1 /* 2 * Copyright © 2023 Behdad Esfahbod 3 * 4 * This is part of HarfBuzz, a text shaping library. 5 * 6 * Permission is hereby granted, without written agreement and without 7 * license or royalty fees, to use, copy, modify, and distribute this 8 * software and its documentation for any purpose, provided that the 9 * above copyright notice and the following two paragraphs appear in 10 * all copies of this software. 11 * 12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR 13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES 14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN 15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 16 * DAMAGE. 17 * 18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, 19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS 21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO 22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. 23 */ 24 25 #ifndef HB_SUBSET_INSTANCER_SOLVER_HH 26 #define HB_SUBSET_INSTANCER_SOLVER_HH 27 28 #include "hb.hh" 29 30 /* pre-normalized distances */ 31 struct TripleDistances 32 { TripleDistancesTripleDistances33 TripleDistances (): negative (1.f), positive (1.f) {} TripleDistancesTripleDistances34 TripleDistances (float neg_, float pos_): negative (neg_), positive (pos_) {} TripleDistancesTripleDistances35 TripleDistances (float min, float default_, float max) 36 { 37 negative = default_ - min; 38 positive = max - default_; 39 } 40 41 float negative; 42 float positive; 43 }; 44 45 struct Triple { 46 TripleTriple47 Triple () : 48 minimum (0.f), middle (0.f), maximum (0.f) {} 49 TripleTriple50 Triple (float minimum_, float middle_, float maximum_) : 51 minimum (minimum_), middle (middle_), maximum (maximum_) {} 52 operator ==Triple53 bool operator == (const Triple &o) const 54 { 55 return minimum == o.minimum && 56 middle == o.middle && 57 maximum == o.maximum; 58 } 59 operator !=Triple60 bool operator != (const Triple o) const 61 { return !(*this == o); } 62 is_pointTriple63 bool is_point () const 64 { return minimum == middle && middle == maximum; } 65 containsTriple66 bool contains (float point) const 67 { return minimum <= point && point <= maximum; } 68 69 /* from hb_array_t hash ()*/ hashTriple70 uint32_t hash () const 71 { 72 uint32_t current = /*cbf29ce4*/0x84222325; 73 current = current ^ hb_hash (minimum); 74 current = current * 16777619; 75 76 current = current ^ hb_hash (middle); 77 current = current * 16777619; 78 79 current = current ^ hb_hash (maximum); 80 current = current * 16777619; 81 return current; 82 } 83 84 85 float minimum; 86 float middle; 87 float maximum; 88 }; 89 90 using result_item_t = hb_pair_t<float, Triple>; 91 using result_t = hb_vector_t<result_item_t>; 92 93 /* renormalize a normalized value v to the range of an axis, 94 * considering the prenormalized distances as well as the new axis limits. 95 * Ported from fonttools */ 96 HB_INTERNAL float renormalizeValue (float v, const Triple &triple, 97 const TripleDistances &triple_distances, 98 bool extrapolate = true); 99 /* Given a tuple (lower,peak,upper) "tent" and new axis limits 100 * (axisMin,axisDefault,axisMax), solves how to represent the tent 101 * under the new axis configuration. All values are in normalized 102 * -1,0,+1 coordinate system. Tent values can be outside this range. 103 * 104 * Return value: a list of tuples. Each tuple is of the form 105 * (scalar,tent), where scalar is a multipler to multiply any 106 * delta-sets by, and tent is a new tent for that output delta-set. 107 * If tent value is Triple{}, that is a special deltaset that should 108 * be always-enabled (called "gain"). 109 */ 110 HB_INTERNAL result_t rebase_tent (Triple tent, Triple axisLimit, TripleDistances axis_triple_distances); 111 112 #endif /* HB_SUBSET_INSTANCER_SOLVER_HH */ 113