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Diffstat (limited to 'gfx/harfbuzz/src/hb-algs.hh')
| -rw-r--r-- | gfx/harfbuzz/src/hb-algs.hh | 1542 |
1 files changed, 1542 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-algs.hh b/gfx/harfbuzz/src/hb-algs.hh new file mode 100644 index 0000000000..ea97057165 --- /dev/null +++ b/gfx/harfbuzz/src/hb-algs.hh @@ -0,0 +1,1542 @@ +/* + * Copyright © 2017 Google, Inc. + * Copyright © 2019 Facebook, 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 + * Facebook Author(s): Behdad Esfahbod + */ + +#ifndef HB_ALGS_HH +#define HB_ALGS_HH + +#include "hb.hh" +#include "hb-meta.hh" +#include "hb-null.hh" +#include "hb-number.hh" + +#include <algorithm> +#include <initializer_list> +#include <functional> +#include <new> + +/* + * Flags + */ + +/* Enable bitwise ops on enums marked as flags_t */ +/* To my surprise, looks like the function resolver is happy to silently cast + * one enum to another... So this doesn't provide the type-checking that I + * originally had in mind... :(. + * + * For MSVC warnings, see: https://github.com/harfbuzz/harfbuzz/pull/163 + */ +#ifdef _MSC_VER +# pragma warning(disable:4200) +# pragma warning(disable:4800) +#endif +#define HB_MARK_AS_FLAG_T(T) \ + extern "C++" { \ + static inline constexpr T operator | (T l, T r) { return T ((unsigned) l | (unsigned) r); } \ + static inline constexpr T operator & (T l, T r) { return T ((unsigned) l & (unsigned) r); } \ + static inline constexpr T operator ^ (T l, T r) { return T ((unsigned) l ^ (unsigned) r); } \ + static inline constexpr unsigned operator ~ (T r) { return (~(unsigned) r); } \ + static inline T& operator |= (T &l, T r) { l = l | r; return l; } \ + static inline T& operator &= (T& l, T r) { l = l & r; return l; } \ + static inline T& operator ^= (T& l, T r) { l = l ^ r; return l; } \ + } \ + static_assert (true, "") + +/* Useful for set-operations on small enums. + * For example, for testing "x ∈ {x1, x2, x3}" use: + * (FLAG_UNSAFE(x) & (FLAG(x1) | FLAG(x2) | FLAG(x3))) + */ +#define FLAG(x) (static_assert_expr ((unsigned)(x) < 32) + (((uint32_t) 1U) << (unsigned)(x))) +#define FLAG_UNSAFE(x) ((unsigned)(x) < 32 ? (((uint32_t) 1U) << (unsigned)(x)) : 0) +#define FLAG_RANGE(x,y) (static_assert_expr ((x) < (y)) + FLAG(y+1) - FLAG(x)) +#define FLAG64(x) (static_assert_expr ((unsigned)(x) < 64) + (((uint64_t) 1ULL) << (unsigned)(x))) +#define FLAG64_UNSAFE(x) ((unsigned)(x) < 64 ? (((uint64_t) 1ULL) << (unsigned)(x)) : 0) + + +/* + * Big-endian integers. + */ + +/* Endian swap, used in Windows related backends */ +static inline constexpr uint16_t hb_uint16_swap (uint16_t v) +{ return (v >> 8) | (v << 8); } +static inline constexpr uint32_t hb_uint32_swap (uint32_t v) +{ return (hb_uint16_swap (v) << 16) | hb_uint16_swap (v >> 16); } + +#ifndef HB_FAST_INT_ACCESS +#if defined(__OPTIMIZE__) && \ + defined(__BYTE_ORDER) && \ + (__BYTE_ORDER == __BIG_ENDIAN || \ + (__BYTE_ORDER == __LITTLE_ENDIAN && \ + hb_has_builtin(__builtin_bswap16) && \ + hb_has_builtin(__builtin_bswap32))) +#define HB_FAST_INT_ACCESS 1 +#else +#define HB_FAST_INT_ACCESS 0 +#endif +#endif + +template <typename Type, int Bytes = sizeof (Type)> +struct BEInt; +template <typename Type> +struct BEInt<Type, 1> +{ + public: + BEInt () = default; + constexpr BEInt (Type V) : v {uint8_t (V)} {} + constexpr operator Type () const { return v; } + private: uint8_t v; +}; +template <typename Type> +struct BEInt<Type, 2> +{ + struct __attribute__((packed)) packed_uint16_t { uint16_t v; }; + + public: + BEInt () = default; + + BEInt (Type V) +#if HB_FAST_INT_ACCESS +#if __BYTE_ORDER == __LITTLE_ENDIAN + { ((packed_uint16_t *) v)->v = __builtin_bswap16 (V); } +#else /* __BYTE_ORDER == __BIG_ENDIAN */ + { ((packed_uint16_t *) v)->v = V; } +#endif +#else + : v {uint8_t ((V >> 8) & 0xFF), + uint8_t ((V ) & 0xFF)} {} +#endif + + constexpr operator Type () const { +#if HB_FAST_INT_ACCESS +#if __BYTE_ORDER == __LITTLE_ENDIAN + return __builtin_bswap16 (((packed_uint16_t *) v)->v); +#else /* __BYTE_ORDER == __BIG_ENDIAN */ + return ((packed_uint16_t *) v)->v; +#endif +#else + return (v[0] << 8) + + (v[1] ); +#endif + } + private: uint8_t v[2]; +}; +template <typename Type> +struct BEInt<Type, 3> +{ + static_assert (!std::is_signed<Type>::value, ""); + public: + BEInt () = default; + constexpr BEInt (Type V) : v {uint8_t ((V >> 16) & 0xFF), + uint8_t ((V >> 8) & 0xFF), + uint8_t ((V ) & 0xFF)} {} + + constexpr operator Type () const { return (v[0] << 16) + + (v[1] << 8) + + (v[2] ); } + private: uint8_t v[3]; +}; +template <typename Type> +struct BEInt<Type, 4> +{ + struct __attribute__((packed)) packed_uint32_t { uint32_t v; }; + + public: + BEInt () = default; + + BEInt (Type V) +#if HB_FAST_INT_ACCESS +#if __BYTE_ORDER == __LITTLE_ENDIAN + { ((packed_uint32_t *) v)->v = __builtin_bswap32 (V); } +#else /* __BYTE_ORDER == __BIG_ENDIAN */ + { ((packed_uint32_t *) v)->v = V; } +#endif +#else + : v {uint8_t ((V >> 24) & 0xFF), + uint8_t ((V >> 16) & 0xFF), + uint8_t ((V >> 8) & 0xFF), + uint8_t ((V ) & 0xFF)} {} +#endif + + constexpr operator Type () const { +#if HB_FAST_INT_ACCESS +#if __BYTE_ORDER == __LITTLE_ENDIAN + return __builtin_bswap32 (((packed_uint32_t *) v)->v); +#else /* __BYTE_ORDER == __BIG_ENDIAN */ + return ((packed_uint32_t *) v)->v; +#endif +#else + return (v[0] << 24) + + (v[1] << 16) + + (v[2] << 8) + + (v[3] ); +#endif + } + private: uint8_t v[4]; +}; + +/* Floats. */ + +/* We want our rounding towards +infinity. */ +static inline float +_hb_roundf (float x) { return floorf (x + .5f); } +#define roundf(x) _hb_roundf(x) + + +/* Encodes three unsigned integers in one 64-bit number. If the inputs have more than 21 bits, + * values will be truncated / overlap, and might not decode exactly. */ +#define HB_CODEPOINT_ENCODE3(x,y,z) (((uint64_t) (x) << 42) | ((uint64_t) (y) << 21) | (uint64_t) (z)) +#define HB_CODEPOINT_DECODE3_1(v) ((hb_codepoint_t) ((v) >> 42)) +#define HB_CODEPOINT_DECODE3_2(v) ((hb_codepoint_t) ((v) >> 21) & 0x1FFFFFu) +#define HB_CODEPOINT_DECODE3_3(v) ((hb_codepoint_t) (v) & 0x1FFFFFu) + +/* Custom encoding used by hb-ucd. */ +#define HB_CODEPOINT_ENCODE3_11_7_14(x,y,z) (((uint32_t) ((x) & 0x07FFu) << 21) | (((uint32_t) (y) & 0x007Fu) << 14) | (uint32_t) ((z) & 0x3FFFu)) +#define HB_CODEPOINT_DECODE3_11_7_14_1(v) ((hb_codepoint_t) ((v) >> 21)) +#define HB_CODEPOINT_DECODE3_11_7_14_2(v) ((hb_codepoint_t) (((v) >> 14) & 0x007Fu) | 0x0300) +#define HB_CODEPOINT_DECODE3_11_7_14_3(v) ((hb_codepoint_t) (v) & 0x3FFFu) + + +struct +{ + /* Note. This is dangerous in that if it's passed an rvalue, it returns rvalue-reference. */ + template <typename T> constexpr auto + operator () (T&& v) const HB_AUTO_RETURN ( std::forward<T> (v) ) +} +HB_FUNCOBJ (hb_identity); +struct +{ + /* Like identity(), but only retains lvalue-references. Rvalues are returned as rvalues. */ + template <typename T> constexpr T& + operator () (T& v) const { return v; } + + template <typename T> constexpr hb_remove_reference<T> + operator () (T&& v) const { return v; } +} +HB_FUNCOBJ (hb_lidentity); +struct +{ + /* Like identity(), but always returns rvalue. */ + template <typename T> constexpr hb_remove_reference<T> + operator () (T&& v) const { return v; } +} +HB_FUNCOBJ (hb_ridentity); + +struct +{ + template <typename T> constexpr bool + operator () (T&& v) const { return bool (std::forward<T> (v)); } +} +HB_FUNCOBJ (hb_bool); + + +/* The MIT License + + Copyright (C) 2012 Zilong Tan (eric.zltan@gmail.com) + + Permission is hereby granted, free of charge, to any person + obtaining a copy of this software and associated documentation + files (the "Software"), to deal in the Software without + restriction, including without limitation the rights to use, copy, + modify, merge, publish, distribute, sublicense, and/or sell copies + of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be + included in all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + SOFTWARE. +*/ + + +// Compression function for Merkle-Damgard construction. +// This function is generated using the framework provided. +#define mix(h) ( \ + (void) ((h) ^= (h) >> 23), \ + (void) ((h) *= 0x2127599bf4325c37ULL), \ + (h) ^= (h) >> 47) + +static inline uint64_t fasthash64(const void *buf, size_t len, uint64_t seed) +{ + struct __attribute__((packed)) packed_uint64_t { uint64_t v; }; + const uint64_t m = 0x880355f21e6d1965ULL; + const packed_uint64_t *pos = (const packed_uint64_t *)buf; + const packed_uint64_t *end = pos + (len / 8); + const unsigned char *pos2; + uint64_t h = seed ^ (len * m); + uint64_t v; + +#ifndef HB_OPTIMIZE_SIZE + if (((uintptr_t) pos & 7) == 0) + { + while (pos != end) + { +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wcast-align" + v = * (const uint64_t *) (pos++); +#pragma GCC diagnostic pop + h ^= mix(v); + h *= m; + } + } + else +#endif + { + while (pos != end) + { + v = pos++->v; + h ^= mix(v); + h *= m; + } + } + + pos2 = (const unsigned char*)pos; + v = 0; + + switch (len & 7) { + case 7: v ^= (uint64_t)pos2[6] << 48; HB_FALLTHROUGH; + case 6: v ^= (uint64_t)pos2[5] << 40; HB_FALLTHROUGH; + case 5: v ^= (uint64_t)pos2[4] << 32; HB_FALLTHROUGH; + case 4: v ^= (uint64_t)pos2[3] << 24; HB_FALLTHROUGH; + case 3: v ^= (uint64_t)pos2[2] << 16; HB_FALLTHROUGH; + case 2: v ^= (uint64_t)pos2[1] << 8; HB_FALLTHROUGH; + case 1: v ^= (uint64_t)pos2[0]; + h ^= mix(v); + h *= m; + } + + return mix(h); +} + +static inline uint32_t fasthash32(const void *buf, size_t len, uint32_t seed) +{ + // the following trick converts the 64-bit hashcode to Fermat + // residue, which shall retain information from both the higher + // and lower parts of hashcode. + uint64_t h = fasthash64(buf, len, seed); + return h - (h >> 32); +} + +struct +{ + private: + + template <typename T> constexpr auto + impl (const T& v, hb_priority<2>) const HB_RETURN (uint32_t, hb_deref (v).hash ()) + + // Horrible: std:hash() of integers seems to be identity in gcc / clang?! + // https://github.com/harfbuzz/harfbuzz/pull/4228 + // + // For performance characteristics see: + // https://github.com/harfbuzz/harfbuzz/pull/4228#issuecomment-1565079537 + template <typename T, + hb_enable_if (std::is_integral<T>::value && sizeof (T) <= sizeof (uint32_t))> constexpr auto + impl (const T& v, hb_priority<1>) const HB_RETURN (uint32_t, (uint32_t) v * 2654435761u /* Knuh's multiplicative hash */) + template <typename T, + hb_enable_if (std::is_integral<T>::value && sizeof (T) > sizeof (uint32_t))> constexpr auto + impl (const T& v, hb_priority<1>) const HB_RETURN (uint32_t, (uint32_t) (v ^ (v >> 32)) * 2654435761u /* Knuth's multiplicative hash */) + + template <typename T, + hb_enable_if (std::is_floating_point<T>::value)> constexpr auto + impl (const T& v, hb_priority<1>) const HB_RETURN (uint32_t, fasthash32 (std::addressof (v), sizeof (T), 0xf437ffe6)) + + template <typename T> constexpr auto + impl (const T& v, hb_priority<0>) const HB_RETURN (uint32_t, std::hash<hb_decay<decltype (hb_deref (v))>>{} (hb_deref (v))) + + public: + + template <typename T> constexpr auto + operator () (const T& v) const HB_RETURN (uint32_t, impl (v, hb_prioritize)) +} +HB_FUNCOBJ (hb_hash); + + +struct +{ + private: + + /* Pointer-to-member-function. */ + template <typename Appl, typename T, typename ...Ts> auto + impl (Appl&& a, hb_priority<2>, T &&v, Ts&&... ds) const HB_AUTO_RETURN + ((hb_deref (std::forward<T> (v)).