source/texk/web2c/luatexdir/luafontloader/fontforge/fontforge/splinerefigure.c

   1 /* Copyright (C) 2000-2008 by George Williams */
   2 /*
   3  * Redistribution and use in source and binary forms, with or without
   4  * modification, are permitted provided that the following conditions are met:
   5
   6  * Redistributions of source code must retain the above copyright notice, this
   7  * list of conditions and the following disclaimer.
   8
   9  * Redistributions in binary form must reproduce the above copyright notice,
  10  * this list of conditions and the following disclaimer in the documentation
  11  * and/or other materials provided with the distribution.
  12
  13  * The name of the author may not be used to endorse or promote products
  14  * derived from this software without specific prior written permission.
  15
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
  19  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  20  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27 #include "pfaedit.h"
  28 #include <stdio.h>
  29 #include <math.h>
  30 #include "splinefont.h"
  31 #ifdef HAVE_IEEEFP_H
  32 # include <ieeefp.h>            /* Solaris defines isnan in ieeefp rather than math.h */
  33 #endif
  34
  35 /* The slight errors introduced by the optimizer turn out to have nasty */
  36 /*  side effects. An error on the order of 7e-8 in splines[1].b caused */
  37 /*  the rasterizer to have kaniptions */
  38 void SplineRefigure3(Spline *spline) {
  39     SplinePoint *from = spline->from, *to = spline->to;
  40     Spline1D *xsp = &spline->splines[0], *ysp = &spline->splines[1];
  41     Spline old;
  42
  43 #ifdef DEBUG
  44     if ( RealNear(from->me.x,to->me.x) && RealNear(from->me.y,to->me.y))
  45         IError("Zero length spline created");
  46 #endif
  47     if ( spline->acceptableextrema )
  48         old = *spline;
  49     xsp->d = from->me.x; ysp->d = from->me.y;
  50     if ( from->nonextcp ) from->nextcp = from->me;
  51     else if ( from->nextcp.x==from->me.x && from->nextcp.y == from->me.y ) from->nonextcp = true;
  52     if ( to->noprevcp ) to->prevcp = to->me;
  53     else if ( to->prevcp.x==to->me.x && to->prevcp.y == to->me.y ) to->noprevcp = true;
  54     if ( from->nonextcp && to->noprevcp ) {
  55         spline->islinear = true;
  56         xsp->c = to->me.x-from->me.x;
  57         ysp->c = to->me.y-from->me.y;
  58         xsp->a = xsp->b = 0;
  59         ysp->a = ysp->b = 0;
  60     } else {
  61         /* from p. 393 (Operator Details, curveto) Postscript Lang. Ref. Man. (Red book) */
  62         xsp->c = 3*(from->nextcp.x-from->me.x);
  63         ysp->c = 3*(from->nextcp.y-from->me.y);
  64         xsp->b = 3*(to->prevcp.x-from->nextcp.x)-xsp->c;
  65         ysp->b = 3*(to->prevcp.y-from->nextcp.y)-ysp->c;
  66         xsp->a = to->me.x-from->me.x-xsp->c-xsp->b;
  67         ysp->a = to->me.y-from->me.y-ysp->c-ysp->b;
  68         if ( RealNear(xsp->c,0)) xsp->c=0;
  69         if ( RealNear(ysp->c,0)) ysp->c=0;
  70         if ( RealNear(xsp->b,0)) xsp->b=0;
  71         if ( RealNear(ysp->b,0)) ysp->b=0;
  72         if ( RealNear(xsp->a,0)) xsp->a=0;
  73         if ( RealNear(ysp->a,0)) ysp->a=0;
  74         spline->islinear = false;
  75         if ( ysp->a==0 && xsp->a==0 && ysp->b==0 && xsp->b==0 )
  76             spline->islinear = true;    /* This seems extremely unlikely... */
  77     }
  78     if ( !finite(ysp->a) || !finite(xsp->a) || !finite(ysp->c) || !finite(xsp->c) || !finite(ysp->d) || !finite(xsp->d))
  79         IError("NaN value in spline creation");
  80     LinearApproxFree(spline->approx);
  81     spline->approx = NULL;
  82     spline->knowncurved = false;
  83     spline->knownlinear = spline->islinear;
  84     SplineIsLinear(spline);
  85     spline->isquadratic = false;
  86     if ( !spline->knownlinear && xsp->a==0 && ysp->a==0 )
  87         spline->isquadratic = true;     /* Only likely if we read in a TTF */
  88     spline->order2 = false;
  89
  90     if ( spline->acceptableextrema ) {
  91         /* I don't check "d", because changes to that reflect simple */
  92         /*  translations which will not affect the shape of the spline */
  93         if ( !RealNear(old.splines[0].a,spline->splines[0].a) ||
  94                 !RealNear(old.splines[0].b,spline->splines[0].b) ||
  95                 !RealNear(old.splines[0].c,spline->splines[0].c) ||
  96                 !RealNear(old.splines[1].a,spline->splines[1].a) ||
  97                 !RealNear(old.splines[1].b,spline->splines[1].b) ||
  98                 !RealNear(old.splines[1].c,spline->splines[1].c) )
  99             spline->acceptableextrema = false;
 100     }
 101 }