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Diffstat (limited to 'thirdparty/harfbuzz/src/hb-bit-page.hh')
| -rw-r--r-- | thirdparty/harfbuzz/src/hb-bit-page.hh | 282 |
1 files changed, 282 insertions, 0 deletions
diff --git a/thirdparty/harfbuzz/src/hb-bit-page.hh b/thirdparty/harfbuzz/src/hb-bit-page.hh new file mode 100644 index 0000000000..95ae1b7bf9 --- /dev/null +++ b/thirdparty/harfbuzz/src/hb-bit-page.hh @@ -0,0 +1,282 @@ +/* + * 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 value) { if (value) 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 */ |