*std::forward<Appl> (a)) (std::forward<Ts> (ds)...)) + + /* Pointer-to-member. */ + template <typename Appl, typename T> auto + impl (Appl&& a, hb_priority<1>, T &&v) const HB_AUTO_RETURN + ((hb_deref (std::forward<T> (v))).*std::forward<Appl> (a)) + + /* Operator(). */ + template <typename Appl, typename ...Ts> auto + impl (Appl&& a, hb_priority<0>, Ts&&... ds) const HB_AUTO_RETURN + (hb_deref (std::forward<Appl> (a)) (std::forward<Ts> (ds)...)) + + public: + + template <typename Appl, typename ...Ts> auto + operator () (Appl&& a, Ts&&... ds) const HB_AUTO_RETURN + ( + impl (std::forward<Appl> (a), + hb_prioritize, + std::forward<Ts> (ds)...) + ) +} +HB_FUNCOBJ (hb_invoke); + +template <unsigned Pos, typename Appl, typename V> +struct hb_partial_t +{ + hb_partial_t (Appl a, V v) : a (a), v (v) {} + + static_assert (Pos > 0, ""); + + template <typename ...Ts, + unsigned P = Pos, + hb_enable_if (P == 1)> auto + operator () (Ts&& ...ds) -> decltype (hb_invoke (hb_declval (Appl), + hb_declval (V), + hb_declval (Ts)...)) + { + return hb_invoke (std::forward<Appl> (a), + std::forward<V> (v), + std::forward<Ts> (ds)...); + } + template <typename T0, typename ...Ts, + unsigned P = Pos, + hb_enable_if (P == 2)> auto + operator () (T0&& d0, Ts&& ...ds) -> decltype (hb_invoke (hb_declval (Appl), + hb_declval (T0), + hb_declval (V), + hb_declval (Ts)...)) + { + return hb_invoke (std::forward<Appl> (a), + std::forward<T0> (d0), + std::forward<V> (v), + std::forward<Ts> (ds)...); + } + + private: + hb_reference_wrapper<Appl> a; + V v; +}; +template <unsigned Pos=1, typename Appl, typename V> +auto hb_partial (Appl&& a, V&& v) HB_AUTO_RETURN +(( hb_partial_t<Pos, Appl, V> (a, v) )) + +/* The following, HB_PARTIALIZE, macro uses a particular corner-case + * of C++11 that is not particularly well-supported by all compilers. + * What's happening is that it's using "this" in a trailing return-type + * via decltype(). Broken compilers deduce the type of "this" pointer + * in that context differently from what it resolves to in the body + * of the function. + * + * One probable cause of this is that at the time of trailing return + * type declaration, "this" points to an incomplete type, whereas in + * the function body the type is complete. That doesn't justify the + * error in any way, but is probably what's happening. + * + * In the case of MSVC, we get around this by using C++14 "decltype(auto)" + * which deduces the type from the actual return statement. For gcc 4.8 + * we use "+this" instead of "this" which produces an rvalue that seems + * to be deduced as the same type with this particular compiler, and seem + * to be fine as default code path as well. + */ +#ifdef _MSC_VER +/* https://github.com/harfbuzz/harfbuzz/issues/1730 */ \ +#define HB_PARTIALIZE(Pos) \ + template <typename _T> \ + decltype(auto) operator () (_T&& _v) const \ + { return hb_partial<Pos> (this, std::forward<_T> (_v)); } \ + static_assert (true, "") +#else +/* https://github.com/harfbuzz/harfbuzz/issues/1724 */ +#define HB_PARTIALIZE(Pos) \ + template <typename _T> \ + auto operator () (_T&& _v) const HB_AUTO_RETURN \ + (hb_partial<Pos> (+this, std::forward<_T> (_v))) \ + static_assert (true, "") +#endif + + +struct +{ + private: + + template <typename Pred, typename Val> auto + impl (Pred&& p, Val &&v, hb_priority<1>) const HB_AUTO_RETURN + ( + hb_deref (std::forward<Pred> (p)).has (std::forward<Val> (v)) + ) + + template <typename Pred, typename Val> auto + impl (Pred&& p, Val &&v, hb_priority<0>) const HB_AUTO_RETURN + ( + hb_invoke (std::forward<Pred> (p), + std::forward<Val> (v)) + ) + + public: + + template <typename Pred, typename Val> auto + operator () (Pred&& p, Val &&v) const HB_RETURN (bool, + impl (std::forward<Pred> (p), + std::forward<Val> (v), + hb_prioritize) + ) +} +HB_FUNCOBJ (hb_has); + +struct +{ + private: + + template <typename Pred, typename Val> auto + impl (Pred&& p, Val &&v, hb_priority<1>) const HB_AUTO_RETURN + ( + hb_has (std::forward<Pred> (p), + std::forward<Val> (v)) + ) + + template <typename Pred, typename Val> auto + impl (Pred&& p, Val &&v, hb_priority<0>) const HB_AUTO_RETURN + ( + std::forward<Pred> (p) == std::forward<Val> (v) + ) + + public: + + template <typename Pred, typename Val> auto + operator () (Pred&& p, Val &&v) const HB_RETURN (bool, + impl (std::forward<Pred> (p), + std::forward<Val> (v), + hb_prioritize) + ) +} +HB_FUNCOBJ (hb_match); + +struct +{ + private: + + template <typename Proj, typename Val> auto + impl (Proj&& f, Val &&v, hb_priority<2>) const