/* * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ /*Produce spline (uniform knots, second order)from guiding points*/#include "mplot.h"void splin(int mode, int num[], double *ff[]){ int i, *np, n; double xa, ya, xc, yc, *xp, *yp, *xp0, *yp0, *xpe, *ype; double **fp; np = num; fp = ff; while((n = *np++)){ xp = *fp++; yp = xp + 1; xp0 = xp; yp0 = yp; xpe = xp0 + 2 * (n - 1); ype = yp0 + 2 * (n - 1); if (n < 3) { plotline(*xp, *yp, *(xp + 2), *(yp + 2)); continue; } if (mode == 4) { /*closed curve*/ xa = 0.5 * (*xpe + *(xpe - 2)); xc = 0.5 * (*xpe + *xp0); ya = 0.5 * (*ype + *(ype - 2)); yc = 0.5 * (*ype + *yp0); parabola(xa, ya, xc, yc, *xpe, *ype); xa = 0.5 * (*xpe + *xp0); xc = 0.5 * (*(xp0 + 2) + *xp0); ya = 0.5 * (*ype + *yp0); yc = 0.5 * (*(yp0 + 2) + *yp0); parabola(xa, ya, xc, yc, *xp0, *yp0); } else { /*open curve with multiple endpoints*/ if (mode % 2) /*odd mode makes first point double*/ plotline(*xp0,*yp0,0.5*(*xp0+*(xp0+2)),0.5*(*yp0+*(yp0+2))); } xp += 2; yp += 2; for (i = 1; i < (n - 1); i++, xp += 2, yp += 2) { xa = 0.5 * (*(xp - 2) + *xp); xc = 0.5 * ( *xp + *(xp + 2)); ya = 0.5 * (*(yp - 2) + *yp); yc = 0.5 * ( *yp + *(yp + 2)); parabola(xa, ya, xc, yc, *xp, *yp); } if(mode >= 2 && mode != 4) plotline(0.5*(*(xpe-2)+*xpe),0.5*(*(ype-2)+*ype),*xpe,*ype); }}
/*
* This file is part of the UCB release of Plan 9. It is subject to the license
* terms in the LICENSE file found in the top-level directory of this
* distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
* part of the UCB release of Plan 9, including this file, may be copied,
* modified, propagated, or distributed except according to the terms contained
* in the LICENSE file.
*/
/*
Produce spline (uniform knots, second order)
from guiding points
*/
#include "mplot.h"
void splin(int mode, int num[], double *ff[]){
int i, *np, n;
double xa, ya, xc, yc, *xp, *yp, *xp0, *yp0, *xpe, *ype;
double **fp;
np = num;
fp = ff;
while((n = *np++)){
xp = *fp++;
yp = xp + 1;
xp0 = xp;
yp0 = yp;
xpe = xp0 + 2 * (n - 1);
ype = yp0 + 2 * (n - 1);
if (n < 3) {
plotline(*xp, *yp, *(xp + 2), *(yp + 2));
continue;
}
if (mode == 4) { /*closed curve*/
xa = 0.5 * (*xpe + *(xpe - 2));
xc = 0.5 * (*xpe + *xp0);
ya = 0.5 * (*ype + *(ype - 2));
yc = 0.5 * (*ype + *yp0);
parabola(xa, ya, xc, yc, *xpe, *ype);
xa = 0.5 * (*xpe + *xp0);
xc = 0.5 * (*(xp0 + 2) + *xp0);
ya = 0.5 * (*ype + *yp0);
yc = 0.5 * (*(yp0 + 2) + *yp0);
parabola(xa, ya, xc, yc, *xp0, *yp0);
}
else { /*open curve with multiple endpoints*/
if (mode % 2) /*odd mode makes first point double*/
plotline(*xp0,*yp0,0.5*(*xp0+*(xp0+2)),0.5*(*yp0+*(yp0+2)));
}
xp += 2;
yp += 2;
for (i = 1; i < (n - 1); i++, xp += 2, yp += 2) {
xa = 0.5 * (*(xp - 2) + *xp);
xc = 0.5 * ( *xp + *(xp + 2));
ya = 0.5 * (*(yp - 2) + *yp);
yc = 0.5 * ( *yp + *(yp + 2));
parabola(xa, ya, xc, yc, *xp, *yp);
}
if(mode >= 2 && mode != 4)
plotline(0.5*(*(xpe-2)+*xpe),0.5*(*(ype-2)+*ype),*xpe,*ype);
}
}