/* * Copyright © 2012 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. * * Google Author(s): Behdad Esfahbod */ #ifndef HB_SET_PRIVATE_HH #define HB_SET_PRIVATE_HH #include "hb-private.hh" #include "hb-set.h" #include "hb-object-private.hh" struct hb_set_digest_common_bits_t { ASSERT_POD (); typedef unsigned int mask_t; inline void init (void) { mask = ~0; value = (mask_t) -1; } inline void add (hb_codepoint_t g) { if (unlikely (value == (mask_t) -1)) { value = g; return; } mask ^= (g & mask) ^ value; value &= mask; } inline void add_range (hb_codepoint_t a, hb_codepoint_t b) { /* The negation here stands for ~(x-1). */ mask &= -(1 << _hb_bit_storage (a ^ b)); value &= mask; } inline bool may_have (hb_codepoint_t g) const { return (g & mask) == value; } private: mask_t mask; mask_t value; }; struct hb_set_digest_lowest_bits_t { ASSERT_POD (); typedef unsigned long mask_t; inline void init (void) { mask = 0; } inline void add (hb_codepoint_t g) { mask |= mask_for (g); } inline void add_range (hb_codepoint_t a, hb_codepoint_t b) { if (b - a >= sizeof (mask_t) * 8 - 1) mask = (mask_t) -1; else { mask_t ma = mask_for (a); mask_t mb = mask_for (b); mask |= mb + (mb - ma) - (mb < ma); } } inline bool may_have (hb_codepoint_t g) const { return !!(mask & mask_for (g)); } private: mask_t mask_for (hb_codepoint_t g) const { return ((mask_t) 1) << (g & (sizeof (mask_t) * 8 - 1)); } mask_t mask; }; struct hb_set_digest_t { ASSERT_POD (); inline void init (void) { digest1.init (); digest2.init (); } inline void add (hb_codepoint_t g) { digest1.add (g); digest2.add (g); } inline void add_range (hb_codepoint_t a, hb_codepoint_t b) { digest1.add_range (a, b); digest2.add_range (a, b); } inline bool may_have (hb_codepoint_t g) const { return digest1.may_have (g) && digest2.may_have (g); } private: hb_set_digest_common_bits_t digest1; hb_set_digest_lowest_bits_t digest2; }; /* TODO Make this faster and memmory efficient. */ struct hb_set_t { hb_object_header_t header; ASSERT_POD (); inline void init (void) { header.init (); clear (); } inline void fini (void) { } inline void clear (void) { memset (elts, 0, sizeof elts); } inline bool empty (void) const { for (unsigned int i = 0; i < ARRAY_LENGTH (elts); i++) if (elts[i]) return false; return true; } inline void add (hb_codepoint_t g) { if (unlikely (g == SENTINEL)) return; if (unlikely (g > MAX_G)) return; elt (g) |= mask (g); } inline void add_range (hb_codepoint_t a, hb_codepoint_t b) { for (unsigned int i = a; i < b + 1; i++) add (i); } inline void del (hb_codepoint_t g) { if (unlikely (g > MAX_G)) return; elt (g) &= ~mask (g); } inline bool has (hb_codepoint_t g) const { if (unlikely (g > MAX_G)) return false; return !!(elt (g) & mask (g)); } inline bool intersects (hb_codepoint_t first, hb_codepoint_t last) const { if (unlikely (first > MAX_G)) return false; if (unlikely (last > MAX_G)) last = MAX_G; unsigned int end = last + 1; for (hb_codepoint_t i = first; i < end; i++) if (has (i)) return true; return false; } inline bool equal (const hb_set_t *other) const { for (unsigned int i = 0; i < ELTS; i++) if (elts[i] != other->elts[i]) return false; return true; } inline void set (const hb_set_t *other) { for (unsigned int i = 0; i < ELTS; i++) elts[i] = other->elts[i]; } inline void union_ (const hb_set_t *other) { for (unsigned int i = 0; i < ELTS; i++) elts[i] |= other->elts[i]; } inline void intersect (const hb_set_t *other) { for (unsigned int i = 0; i < ELTS; i++) elts[i] &= other->elts[i]; } inline void subtract (const hb_set_t *other) { for (unsigned int i = 0; i < ELTS; i++) elts[i] &= ~other->elts[i]; } inline void symmetric_difference (const hb_set_t *other) { for (unsigned int i = 0; i < ELTS; i++) elts[i] ^= other->elts[i]; } inline bool next (hb_codepoint_t *codepoint) { if (unlikely (*codepoint == SENTINEL)) { hb_codepoint_t i = get_min (); if (i != SENTINEL) { *codepoint = i; return true; } else return false; } for (hb_codepoint_t i = *codepoint + 1; i < MAX_G + 1; i++) if (has (i)) { *codepoint = i; return true; } return false; } inline hb_codepoint_t get_min (void) const { for (unsigned int i = 0; i < ELTS; i++) if (elts[i]) for (unsigned int j = 0; i < BITS; j++) if (elts[i] & (1 << j)) return i * BITS + j; return SENTINEL; } inline hb_codepoint_t get_max (void) const { for (unsigned int i = ELTS; i; i--) if (elts[i - 1]) for (unsigned int j = BITS; j; j--) if (elts[i - 1] & (1 << (j - 1))) return (i - 1) * BITS + (j - 1); return SENTINEL; } typedef uint32_t elt_t; static const unsigned int MAX_G = 65536 - 1; /* XXX Fix this... */ static const unsigned int SHIFT = 5; static const unsigned int BITS = (1 << SHIFT); static const unsigned int MASK = BITS - 1; static const unsigned int ELTS = (MAX_G + 1 + (BITS - 1)) / BITS; static const hb_codepoint_t SENTINEL = (hb_codepoint_t) -1; elt_t &elt (hb_codepoint_t g) { return elts[g >> SHIFT]; } elt_t elt (hb_codepoint_t g) const { return elts[g >> SHIFT]; } elt_t mask (hb_codepoint_t g) const { return elt_t (1) << (g & MASK); } elt_t elts[ELTS]; /* XXX 8kb */ ASSERT_STATIC (sizeof (elt_t) * 8 == BITS); ASSERT_STATIC (sizeof (elt_t) * 8 * ELTS > MAX_G); }; #endif /* HB_SET_PRIVATE_HH */