283 lines
8.0 KiB
C++
283 lines
8.0 KiB
C++
/*
|
|
* Copyright © 2012,2017 Google, Inc.
|
|
* Copyright © 2021 Behdad Esfahbod
|
|
*
|
|
* 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
|
|
*/
|
|
|
|
#ifndef HB_BIT_PAGE_HH
|
|
#define HB_BIT_PAGE_HH
|
|
|
|
#include "hb.hh"
|
|
|
|
struct hb_bit_page_t
|
|
{
|
|
void init0 () { v.clear (); }
|
|
void init1 () { v.clear (0xFF); }
|
|
|
|
constexpr unsigned len () const
|
|
{ return ARRAY_LENGTH_CONST (v); }
|
|
|
|
bool is_empty () const
|
|
{
|
|
for (unsigned i = 0; i < len (); i++)
|
|
if (v[i])
|
|
return false;
|
|
return true;
|
|
}
|
|
uint32_t hash () const
|
|
{
|
|
uint32_t h = 0;
|
|
for (unsigned i = 0; i < len (); i++)
|
|
h = h * 31 + hb_hash (v[i]);
|
|
return h;
|
|
}
|
|
|
|
void add (hb_codepoint_t g) { elt (g) |= mask (g); }
|
|
void del (hb_codepoint_t g) { elt (g) &= ~mask (g); }
|
|
void set (hb_codepoint_t g, bool v) { if (v) add (g); else del (g); }
|
|
bool get (hb_codepoint_t g) const { return elt (g) & mask (g); }
|
|
|
|
void add_range (hb_codepoint_t a, hb_codepoint_t b)
|
|
{
|
|
elt_t *la = &elt (a);
|
|
elt_t *lb = &elt (b);
|
|
if (la == lb)
|
|
*la |= (mask (b) << 1) - mask(a);
|
|
else
|
|
{
|
|
*la |= ~(mask (a) - 1);
|
|
la++;
|
|
|
|
memset (la, 0xff, (char *) lb - (char *) la);
|
|
|
|
*lb |= ((mask (b) << 1) - 1);
|
|
}
|
|
}
|
|
void del_range (hb_codepoint_t a, hb_codepoint_t b)
|
|
{
|
|
elt_t *la = &elt (a);
|
|
elt_t *lb = &elt (b);
|
|
if (la == lb)
|
|
*la &= ~((mask (b) << 1) - mask(a));
|
|
else
|
|
{
|
|
*la &= mask (a) - 1;
|
|
la++;
|
|
|
|
memset (la, 0, (char *) lb - (char *) la);
|
|
|
|
*lb &= ~((mask (b) << 1) - 1);
|
|
}
|
|
}
|
|
void set_range (hb_codepoint_t a, hb_codepoint_t b, bool v)
|
|
{ if (v) add_range (a, b); else del_range (a, b); }
|
|
|
|
|
|
// Writes out page values to the array p. Returns the number of values
|
|
// written. At most size codepoints will be written.
|
|
unsigned int write (uint32_t base,
|
|
unsigned int start_value,
|
|
hb_codepoint_t *p,
|
|
unsigned int size) const
|
|
{
|
|
unsigned int start_v = start_value >> ELT_BITS_LOG_2;
|
|
unsigned int start_bit = start_value & ELT_MASK;
|
|
unsigned int count = 0;
|
|
for (unsigned i = start_v; i < len () && count < size; i++)
|
|
{
|
|
elt_t bits = v[i];
|
|
uint32_t v_base = base | (i << ELT_BITS_LOG_2);
|
|
for (unsigned int j = start_bit; j < ELT_BITS && count < size; j++)
|
|
{
|
|
if ((elt_t(1) << j) & bits) {
|
|
*p++ = v_base | j;
|
|
count++;
|
|
}
|
|
}
|
|
start_bit = 0;
|
|
}
|
|
return count;
|
|
}
|
|
|
|
// Writes out the values NOT in this page to the array p. Returns the
|
|
// number of values written. At most size codepoints will be written.
|
|
// Returns the number of codepoints written. next_value holds the next value
|
|
// that should be written (if not present in this page). This is used to fill
|
|
// any missing value gaps between this page and the previous page, if any.
|
|
// next_value is updated to one more than the last value present in this page.
|
|
unsigned int write_inverted (uint32_t base,
|
|
unsigned int start_value,
|
|
hb_codepoint_t *p,
|
|
unsigned int size,
|
|
hb_codepoint_t *next_value) const
|
|
{
|
|
unsigned int start_v = start_value >> ELT_BITS_LOG_2;
|
|
unsigned int start_bit = start_value & ELT_MASK;
|
|
unsigned int count = 0;
|
|
for (unsigned i = start_v; i < len () && count < size; i++)
|
|
{
|
|
elt_t bits = v[i];
|
|
uint32_t v_offset = i << ELT_BITS_LOG_2;
|
|
for (unsigned int j = start_bit; j < ELT_BITS && count < size; j++)
|
|
{
|
|
if ((elt_t(1) << j) & bits)
|
|
{
|
|
hb_codepoint_t value = base | v_offset | j;
|
|
// Emit all the missing values from next_value up to value - 1.
