hb-subset-instancer-solver.hh (3827B)
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 { 33 TripleDistances (): negative (1.0), positive (1.0) {} 34 TripleDistances (double neg_, double pos_): negative (neg_), positive (pos_) {} 35 TripleDistances (double min, double default_, double max) 36 { 37 negative = default_ - min; 38 positive = max - default_; 39 } 40 41 double negative; 42 double positive; 43 }; 44 45 struct Triple 46 { 47 Triple () = default; 48 49 Triple (double minimum_, double middle_, double maximum_) : 50 minimum (minimum_), middle (middle_), maximum (maximum_) {} 51 52 bool operator == (const Triple &o) const 53 { 54 return minimum == o.minimum && 55 middle == o.middle && 56 maximum == o.maximum; 57 } 58 59 bool operator != (const Triple o) const 60 { return !(*this == o); } 61 62 bool is_point () const 63 { return minimum == middle && middle == maximum; } 64 65 bool contains (double point) const 66 { return minimum <= point && point <= maximum; } 67 68 /* from hb_array_t hash ()*/ 69 uint32_t hash () const 70 { 71 uint32_t current = /*cbf29ce4*/0x84222325; 72 current = current ^ hb_hash (minimum); 73 current = current * 16777619; 74 75 current = current ^ hb_hash (middle); 76 current = current * 16777619; 77 78 current = current ^ hb_hash (maximum); 79 current = current * 16777619; 80 return current; 81 } 82 83 double minimum = 0; 84 double middle = 0; 85 double maximum = 0; 86 }; 87 88 using rebase_tent_result_item_t = hb_pair_t<double, Triple>; 89 using rebase_tent_result_t = hb_vector_t<rebase_tent_result_item_t>; 90 91 /* renormalize a normalized value v to the range of an axis, 92 * considering the prenormalized distances as well as the new axis limits. 93 * Ported from fonttools */ 94 HB_INTERNAL double renormalizeValue (double v, const Triple &triple, 95 const TripleDistances &triple_distances, 96 bool extrapolate = true); 97 /* Given a tuple (lower,peak,upper) "tent" and new axis limits 98 * (axisMin,axisDefault,axisMax), solves how to represent the tent 99 * under the new axis configuration. All values are in normalized 100 * -1,0,+1 coordinate system. Tent values can be outside this range. 101 * 102 * Return value: a list of tuples. Each tuple is of the form 103 * (scalar,tent), where scalar is a multipler to multiply any 104 * delta-sets by, and tent is a new tent for that output delta-set. 105 * If tent value is Triple{}, that is a special deltaset that should 106 * be always-enabled (called "gain"). 107 */ 108 HB_INTERNAL void rebase_tent (Triple tent, 109 Triple axisLimit, 110 TripleDistances axis_triple_distances, 111 rebase_tent_result_t &out, 112 rebase_tent_result_t &scratch); 113 114 #endif /* HB_SUBSET_INSTANCER_SOLVER_HH */