map_t *a = (const lookup_map_t *) pa;
const lookup_map_t *b = (const lookup_map_t *) pb;
return a->index < b->index ? -1 : a->index > b->index ? 1 : 0;
}
};
/* Pause functions return true if new glyph indices might have been
* added to the buffer. This is used to update buffer digest. */
typedef bool (*pause_func_t) (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer);
struct stage_map_t {
unsigned int last_lookup; /* Cumulative */
pause_func_t pause_func;
};
void init ()
{
hb_memset (this, 0, sizeof (*this));
features.init0 ();
for (unsigned int table_index = 0; table_index < 2; table_index++)
{
lookups[table_index].init0 ();
stages[table_index].init0 ();
}
}
void fini ()
{
features.fini ();
for (unsigned int table_index = 0; table_index < 2; table_index++)
{
lookups[table_index].fini ();
stages[table_index].fini ();
}
}
hb_mask_t get_global_mask () const { return global_mask; }
hb_mask_t get_mask (hb_tag_t feature_tag, unsigned int *shift = nullptr) const
{
const feature_map_t *map = features.bsearch (feature_tag);
if (shift) *shift = map ? map->shift : 0;
return map ? map->mask : 0;
}
bool needs_fallback (hb_tag_t feature_tag) const
{
const feature_map_t *map = features.bsearch (feature_tag);
return map ? map->needs_fallback : false;
}
hb_mask_t get_1_mask (hb_tag_t feature_tag) const
{
const feature_map_t *map = features.bsearch (feature_tag);
return map ? map->_1_mask : 0;
}
unsigned int get_feature_index (unsigned int table_index, hb_tag_t feature_tag) const
{
const feature_map_t *map = features.bsearch (feature_tag);
return map ? map->index[table_index] : HB_OT_LAYOUT_NO_FEATURE_INDEX;
}
unsigned int get_feature_stage (unsigned int table_index, hb_tag_t feature_tag) const
{
const feature_map_t *map = features.bsearch (feature_tag);
return map ? map->stage[table_index] : UINT_MAX;
}
hb_array_t<const hb_ot_map_t::lookup_map_t>
get_stage_lookups (unsigned int table_index, unsigned int stage) const
{
if (unlikely (stage > stages[table_index].length))
return hb_array<const hb_ot_map_t::lookup_map_t> (nullptr, 0);
unsigned int start = stage ? stages[table_index][stage - 1].last_lookup : 0;
unsigned int end = stage < stages[table_index].length ? stages[table_index][stage].last_lookup : lookups[table_index].length;
return lookups[table_index].as_array ().sub_array (start, end - start);
}
HB_INTERNAL void collect_lookups (unsigned int table_index, hb_set_t *lookups) const;
template <typename Proxy>
HB_INTERNAL void apply (const Proxy &proxy,
const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
HB_INTERNAL void substitute (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
HB_INTERNAL void position (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
public:
hb_tag_t chosen_script[2];
bool found_script[2];
private:
hb_mask_t global_mask = 0;
hb_sorted_vector_t<feature_map_t> features;
hb_vector_t<lookup_map_t> lookups[2]; /* GSUB/GPOS */
hb_vector_t<stage_map_t> stages[2]; /* GSUB/GPOS */
};
enum hb_ot_map_feature_flags_t
{
F_NONE = 0x0000u,
F_GLOBAL = 0x0001u, /* Feature applies to all characters; results in no mask allocated for it. */
F_HAS_FALLBACK = 0x0002u, /* Has fallback implementation, so include mask bit even if feature not found. */
F_MANUAL_ZWNJ = 0x0004u, /* Don't skip over ZWNJ when matching **context**. */
F_MANUAL_ZWJ = 0x0008u, /* Don't skip over ZWJ when matching **input**. */
F_MANUAL_JOINERS = F_MANUAL_ZWNJ | F_MANUAL_ZWJ,
F_GLOBAL_MANUAL_JOINERS= F_GLOBAL | F_MANUAL_JOINERS,
F_GLOBAL_HAS_FALLBACK = F_GLOBAL | F_HAS_FALLBACK,
F_GLOBAL_SEARCH = 0x0010u, /* If feature not found in LangSys, look for it in global feature list and pick one. */
F_RANDOM = 0x0020u, /* Randomly select a glyph from an AlternateSubstFormat1 subtable. */
F_PER_SYLLABLE = 0x0040u /* Contain lookup application to within syllable. */
};
HB_MARK_AS_FLAG_T (hb_ot_map_feature_flags_t);
struct hb_ot_map_feature_t
{
hb_tag_t tag;
hb_ot_map_feature_flags_t flags;
};
struct hb_ot_shape_plan_key_t;
struct hb_ot_map_builder_t
{
public:
HB_INTERNAL hb_ot_map_builder_t (hb_face_t *face_,
const hb_segment_properties_t &props_);
HB_INTERNAL ~hb_ot_map_builder_t ();
HB_INTERNAL void add_feature (hb_tag_t tag,
hb_ot_map_feature_flags_t flags=F_NONE,
unsigned int value=1);
HB_INTERNAL bool has_feature (hb_tag_t tag);
void add_feature (const hb_ot_map_feature_t &feat)
{ add_feature (feat.tag, feat.flags); }
void enable_feature (hb_tag_t tag,
hb_ot_map_feature_flags_t flags=F_NONE,
unsigned int value=1)
{ add_feature (tag, F_GLOBAL | flags, value); }
void disable_feature (hb_tag_t tag)
{ add_feature (tag, F_GLOBAL, 0); }
void add_gsub_pause (hb_ot_map_t::pause_func_t pause_func)
{ add_pause (0, pause_func); }
void add_gpos_pause (hb_ot_map_t::pause_func_t pause_func)
{ add_pause (1, pause_func); }
HB_INTERNAL void compile (hb_ot_map_t &m,
const hb_ot_shape_plan_key_t &key);
private:
HB_INTERNAL void add_lookups (hb_ot_map_t &m,
unsigned int table_index,
unsigned int feature_index,
unsigned int variations_index,
hb_mask_t mask,
bool auto_zwnj = true,
bool auto_zwj = true,
bool random = false,
bool per_syllable = false,
hb_tag_t feature_tag = HB_TAG(' ',' ',' ',' '));
struct feature_info_t {
hb_tag_t tag;
unsigned int seq; /* sequence#, used for stable sorting only */
unsigned int max_value;
hb_ot_map_feature_flags_t flags;
unsigned int default_value; /* for non-global features, what should the unset glyphs take */
unsigned int stage[2]; /* GSUB/GPOS */
HB_INTERNAL static int cmp (const void *pa, const void *pb)
{
const feature_info_t *a = (const feature_info_t *) pa;
const feature_info_t *b = (const feature_info_t *) pb;
return (a->tag != b->tag) ? (a->tag < b->tag ? -1 : 1) :
(a->seq < b->seq ? -1 : a->seq > b->seq ? 1 : 0);
}
};
struct stage_info_t {
unsigned int index;
hb_ot_map_t::pause_func_t pause_func;
};
HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func);
public:
hb_face_t *face;
hb_segment_properties_t props;
bool is_simple;
hb_tag_t chosen_script[2];
bool found_script[2];
unsigned int script_index[2], language_index[2];
private:
unsigned int current_stage[2]; /* GSUB/GPOS */
hb_vector_t<feature_info_t> feature_infos;
hb_vector_t<stage_info_t> stages[2]; /* GSUB/GPOS */
};
#endif /* HB_OT_MAP_HH */