HB_AUTO_RETURN + ( + hb_deref (std::forward<Proj> (f)).get (std::forward<Val> (v)) + ) + + template <typename Proj, typename Val> auto + impl (Proj&& f, Val &&v, hb_priority<1>) const HB_AUTO_RETURN + ( + hb_invoke (std::forward<Proj> (f), + std::forward<Val> (v)) + ) + + template <typename Proj, typename Val> auto + impl (Proj&& f, Val &&v, hb_priority<0>) const HB_AUTO_RETURN + ( + std::forward<Proj> (f)[std::forward<Val> (v)] + ) + + public: + + template <typename Proj, typename Val> auto + operator () (Proj&& f, Val &&v) const HB_AUTO_RETURN + ( + impl (std::forward<Proj> (f), + std::forward<Val> (v), + hb_prioritize) + ) +} +HB_FUNCOBJ (hb_get); + +struct +{ + private: + + template <typename T1, typename T2> auto + impl (T1&& v1, T2 &&v2, hb_priority<3>) const HB_AUTO_RETURN + ( + std::forward<T2> (v2).cmp (std::forward<T1> (v1)) == 0 + ) + + template <typename T1, typename T2> auto + impl (T1&& v1, T2 &&v2, hb_priority<2>) const HB_AUTO_RETURN + ( + std::forward<T1> (v1).cmp (std::forward<T2> (v2)) == 0 + ) + + template <typename T1, typename T2> auto + impl (T1&& v1, T2 &&v2, hb_priority<1>) const HB_AUTO_RETURN + ( + std::forward<T1> (v1) == std::forward<T2> (v2) + ) + + template <typename T1, typename T2> auto + impl (T1&& v1, T2 &&v2, hb_priority<0>) const HB_AUTO_RETURN + ( + std::forward<T2> (v2) == std::forward<T1> (v1) + ) + + public: + + template <typename T1, typename T2> auto + operator () (T1&& v1, T2 &&v2) const HB_AUTO_RETURN + ( + impl (std::forward<T1> (v1), + std::forward<T2> (v2), + hb_prioritize) + ) +} +HB_FUNCOBJ (hb_equal); + +struct +{ + template <typename T> void + operator () (T& a, T& b) const + { + using std::swap; // allow ADL + swap (a, b); + } +} +HB_FUNCOBJ (hb_swap); + + +template <typename T1, typename T2> +struct hb_pair_t +{ + typedef T1 first_t; + typedef T2 second_t; + typedef hb_pair_t<T1, T2> pair_t; + + template <typename U1 = T1, typename U2 = T2, + hb_enable_if (std::is_default_constructible<U1>::value && + std::is_default_constructible<U2>::value)> + hb_pair_t () : first (), second () {} + hb_pair_t (T1 a, T2 b) : first (std::forward<T1> (a)), second (std::forward<T2> (b)) {} + + template <typename Q1, typename Q2, + hb_enable_if (hb_is_convertible (T1, Q1) && + hb_is_convertible (T2, Q2))> + operator hb_pair_t<Q1, Q2> () { return hb_pair_t<Q1, Q2> (first, second); } + + hb_pair_t<T1, T2> reverse () const + { return hb_pair_t<T1, T2> (second, first); } + + bool operator == (const pair_t& o) const { return first == o.first && second == o.second; } + bool operator != (const pair_t& o) const { return !(*this == o); } + bool operator < (const pair_t& o) const { return first < o.first || (first == o.first && second < o.second); } + bool operator >= (const pair_t& o) const { return !(*this < o); } + bool operator > (const pair_t& o) const { return first > o.first || (first == o.first && second > o.second); } + bool operator <= (const pair_t& o) const { return !(*this > o); } + + static int cmp (const void *pa, const void *pb) + { + pair_t *a = (pair_t *) pa; + pair_t *b = (pair_t *) pb; + + if (a->first < b->first) return -1; + if (a->first > b->first) return +1; + if (a->second < b->second) return -1; + if (a->second > b->second) return +1; + return 0; + } + + friend void swap (hb_pair_t& a, hb_pair_t& b) + { + hb_swap (a.first, b.first); + hb_swap (a.second, b.second); + } + + + T1 first; + T2 second; +}; +template <typename T1, typename T2> static inline hb_pair_t<T1, T2> +hb_pair (T1&& a, T2&& b) { return hb_pair_t<T1, T2> (a, b); } + +typedef hb_pair_t<hb_codepoint_t, hb_codepoint_t> hb_codepoint_pair_t; + +struct +{ + template <typename Pair> constexpr typename Pair::first_t + operator () (const Pair& pair) const { return pair.first; } +} +HB_FUNCOBJ (hb_first); + +struct +{ + template <typename Pair> constexpr typename Pair::second_t + operator () (const Pair& pair) const { return pair.second; } +} +HB_FUNCOBJ (hb_second); + +/* Note. In min/max impl, we can use hb_type_identity<T> for second argument. + * However, that would silently convert between different-signedness integers. + * Instead we accept two different types, such that compiler can err if + * comparing integers of different signedness. */ +struct +{ + template <typename T, typename T2> constexpr auto + operator () (T&& a, T2&& b) const HB_AUTO_RETURN + (a <= b ? a : b) +} +HB_FUNCOBJ (hb_min); +struct +{ + template <typename T, typename T2> constexpr auto + operator () (T&& a, T2&& b) const HB_AUTO_RETURN + (a >= b ? a : b) +} +HB_FUNCOBJ (hb_max); +struct +{ + template <typename T, typename T2, typename T3> constexpr auto + operator () (T&& x, T2&& min, T3&& max) const HB_AUTO_RETURN + (hb_min (hb_max (std::forward<T> (x), std::forward<T2> (min)), std::forward<T3> (max))) +} +HB_FUNCOBJ (hb_clamp); + +/* + * Bithacks. + */ + +/* Return the number of 1 bits in v. */ +template <typename T> +static inline unsigned int +hb_popcount (T v) +{ +#if hb_has_builtin(__builtin_popcount) + if (sizeof (T) <= sizeof (unsigned int)) + return __builtin_popcount (v); +#endif + +#if hb_has_builtin(__builtin_popcountl) + if (sizeof (T) <= sizeof (unsigned long)) + return __builtin_popcountl (v); +#endif + +#if hb_has_builtin(__builtin_popcountll) + if (sizeof (T) <= sizeof (unsigned long long)) + return __builtin_popcountll (v); +#endif + + if (sizeof (T) <= 4) + { + /* "HACKMEM 169" */ + uint32_t y; + y = (v >> 1) &033333333333; + y = v - y - ((y >>1) & 033333333333); + return (((y + (y >> 3)) & 030707070707) % 077); + } + + if (sizeof (T) == 8) + { + uint64_t y = (uint64_t) v; + y -= ((y >> 1) & 0x5555555555555555ull); + y = (y & 0x3333333333333333ull) + (y >> 2 & 0x3333333333333333ull); + return ((y + (y >> 4)) & 0xf0f0f0f0f0f0f0full) * 0x101010101010101ull >> 56; + } + + if (sizeof (T) == 16) + { + unsigned int shift = 64; + return hb_popcount<uint64_t> ((uint64_t) v) + hb_popcount ((uint64_t) (v >> shift)); + } + + assert (0); + return 0; /* Shut up stupid compiler. */ +} + +/* Returns the number of bits needed to store number */ +template <typename T> +static inline unsigned int +hb_bit_storage (T v) +{ + if (unlikely (!v)) return 0; + +#if hb_has_builtin(__builtin_clz) + if (sizeof (T) <= sizeof (unsigned int)) + return sizeof (unsigned int) * 8 - __builtin_clz (v); +#endif + +#if hb_has_builtin(__builtin_clzl) + if (sizeof (T) <= sizeof (unsigned long)) + return sizeof (unsigned long) * 8 - __builtin_clzl (v); +#endif + +#if hb_has_builtin(__builtin_clzll) + if (sizeof (T) <= sizeof (unsigned long long)) + return sizeof (unsigned long long) * 8 - __builtin_clzll (v); +#endif + +#if (defined(_MSC_VER) && _MSC_VER >= 1500) || (defined(__MINGW32__) && (__GNUC__ < 4)) + if (sizeof (T) <= sizeof (unsigned int)) + { + unsigned long where; + _BitScanReverse (&where, v); + return 1 + where; + } +# if defined(_WIN64) + if (sizeof (T) <= 8) + { + unsigned long where; + _BitScanReverse64 (&where, v); + return 1 + where; + } +# endif +#endif + + if (sizeof (T) <= 4) + { + /* "bithacks" */ + const unsigned int b[] = {0x2, 0xC, 0xF0, 0xFF00, 0xFFFF0000}; + const unsigned int S[] = {1, 2, 4, 8, 16}; + unsigned int r = 0; + for (int i = 4; i >= 0; i--) + if (v & b[i]) + { + v >>= S[i]; + r |= S[i]; + } + return r + 1; + } + if (sizeof (T) <= 8) + { + /* "bithacks" */ + const uint64_t b[] = {0x2ULL, 0xCULL, 0xF0ULL, 0xFF00ULL, 0xFFFF0000ULL, 0xFFFFFFFF00000000ULL}; + const unsigned int S[] = {1, 2, 4, 8, 16, 32}; + unsigned int r = 0; + for (int i = 5; i >= 0; i--) + if (v & b[i]) + { + v >>= S[i]; + r |= S[i]; + } + return r + 1; + } + if (sizeof (T) == 16) + { + unsigned int shift = 64; + return (v >> shift) ? hb_bit_storage<uint64_t> ((uint64_t) (v >> shift)) + shift : + hb_bit_storage<uint64_t> ((uint64_t) v); + } + + assert (0); + return 0; /* Shut up stupid compiler. */ +} + +/* Returns the number of zero bits in the least significant side of v */ +template <typename T> +static inline unsigned int +hb_ctz (T v) +{ + if (unlikely (!v)) return 8 * sizeof (T); + +#if hb_has_builtin(__builtin_ctz) + if (sizeof (T) <= sizeof (unsigned int)) + return __builtin_ctz (v); +#endif + +#if hb_has_builtin(__builtin_ctzl) + if (sizeof (T) <= sizeof (unsigned long)) + return __builtin_ctzl (v); +#endif + +#if hb_has_builtin(__builtin_ctzll) + if (sizeof (T) <= sizeof (unsigned long long)) + return __builtin_ctzll (v); +#endif + +#if (defined(_MSC_VER) && _MSC_VER >= 1500) || (defined(__MINGW32__) && (__GNUC__ < 4)) + if (sizeof (T) <= sizeof (unsigned int)) + { + unsigned long where; + _BitScanForward (&where, v); + return where; + } +# if defined(_WIN64) + if (sizeof (T) <= 8) + { + unsigned long where; + _BitScanForward64 (&where, v); + return where; + } +# endif +#endif + + if (sizeof (T) <= 4) + { + /* "bithacks" */ + unsigned int c = 32; + v &= - (int32_t) v; + if (v) c--; + if (v & 0x0000FFFF) c -= 16; + if (v & 0x00FF00FF) c -= 8; + if (v & 0x0F0F0F0F) c -= 4; + if (v & 0x33333333) c -= 2; + if (v & 0x55555555) c -= 1; + return c; + } + if (sizeof (T) <= 8) + { + /* "bithacks" */ + unsigned int c = 64; + v &= - (int64_t) (v); + if (v) c--; + if (v & 0x00000000FFFFFFFFULL) c -= 32; + if (v & 0x0000FFFF0000FFFFULL) c -= 16; + if (v & 0x00FF00FF00FF00FFULL) c -= 8; + if (v & 0x0F0F0F0F0F0F0F0FULL) c -= 4; + if (v & 0x3333333333333333ULL) c -= 2; + if (v & 0x5555555555555555ULL) c -= 1; + return c; + } + if (sizeof (T) == 16) + { + unsigned int shift = 64; + return (uint64_t) v ? hb_bit_storage<uint64_t> ((uint64_t) v) : + hb_bit_storage<uint64_t> ((uint64_t) (v >> shift)) + shift; + } + + assert (0); + return 0; /* Shut up stupid compiler. */ +} + + +/* + * Tiny stuff. + */ + +/* ASCII tag/character handling */ +static inline bool ISALPHA (unsigned char c) +{ return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'); } +static inline bool ISALNUM (unsigned char c) +{ return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9'); } +static inline bool ISSPACE (unsigned char c) +{ return c == ' ' || c =='\f'|| c =='\n'|| c =='\r'|| c =='\t'|| c =='\v'; } +static inline unsigned char TOUPPER (unsigned char c) +{ return (c >= 'a' && c <= 'z') ? c - 'a' + 'A' : c; } +static inline unsigned char TOLOWER (unsigned char c) +{ return (c >= 'A' && c <= 'Z') ? c - 'A' + 'a' : c; } +static inline bool ISHEX (unsigned char c) +{ return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'); } +static inline unsigned char TOHEX (uint8_t c) +{ return (c & 0xF) <= 9 ? (c & 0xF) + '0' : (c & 0xF) + 'a' - 10; } +static inline uint8_t FROMHEX (unsigned char c) +{ return (c >= '0' && c <= '9') ? c - '0' : TOLOWER (c) - 'a' + 10; } + +static inline unsigned int DIV_CEIL (const unsigned int