harfbuzz/src/hb-bimap.hh

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/*
* Copyright © 2019 Adobe 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.
*
* Adobe Author(s): Michiharu Ariza
*/
#ifndef HB_BIMAP_HH
#define HB_BIMAP_HH
#include "hb.hh"
#include "hb-map.hh"
/* Bi-directional map */
struct hb_bimap_t
{
void reset ()
{
forw_map.reset ();
back_map.reset ();
}
bool in_error () const { return forw_map.in_error () || back_map.in_error (); }
void set (hb_codepoint_t lhs, hb_codepoint_t rhs)
{
if (in_error ()) return;
if (unlikely (lhs == HB_MAP_VALUE_INVALID)) return;
if (unlikely (rhs == HB_MAP_VALUE_INVALID)) { del (lhs); return; }
forw_map.set (lhs, rhs);
if (in_error ()) return;
back_map.set (rhs, lhs);
if (in_error ()) forw_map.del (lhs);
}
hb_codepoint_t get (hb_codepoint_t lhs) const { return forw_map.get (lhs); }
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hb_codepoint_t backward (hb_codepoint_t rhs) const { return back_map.get (rhs); }
hb_codepoint_t operator [] (hb_codepoint_t lhs) const { return get (lhs); }
bool has (hb_codepoint_t lhs, hb_codepoint_t *vp = nullptr) const { return forw_map.has (lhs, vp); }
void del (hb_codepoint_t lhs)
{
back_map.del (get (lhs));
forw_map.del (lhs);
}
void clear ()
{
forw_map.clear ();
back_map.clear ();
}
bool is_empty () const { return get_population () == 0; }
unsigned int get_population () const { return forw_map.get_population (); }
protected:
hb_map_t forw_map;
hb_map_t back_map;
};
/* Inremental bimap: only lhs is given, rhs is incrementally assigned */
struct hb_inc_bimap_t : hb_bimap_t
{
/* Add a mapping from lhs to rhs with a unique value if lhs is unknown.
* Return the rhs value as the result.
*/
hb_codepoint_t add (hb_codepoint_t lhs)
{
hb_codepoint_t rhs = forw_map[lhs];
if (rhs == HB_MAP_VALUE_INVALID)
{
rhs = next_value++;
set (lhs, rhs);
}
return rhs;
}
hb_codepoint_t skip ()
{ return next_value++; }
hb_codepoint_t get_next_value () const
{ return next_value; }
void add_set (const hb_set_t *set)
{
hb_codepoint_t i = HB_SET_VALUE_INVALID;
while (hb_set_next (set, &i)) add (i);
}
/* Create an identity map. */
bool identity (unsigned int size)
{
clear ();
for (hb_codepoint_t i = 0; i < size; i++) set (i, i);
return !in_error ();
}
protected:
static int cmp_id (const void* a, const void* b)
{ return (int)*(const hb_codepoint_t *)a - (int)*(const hb_codepoint_t *)b; }
public:
/* Optional: after finished adding all mappings in a random order,
* reassign rhs to lhs so that they are in the same order. */
void sort ()
{
hb_codepoint_t count = get_population ();
hb_vector_t <hb_codepoint_t> work;
work.resize (count);
for (hb_codepoint_t rhs = 0; rhs < count; rhs++)
work[rhs] = back_map[rhs];
work.qsort (cmp_id);
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clear ();
for (hb_codepoint_t rhs = 0; rhs < count; rhs++)
set (work[rhs], rhs);
}
protected:
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unsigned int next_value = 0;
};
#endif /* HB_BIMAP_HH */