virtualx-engine/thirdparty/harfbuzz/src/hb-subset-instancer-solver.hh
2023-09-05 08:27:29 +03:00

112 lines
3.6 KiB
C++

/*
* 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.
*/
#ifndef HB_SUBSET_INSTANCER_SOLVER_HH
#define HB_SUBSET_INSTANCER_SOLVER_HH
#include "hb.hh"
/* pre-normalized distances */
struct TripleDistances
{
TripleDistances (): negative (1.f), positive (1.f) {}
TripleDistances (float neg_, float pos_): negative (neg_), positive (pos_) {}
TripleDistances (float min, float default_, float max)
{
negative = default_ - min;
positive = max - default_;
}
float negative;
float positive;
};
struct Triple {
Triple () :
minimum (0.f), middle (0.f), maximum (0.f) {}
Triple (float minimum_, float middle_, float maximum_) :
minimum (minimum_), middle (middle_), maximum (maximum_) {}
bool operator == (const Triple &o) const
{
return minimum == o.minimum &&
middle == o.middle &&
maximum == o.maximum;
}
bool operator != (const Triple o) const
{ return !(*this == o); }
bool is_point () const
{ return minimum == middle && middle == maximum; }
bool contains (float point) const
{ return minimum <= point && point <= maximum; }
/* from hb_array_t hash ()*/
uint32_t hash () const
{
uint32_t current = /*cbf29ce4*/0x84222325;
current = current ^ hb_hash (minimum);
current = current * 16777619;
current = current ^ hb_hash (middle);
current = current * 16777619;
current = current ^ hb_hash (maximum);
current = current * 16777619;
return current;
}
float minimum;
float middle;
float maximum;
};
using result_item_t = hb_pair_t<float, Triple>;
using result_t = hb_vector_t<result_item_t>;
/* renormalize a normalized value v to the range of an axis,
* considering the prenormalized distances as well as the new axis limits.
* Ported from fonttools */
HB_INTERNAL float renormalizeValue (float v, const Triple &triple,
const TripleDistances &triple_distances,
bool extrapolate = true);
/* Given a tuple (lower,peak,upper) "tent" and new axis limits
* (axisMin,axisDefault,axisMax), solves how to represent the tent
* under the new axis configuration. All values are in normalized
* -1,0,+1 coordinate system. Tent values can be outside this range.
*
* Return value: a list of tuples. Each tuple is of the form
* (scalar,tent), where scalar is a multipler to multiply any
* delta-sets by, and tent is a new tent for that output delta-set.
* If tent value is Triple{}, that is a special deltaset that should
* be always-enabled (called "gain").
*/
HB_INTERNAL result_t rebase_tent (Triple tent, Triple axisLimit, TripleDistances axis_triple_distances);
#endif /* HB_SUBSET_INSTANCER_SOLVER_HH */