a, unsigned int b) +{ return (a + (b - 1)) / b; } + + +#undef ARRAY_LENGTH +template <typename Type, unsigned int n> +static inline unsigned int ARRAY_LENGTH (const Type (&)[n]) { return n; } +/* A const version, but does not detect erratically being called on pointers. */ +#define ARRAY_LENGTH_CONST(__array) ((signed int) (sizeof (__array) / sizeof (__array[0]))) + + +static inline void * +hb_memcpy (void *__restrict dst, const void *__restrict src, size_t len) +{ + /* It's illegal to pass 0 as size to memcpy. */ + if (unlikely (!len)) return dst; + return memcpy (dst, src, len); +} + +static inline int +hb_memcmp (const void *a, const void *b, unsigned int len) +{ + /* It's illegal to pass NULL to memcmp(), even if len is zero. + * So, wrap it. + * https://sourceware.org/bugzilla/show_bug.cgi?id=23878 */ + if (unlikely (!len)) return 0; + return memcmp (a, b, len); +} + +static inline void * +hb_memset (void *s, int c, unsigned int n) +{ + /* It's illegal to pass NULL to memset(), even if n is zero. */ + if (unlikely (!n)) return s; + return memset (s, c, n); +} + +static inline unsigned int +hb_ceil_to_4 (unsigned int v) +{ + return ((v - 1) | 3) + 1; +} + +template <typename T> static inline bool +hb_in_range (T u, T lo, T hi) +{ + static_assert (!std::is_signed<T>::value, ""); + + /* The casts below are important as if T is smaller than int, + * the subtract results will become a signed int! */ + return (T)(u - lo) <= (T)(hi - lo); +} +template <typename T> static inline bool +hb_in_ranges (T u, T lo1, T hi1) +{ + return hb_in_range (u, lo1, hi1); +} +template <typename T, typename ...Ts> static inline bool +hb_in_ranges (T u, T lo1, T hi1, Ts... ds) +{ + return hb_in_range<T> (u, lo1, hi1) || hb_in_ranges<T> (u, ds...); +} + + +/* + * Overflow checking. + */ + +static inline bool +hb_unsigned_mul_overflows (unsigned int count, unsigned int size, unsigned *result = nullptr) +{ +#if hb_has_builtin(__builtin_mul_overflow) + unsigned stack_result; + if (!result) + result = &stack_result; + return __builtin_mul_overflow (count, size, result); +#endif + + if (result) + *result = count * size; + return (size > 0) && (count >= ((unsigned int) -1) / size); +} + + +/* + * Sort and search. + */ + +template <typename K, typename V, typename ...Ts> +static int +_hb_cmp_method (const void *pkey, const void *pval, Ts... ds) +{ + const K& key = * (const K*) pkey; + const V& val = * (const V*) pval; + + return val.cmp (key, ds...); +} + +template <typename V, typename K, typename ...Ts> +static inline bool +hb_bsearch_impl (unsigned *pos, /* Out */ + const K& key, + V* base, size_t nmemb, size_t stride, + int (*compar)(const void *_key, const void *_item, Ts... _ds), + Ts... ds) +{ + /* This is our *only* bsearch implementation. */ + + int min = 0, max = (int) nmemb - 1; + while (min <= max) + { + int mid = ((unsigned int) min + (unsigned int) max) / 2; +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wcast-align" + V* p = (V*) (((const char *) base) + (mid * stride)); +#pragma GCC diagnostic pop + int c = compar ((const void *) std::addressof (key), (const void *) p, ds...); + if (c < 0) + max = mid - 1; + else if (c > 0) + min = mid + 1; + else + { + *pos = mid; + return true; + } + } + *pos = min; + return false; +} + +template <typename V, typename K> +static inline V* +hb_bsearch (const K& key, V* base, + size_t nmemb, size_t stride = sizeof (V), + int (*compar)(const void *_key, const void *_item) = _hb_cmp_method<K, V>) +{ + unsigned pos; +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wcast-align" + return hb_bsearch_impl (&pos, key, base, nmemb, stride, compar) ? + (V*) (((const char *) base) + (pos * stride)) : nullptr; +#pragma GCC diagnostic pop +} +template <typename V, typename K, typename ...Ts> +static inline V* +hb_bsearch (const K& key, V* base, + size_t nmemb, size_t stride, + int (*compar)(const void *_key, const void *_item, Ts... _ds), + Ts... ds) +{ + unsigned pos; +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wcast-align" + return hb_bsearch_impl (&pos, key, base, nmemb, stride, compar, ds...) ? + (V*) (((const char *) base) + (pos * stride)) : nullptr; +#pragma GCC diagnostic pop +} + + +/* From https://github.com/noporpoise/sort_r + Feb 5, 2019 (c8c65c1e) + Modified to support optional argument using templates */ + +/* Isaac Turner 29 April 2014 Public Domain */ + +/* +hb_qsort function to be exported. +Parameters: + base is the array to be sorted + nel is the number of elements in the array + width is the size in bytes of each element of the array + compar is the comparison function + arg (optional) is a pointer to be passed to the comparison function + +void hb_qsort(void *base, size_t nel, size_t width, + int (*compar)(const void *_a, const void *_b, [void *_arg]), + [void *arg]); +*/ + +#define SORT_R_SWAP(a,b,tmp) ((void) ((tmp) = (a)), (void) ((a) = (b)), (b) = (tmp)) + +/* swap a and b */ +/* a and b must not be equal! */ +static inline void sort_r_swap(char *__restrict a, char *__restrict b, + size_t w) +{ + char tmp, *end = a+w; + for(; a < end; a++, b++) { SORT_R_SWAP(*a, *b, tmp); } +} + +/* swap a, b iff a>b */ +/* a and b must not be equal! */ +/* __restrict is same as restrict but better support on old machines */ +template <typename ...Ts> +static inline int sort_r_cmpswap(char *__restrict a, + char *__restrict b, size_t w, + int (*compar)(const void *_a, + const void *_b, + Ts... _ds), + Ts... ds) +{ + if(compar(a, b, ds...) > 0) { + sort_r_swap(a, b, w); + return 1; + } + return 0; +} + +/* +Swap consecutive blocks of bytes of size na and nb starting at memory addr ptr, +with the smallest swap so that the blocks are in the opposite order. Blocks may +be internally re-ordered e.g. + 12345ab -> ab34512 + 123abc -> abc123 + 12abcde -> deabc12 +*/ +static inline void sort_r_swap_blocks(char *ptr, size_t na, size_t nb) +{ + if(na > 0 && nb > 0) { + if(na > nb) { sort_r_swap(ptr, ptr+na, nb); } + else { sort_r_swap(ptr, ptr+nb, na); } + } +} + +/* Implement recursive quicksort ourselves */ +/* Note: quicksort is not stable, equivalent values may be swapped */ +template <typename ...Ts> +static inline void sort_r_simple(void *base, size_t nel, size_t w, + int (*compar)(const void *_a, + const void *_b, + Ts... _ds), + Ts... ds) +{ + char *b = (char *)base, *end = b + nel*w; + + /* for(size_t i=0; i<nel; i++) {printf("%4i", *(int*)(b + i*sizeof(int)));} + printf("\n"); */ + + if(nel < 10) { + /* Insertion sort for arbitrarily small inputs */ + char *pi, *pj; + for(pi = b+w; pi < end; pi += w) { + for(pj = pi; pj > b && sort_r_cmpswap(pj-w,pj,w,compar,ds...); pj -= w) {} + } + } + else + { + /* nel > 9; Quicksort */ + + int cmp; + char *pl, *ple, *pr, *pre, *pivot; + char *last = b+w*(nel-1), *tmp; + + /* + Use median of second, middle and second-last items as pivot. + First and last may have been swapped with pivot and therefore be extreme + */ + char *l[3]; + l[0] = b + w; + l[1] = b+w*(nel/2); + l[2] = last - w; + + /* printf("pivots: %i, %i, %i\n", *(int*)l[0], *(int*)l[1], *(int*)l[2]); */ + + if(compar(l[0],l[1],ds...) > 0) { SORT_R_SWAP(l[0], l[1], tmp); } + if(compar(l[1],l[2],ds...) > 0) { + SORT_R_SWAP(l[1], l[2], tmp); + if(compar(l[0],l[1],ds...) > 0) { SORT_R_SWAP(l[0], l[1], tmp); } + } + + /* swap mid value (l[1]), and last element to put pivot as last element */ + if(l[1] != last) { sort_r_swap(l[1], last, w); } + + /* + pl is the next item on the left to be compared to the pivot + pr is the last item on the right that was compared to the pivot + ple is the left position to put the next item that equals the pivot + ple is the last right position where we put an item that equals the pivot + v- end (beyond the array) + EEEEEELLLLLLLLuuuuuuuuGGGGGGGEEEEEEEE. + ^- b ^- ple ^- pl ^- pr ^- pre ^- last (where the pivot is) + Pivot comparison key: + E = equal, L = less than, u = unknown, G = greater than, E = equal + */ + pivot = last; + ple = pl = b; + pre = pr = last; + + /* + Strategy: + Loop into the list from the left and right at the same time to find: + - an item on the left that is greater than the pivot + - an item on the right that is less than the pivot + Once found, they are swapped and the loop continues. + Meanwhile items that are equal to the pivot are moved to the edges of the + array. + */ + while(pl < pr) { + /* Move left hand items which are equal to the pivot to the far left. + break when we find an item that is greater than the pivot */ + for(; pl < pr; pl += w) { + cmp = compar(pl, pivot, ds...); + if(cmp > 0) { break; } + else if(cmp == 0) { + if(ple < pl) { sort_r_swap(ple, pl, w); } + ple += w; + } + } + /* break if last batch of left hand items were equal to pivot */ + if(pl >= pr) { break; } + /* Move right hand items which are equal to the pivot to the far right. + break when we find an item that is less than the pivot */ + for(; pl < pr; ) { + pr -= w; /* Move right pointer onto an unprocessed item */ + cmp = compar(pr, pivot, ds...); + if(cmp == 0) { + pre -= w; + if(pr < pre) { sort_r_swap(pr, pre, w); } + } + else if(cmp < 0) { + if(pl < pr) { sort_r_swap(pl, pr, w); } + pl += w; + break; + } + } + } + + pl = pr; /* pr may have gone below pl */ + + /* + Now we need to go from: EEELLLGGGGEEEE + to: LLLEEEEEEEGGGG + Pivot comparison key: + E = equal, L = less than, u = unknown, G = greater than, E = equal + */ + sort_r_swap_blocks(b, ple-b, pl-ple); + sort_r_swap_blocks(pr, pre-pr, end-pre); + + /*for(size_t i=0; i<nel; i++) {printf("%4i", *(int*)(b + i*sizeof(int)));} + printf("\n");*/ + + sort_r_simple(b, (pl-ple)/w, w, compar, ds...); + sort_r_simple(end-(pre-pr), (pre-pr)/w, w, compar, ds...); + } +} + +static inline void +hb_qsort (void *base, size_t nel, size_t width, + int (*compar)(const void *_a, const void *_b)) +{ +#if defined(__OPTIMIZE_SIZE__) && !defined(HB_USE_INTERNAL_QSORT) + qsort (base, nel, width, compar); +#else + sort_r_simple (base, nel, width, compar); +#endif +} + +static inline void +hb_qsort (void *base, size_t nel, size_t width, + int (*compar)(const void *_a, const void *_b, void *_arg), + void *arg) +{ +#ifdef HAVE_GNU_QSORT_R + qsort_r (base, nel, width, compar, arg); +#else + sort_r_simple (base, nel, width, compar, arg); +#endif +} + + +template <typename T, typename T2, typename T3 = int> static inline void +hb_stable_sort (T *array, unsigned int len, int(*compar)(const T2 *, const T2 *), T3 *array2 = nullptr) +{ + static_assert (hb_is_trivially_copy_assignable (T), ""); + static_assert (hb_is_trivially_copy_assignable (T3), ""); + + for (unsigned int i = 1; i < len; i++) + { + unsigned int j = i; + while (j && compar (&array[j - 1], &array[i]) > 