--- /dev/null
+/*
+ * 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_DIGEST_PRIVATE_HH
+#define HB_SET_DIGEST_PRIVATE_HH
+
+#include "hb-private.hh"
+
+/*
+ * The set digests here implement various "filters" that support
+ * "approximate member query". Conceptually these are like Bloom
+ * Filter and Quotient Filter, however, much smaller, faster, and
+ * designed to fit the requirements of our uses for glyph coverage
+ * queries.
+ *
+ * Our filters are highly accurate if the lookup covers fairly local
+ * set of glyphs, but fully flooded and ineffective if coverage is
+ * all over the place.
+ *
+ * The frozen-set can be used instead of a digest, to trade more
+ * memory for 100% accuracy, but in practice, that doesn't look like
+ * an attractive trade-off.
+ */
+
+template <typename mask_t, unsigned int shift>
+struct hb_set_digest_lowest_bits_t
+{
+ ASSERT_POD ();
+
+ static const unsigned int mask_bytes = sizeof (mask_t);
+ static const unsigned int mask_bits = sizeof (mask_t) * 8;
+ static const unsigned int num_bits = 0
+ + (mask_bytes >= 1 ? 3 : 0)
+ + (mask_bytes >= 2 ? 1 : 0)
+ + (mask_bytes >= 4 ? 1 : 0)
+ + (mask_bytes >= 8 ? 1 : 0)
+ + (mask_bytes >= 16? 1 : 0)
+ + 0;
+
+ static_assert ((shift < sizeof (hb_codepoint_t) * 8), "");
+ static_assert ((shift + num_bits <= sizeof (hb_codepoint_t) * 8), "");
+
+ 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 >> shift) - (a >> shift) >= mask_bits - 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:
+
+ static inline mask_t mask_for (hb_codepoint_t g) {
+ return ((mask_t) 1) << ((g >> shift) & (mask_bits - 1));
+ }
+ mask_t mask;
+};
+
+template <typename head_t, typename tail_t>
+struct hb_set_digest_combiner_t
+{
+ ASSERT_POD ();
+
+ inline void init (void) {
+ head.init ();
+ tail.init ();
+ }
+
+ inline void add (hb_codepoint_t g) {
+ head.add (g);
+ tail.add (g);
+ }
+
+ inline void add_range (hb_codepoint_t a, hb_codepoint_t b) {
+ head.add_range (a, b);
+ tail.add_range (a, b);
+ }
+
+ inline bool may_have (hb_codepoint_t g) const {
+ return head.may_have (g) && tail.may_have (g);
+ }
+
+ private:
+ head_t head;
+ tail_t tail;
+};
+
+
+/*
+ * hb_set_digest_t
+ *
+ * This is a combination of digests that performs "best".
+ * There is not much science to this: it's a result of intuition
+ * and testing.
+ */
+typedef hb_set_digest_combiner_t
+<
+ hb_set_digest_lowest_bits_t<unsigned long, 4>,
+ hb_set_digest_combiner_t
+ <
+ hb_set_digest_lowest_bits_t<unsigned long, 0>,
+ hb_set_digest_lowest_bits_t<unsigned long, 9>
+ >
+> hb_set_digest_t;
+
+
+#endif /* HB_SET_DIGEST_PRIVATE_HH */
/*
- * The set digests here implement various "filters" that support
- * "approximate member query". Conceptually these are like Bloom
- * Filter and Quotient Filter, however, much smaller, faster, and
- * designed to fit the requirements of our uses for glyph coverage
- * queries.
- *
- * Our filters are highly accurate if the lookup covers fairly local
- * set of glyphs, but fully flooded and ineffective if coverage is
- * all over the place.
- *
- * The frozen-set can be used instead of a digest, to trade more
- * memory for 100% accuracy, but in practice, that doesn't look like
- * an attractive trade-off.
- */
-
-template <typename mask_t, unsigned int shift>
-struct hb_set_digest_lowest_bits_t
-{
- ASSERT_POD ();
-
- static const unsigned int mask_bytes = sizeof (mask_t);
- static const unsigned int mask_bits = sizeof (mask_t) * 8;
- static const unsigned int num_bits = 0
- + (mask_bytes >= 1 ? 3 : 0)
- + (mask_bytes >= 2 ? 1 : 0)
- + (mask_bytes >= 4 ? 1 : 0)
- + (mask_bytes >= 8 ? 1 : 0)
- + (mask_bytes >= 16? 1 : 0)
- + 0;
-
- static_assert ((shift < sizeof (hb_codepoint_t) * 8), "");
- static_assert ((shift + num_bits <= sizeof (hb_codepoint_t) * 8), "");
-
- 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 >> shift) - (a >> shift) >= mask_bits - 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:
-
- static inline mask_t mask_for (hb_codepoint_t g) {
- return ((mask_t) 1) << ((g >> shift) & (mask_bits - 1));
- }
- mask_t mask;
-};
-
-template <typename head_t, typename tail_t>
-struct hb_set_digest_combiner_t
-{
- ASSERT_POD ();
-
- inline void init (void) {
- head.init ();
- tail.init ();
- }
-
- inline void add (hb_codepoint_t g) {
- head.add (g);
- tail.add (g);
- }
-
- inline void add_range (hb_codepoint_t a, hb_codepoint_t b) {
- head.add_range (a, b);
- tail.add_range (a, b);
- }
-
- inline bool may_have (hb_codepoint_t g) const {
- return head.may_have (g) && tail.may_have (g);
- }
-
- private:
- head_t head;
- tail_t tail;
-};
-
-
-/*
- * hb_set_digest_t
- *
- * This is a combination of digests that performs "best".
- * There is not much science to this: it's a result of intuition
- * and testing.
- */
-typedef hb_set_digest_combiner_t
-<
- hb_set_digest_lowest_bits_t<unsigned long, 4>,
- hb_set_digest_combiner_t
- <
- hb_set_digest_lowest_bits_t<unsigned long, 0>,
- hb_set_digest_lowest_bits_t<unsigned long, 9>
- >
-> hb_set_digest_t;
-
-
-
-/*
* hb_set_t
*/
projects / platform / upstream / libHarfBuzzSharp.git / commitdiff