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// SPDX-License-Identifier: GPL-2.0-or-later
/* Copyright (C) 2000-2012 by George Williams, 2019 by Skef Iterum, 2021 by Linus Romer */
/*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef FONTFORGE_SPLINEFIT_H
#define FONTFORGE_SPLINEFIT_H
// #include <fontforge-config.h>
#include "splinefont.h"
typedef struct fitpoint {
BasePoint p;
BasePoint ut;
bigreal t;
} FitPoint;
#define FITPOINT_EMPTY { {0.0, 0.0}, {0.0, 0.0}, 0.0 }
enum mergetype { mt_matrix, mt_levien, mt_bruteforce };
extern Spline *ApproximateSplineFromPoints(SplinePoint *from, SplinePoint *to,
FitPoint *mid, int cnt, int order2);
extern Spline *ApproximateSplineFromPointsSlopes(SplinePoint *from, SplinePoint *to,
FitPoint *mid, int cnt, int order2, enum mergetype mt);
/* ApproximateSplineSetFromGen() fits a one or more splines to data
* generated by calls to genp, within the tolerance toler. The data
* are treated as noiseless although some noise may be harmless. When
* an interval cannot be fit with a single spline it is divided at
* the point of largest error, where the position and slope are fixed
* according to the FitPoint entries.
*
* A GenPointsP function should allocate a free-able array of FitPoints,
* set *fpp to point to it, and return the number of points allocated.
* The points should correspond to values chosen between the interval
* t_start and t_end, but just what this interval corresponds to depends
* on vinfo and is therefore opaque to the tracing system. It is up to the
* implementation how many points to return on the interval and how they are
* "t-spaced".
*
* The function can also return 0 points, in which case *fpp should be set
* to NULL. This will cancel the tracing. This semantic is useful for
* communicating information found during tracing back to the caller
* of ApproximateSplineSetFromGen(), presumably via the vinfo structure,
* so that it can retrace with a different choice of interval.
*/
typedef int (*GenPointsP)(void *vinfo, bigreal t_start, bigreal t_end, FitPoint **fpp);
extern SplinePoint *ApproximateSplineSetFromGen(SplinePoint *from, SplinePoint *to,
bigreal start_t, bigreal end_t,
bigreal toler, int toler_is_sumsq,
GenPointsP genp, void *tok, int order2);
#endif /* FONTFORGE_SPLINEFIT_H */
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