|
|
for (hb_codepoint_t k = *next_value; k < value && count < size; k++)
|
|
{
|
|
*p++ = k;
|
|
count++;
|
|
}
|
|
// Skip over this value;
|
|
*next_value = value + 1;
|
|
}
|
|
}
|
|
start_bit = 0;
|
|
}
|
|
return count;
|
|
}
|
|
|
|
bool is_equal (const hb_bit_page_t &other) const
|
|
{
|
|
return 0 == hb_memcmp (&v, &other.v, sizeof (v));
|
|
}
|
|
bool is_subset (const hb_bit_page_t &larger_page) const
|
|
{
|
|
for (unsigned i = 0; i < len (); i++)
|
|
if (~larger_page.v[i] & v[i])
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
unsigned int get_population () const
|
|
{
|
|
unsigned int pop = 0;
|
|
for (unsigned int i = 0; i < len (); i++)
|
|
pop += hb_popcount (v[i]);
|
|
return pop;
|
|
}
|
|
|
|
bool next (hb_codepoint_t *codepoint) const
|
|
{
|
|
unsigned int m = (*codepoint + 1) & MASK;
|
|
if (!m)
|
|
{
|
|
*codepoint = INVALID;
|
|
return false;
|
|
}
|
|
unsigned int i = m / ELT_BITS;
|
|
unsigned int j = m & ELT_MASK;
|
|
|
|
const elt_t vv = v[i] & ~((elt_t (1) << j) - 1);
|
|
for (const elt_t *p = &vv; i < len (); p = &v[++i])
|
|
if (*p)
|
|
{
|
|
*codepoint = i * ELT_BITS + elt_get_min (*p);
|
|
return true;
|
|
}
|
|
|
|
*codepoint = INVALID;
|
|
return false;
|
|
}
|
|
bool previous (hb_codepoint_t *codepoint) const
|
|
{
|
|
unsigned int m = (*codepoint - 1) & MASK;
|
|
if (m == MASK)
|
|
{
|
|
*codepoint = INVALID;
|
|
return false;
|
|
}
|
|
unsigned int i = m / ELT_BITS;
|
|
unsigned int j = m & ELT_MASK;
|
|
|
|
/* Fancy mask to avoid shifting by elt_t bitsize, which is undefined. */
|
|
const elt_t mask = j < 8 * sizeof (elt_t) - 1 ?
|
|
((elt_t (1) << (j + 1)) - 1) :
|
|
(elt_t) -1;
|
|
const elt_t vv = v[i] & mask;
|
|
const elt_t *p = &vv;
|
|
while (true)
|
|
{
|
|
if (*p)
|
|
{
|
|
*codepoint = i * ELT_BITS + elt_get_max (*p);
|
|
return true;
|
|
}
|
|
if ((int) i <= 0) break;
|
|
p = &v[--i];
|
|
}
|
|
|
|
*codepoint = INVALID;
|
|
return false;
|
|
}
|
|
hb_codepoint_t get_min () const
|
|
{
|
|
for (unsigned int i = 0; i < len (); i++)
|
|
if (v[i])
|
|
return i * ELT_BITS + elt_get_min (v[i]);
|
|
return INVALID;
|
|
}
|
|
hb_codepoint_t get_max () const
|
|
{
|
|
for (int i = len () - 1; i >= 0; i--)
|
|
if (v[i])
|
|
return i * ELT_BITS + elt_get_max (v[i]);
|
|
return 0;
|
|
}
|
|
|
|
static constexpr hb_codepoint_t INVALID = HB_SET_VALUE_INVALID;
|
|
|
|
typedef unsigned long long elt_t;
|
|
static constexpr unsigned PAGE_BITS = 512;
|
|
static_assert ((PAGE_BITS & ((PAGE_BITS) - 1)) == 0, "");
|
|
static constexpr unsigned PAGE_BITS_LOG_2 = 9;
|
|
static_assert (1 << PAGE_BITS_LOG_2 == PAGE_BITS, "");
|
|
static constexpr unsigned PAGE_BITMASK = PAGE_BITS - 1;
|
|
|
|
static unsigned int elt_get_min (const elt_t &elt) { return hb_ctz (elt); }
|
|
static unsigned int elt_get_max (const elt_t &elt) { return hb_bit_storage (elt) - 1; }
|
|
|
|
typedef hb_vector_size_t<elt_t, PAGE_BITS / 8> vector_t;
|
|
|
|
static constexpr unsigned ELT_BITS = sizeof (elt_t) * 8;
|
|
static constexpr unsigned ELT_BITS_LOG_2 = 6;
|
|
static_assert (1 << ELT_BITS_LOG_2 == ELT_BITS, "");
|
|
static constexpr unsigned ELT_MASK = ELT_BITS - 1;
|
|
|
|
static constexpr unsigned BITS = sizeof (vector_t) * 8;
|
|
static constexpr unsigned MASK = BITS - 1;
|
|
static_assert ((unsigned) PAGE_BITS == (unsigned) BITS, "");
|
|
|
|
elt_t &elt (hb_codepoint_t g) { return v[(g & MASK) / ELT_BITS]; }
|
|
const elt_t& elt (hb_codepoint_t g) const { return v[(g & MASK) / ELT_BITS]; }
|
|
static constexpr elt_t mask (hb_codepoint_t g) { return elt_t (1) << (g & ELT_MASK); }
|
|
|
|
vector_t v;
|
|
};
|
|
static_assert (hb_bit_page_t::PAGE_BITS == sizeof (hb_bit_page_t) * 8, "");
|
|
|
|
|
|
#endif /* HB_BIT_PAGE_HH */
|