chromium/third_party/harfbuzz-ng/src/src/hb-subset-instancer-solver.cc

/*
 * Copyright © 2023  Behdad Esfahbod
 *
 *  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.
 */

#include "hb-subset-instancer-solver.hh"

/* This file is a straight port of the following:
 *
 * https://github.com/fonttools/fonttools/blob/f73220816264fc383b8a75f2146e8d69e455d398/Lib/fontTools/varLib/instancer/solver.py
 *
 * Where that file returns None for a triple, we return Triple{}.
 * This should be safe.
 */

constexpr static double EPSILON = …;
constexpr static double MAX_F2DOT14 = …;

static inline Triple _reverse_negate(const Triple &v)
{ … }


static inline double supportScalar (double coord, const Triple &tent)
{ … }

static inline rebase_tent_result_t
_solve (Triple tent, Triple axisLimit, bool negative = false)
{ … }

static inline TripleDistances _reverse_triple_distances (const TripleDistances &v)
{ … }

double renormalizeValue (double v, const Triple &triple,
                         const TripleDistances &triple_distances, bool extrapolate)
{ … }

rebase_tent_result_t
rebase_tent (Triple tent, Triple axisLimit, TripleDistances axis_triple_distances)
{ … }