0) + j--; + if (i == j) + continue; + /* Move item i to occupy place for item j, shift what's in between. */ + { + T t = array[i]; + memmove (&array[j + 1], &array[j], (i - j) * sizeof (T)); + array[j] = t; + } + if (array2) + { + T3 t = array2[i]; + memmove (&array2[j + 1], &array2[j], (i - j) * sizeof (T3)); + array2[j] = t; + } + } +} + +static inline hb_bool_t +hb_codepoint_parse (const char *s, unsigned int len, int base, hb_codepoint_t *out) +{ + unsigned int v; + const char *p = s; + const char *end = p + len; + if (unlikely (!hb_parse_uint (&p, end, &v, true/* whole buffer */, base))) + return false; + + *out = v; + return true; +} + + +/* Operators. */ + +struct +{ HB_PARTIALIZE(2); + template <typename T> constexpr auto + operator () (const T &a, const T &b) const HB_AUTO_RETURN (a & b) +} +HB_FUNCOBJ (hb_bitwise_and); +struct +{ HB_PARTIALIZE(2); + template <typename T> constexpr auto + operator () (const T &a, const T &b) const HB_AUTO_RETURN (a | b) +} +HB_FUNCOBJ (hb_bitwise_or); +struct +{ HB_PARTIALIZE(2); + template <typename T> constexpr auto + operator () (const T &a, const T &b) const HB_AUTO_RETURN (a ^ b) +} +HB_FUNCOBJ (hb_bitwise_xor); +struct +{ HB_PARTIALIZE(2); + template <typename T> constexpr auto + operator () (const T &a, const T &b) const HB_AUTO_RETURN (~a & b) +} +HB_FUNCOBJ (hb_bitwise_lt); +struct +{ HB_PARTIALIZE(2); + template <typename T> constexpr auto + operator () (const T &a, const T &b) const HB_AUTO_RETURN (a & ~b) +} +HB_FUNCOBJ (hb_bitwise_gt); // aka sub +struct +{ HB_PARTIALIZE(2); + template <typename T> constexpr auto + operator () (const T &a, const T &b) const HB_AUTO_RETURN (~a | b) +} +HB_FUNCOBJ (hb_bitwise_le); +struct +{ HB_PARTIALIZE(2); + template <typename T> constexpr auto + operator () (const T &a, const T &b) const HB_AUTO_RETURN (a | ~b) +} +HB_FUNCOBJ (hb_bitwise_ge); +struct +{ + template <typename T> constexpr auto + operator () (const T &a) const HB_AUTO_RETURN (~a) +} +HB_FUNCOBJ (hb_bitwise_neg); + +struct +{ HB_PARTIALIZE(2); + template <typename T, typename T2> constexpr auto + operator () (const T &a, const T2 &b) const HB_AUTO_RETURN (a + b) +} +HB_FUNCOBJ (hb_add); +struct +{ HB_PARTIALIZE(2); + template <typename T, typename T2> constexpr auto + operator () (const T &a, const T2 &b) const HB_AUTO_RETURN (a - b) +} +HB_FUNCOBJ (hb_sub); +struct +{ HB_PARTIALIZE(2); + template <typename T, typename T2> constexpr auto + operator () (const T &a, const T2 &b) const HB_AUTO_RETURN (b - a) +} +HB_FUNCOBJ (hb_rsub); +struct +{ HB_PARTIALIZE(2); + template <typename T, typename T2> constexpr auto + operator () (const T &a, const T2 &b) const HB_AUTO_RETURN (a * b) +} +HB_FUNCOBJ (hb_mul); +struct +{ HB_PARTIALIZE(2); + template <typename T, typename T2> constexpr auto + operator () (const T &a, const T2 &b) const HB_AUTO_RETURN (a / b) +} +HB_FUNCOBJ (hb_div); +struct +{ HB_PARTIALIZE(2); + template <typename T, typename T2> constexpr auto + operator () (const T &a, const T2 &b) const HB_AUTO_RETURN (a % b) +} +HB_FUNCOBJ (hb_mod); +struct +{ + template <typename T> constexpr auto + operator () (const T &a) const HB_AUTO_RETURN (+a) +} +HB_FUNCOBJ (hb_pos); +struct +{ + template <typename T> constexpr auto + operator () (const T &a) const HB_AUTO_RETURN (-a) +} +HB_FUNCOBJ (hb_neg); +struct +{ + template <typename T> constexpr auto + operator () (T &a) const HB_AUTO_RETURN (++a) +} +HB_FUNCOBJ (hb_inc); +struct +{ + template <typename T> constexpr auto + operator () (T &a) const HB_AUTO_RETURN (--a) +} +HB_FUNCOBJ (hb_dec); + + +/* Adapted from kurbo implementation with extra parameters added, + * and finding for a particular range instead of 0. + * + * For documentation and implementation see: + * + * [ITP method]: https://en.wikipedia.org/wiki/ITP_Method + * [An Enhancement of the Bisection Method Average Performance Preserving Minmax Optimality]: https://dl.acm.org/doi/10.1145/3423597 + * https://docs.rs/kurbo/0.8.1/kurbo/common/fn.solve_itp.html + * https://github.com/linebender/kurbo/blob/fd839c25ea0c98576c7ce5789305822675a89938/src/common.rs#L162-L248 + */ +template <typename func_t> +double solve_itp (func_t f, + double a, double b, + double epsilon, + double min_y, double max_y, + double &ya, double &yb, double &y) +{ + unsigned n1_2 = (unsigned) (hb_max (ceil (log2 ((b - a) / epsilon)) - 1.0, 0.0)); + const unsigned n0 = 1; // Hardwired + const double k1 = 0.2 / (b - a); // Hardwired. + unsigned nmax = n0 + n1_2; + double scaled_epsilon = epsilon * double (1llu << nmax); + double _2_epsilon = 2.0 * epsilon; + while (b - a > _2_epsilon) + { + double x1_2 = 0.5 * (a + b); + double r = scaled_epsilon - 0.5 * (b - a); + double xf = (yb * a - ya * b) / (yb - ya); + double sigma = x1_2 - xf; + double b_a = b - a; + // This has k2 = 2 hardwired for efficiency. + double b_a_k2 = b_a * b_a; + double delta = k1 * b_a_k2; + int sigma_sign = sigma >= 0 ? +1 : -1; + double xt = delta <= fabs (x1_2 - xf) ? xf + delta * sigma_sign : x1_2; + double xitp = fabs (xt - x1_2) <= r ? xt : x1_2 - r * sigma_sign; + double yitp = f (xitp); + if (yitp > max_y) + { + b = xitp; + yb = yitp; + } + else if (yitp < min_y) + { + a = xitp; + ya = yitp; + } + else + { + y = yitp; + return xitp; + } + scaled_epsilon *= 0.5; + } + return 0.5 * (a + b); +} + + +#endif /* HB_ALGS_HH */ |