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Diffstat (limited to 'src/path/splinefit/splinefit.h')
| -rw-r--r-- | src/path/splinefit/splinefit.h | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/src/path/splinefit/splinefit.h b/src/path/splinefit/splinefit.h new file mode 100644 index 0000000..22e21fc --- /dev/null +++ b/src/path/splinefit/splinefit.h @@ -0,0 +1,78 @@ +// 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 */ |