src/gen/genworm.c

#ifndef lint
static char SCCSid[] = "$SunId$ LBL";
#endif

/* Copyright (c) 1989 Regents of the University of California */

/*
 *  genworm.c - program to generate worms (strings with varying thickness).
 *
 *      The program takes as input the functions of t for x, y,
 *      z and r (the radius).  Cylinders and cones will be
 *      joined by spheres.  Negative radii are forbidden.
 *
 *      9/24/87
 */

#include  <stdio.h>

#include  "fvect.h"

#define  XNAME          "X_"                    /* x function name */
#define  YNAME          "Y_"                    /* y function name */
#define  ZNAME          "Z_"                    /* z function name */
#define  RNAME          "R_"                    /* r function name */

#define  PI             3.14159265358979323846

#define  FTINY          1e-7

#define  max(a,b)       ((a) > (b) ? (a) : (b))


double  funvalue(), l_hermite(), l_bezier(), l_bspline(), argument();


main(argc, argv)
int  argc;
char  *argv[];
{
        char  stmp[256];
        double  t, f, lastr, r;
        FVECT  lastp, p;
        int  i, nseg;

        varset("PI", PI, NULL);
        funset("hermite", 5, l_hermite);
        funset("bezier", 5, l_bezier);
        funset("bspline", 5, l_bspline);

        if (argc < 8)
                goto userror;

        for (i = 8; i < argc; i++)
                if (!strcmp(argv[i], "-e"))
                        scompile(NULL, argv[++i]);
                else if (!strcmp(argv[i], "-f"))
                        fcompile(argv[++i]);
                else
                        goto userror;

        sprintf(stmp, "%s(t)=%s;", XNAME, argv[3]);
        scompile(NULL, stmp);
        sprintf(stmp, "%s(t)=%s;", YNAME, argv[4]);
        scompile(NULL, stmp);
        sprintf(stmp, "%s(t)=%s;", ZNAME, argv[5]);
        scompile(NULL, stmp);
        sprintf(stmp, "%s(t)=%s;", RNAME, argv[6]);
        scompile(NULL, stmp);
        nseg = atoi(argv[7]);
        if (nseg <= 0)
                goto userror;

        printhead(argc, argv);

        for (i = 0; i <= nseg; i++) {
                t = (double)i/nseg;
                p[0] = funvalue(XNAME, 1, &t);
                p[1] = funvalue(YNAME, 1, &t);
                p[2] = funvalue(ZNAME, 1, &t);
                r = funvalue(RNAME, 1, &t);
                if (i)
                        if (lastr <= r+FTINY && lastr >= r-FTINY) {
                                printf("\n%s cylinder %s.c%d\n",
                                                argv[1], argv[2], i);
                                printf("0\n0\n7\n");
                                printf("%18.12g %18.12g %18.12g\n",
                                                lastp[0], lastp[1], lastp[2]);
                                printf("%18.12g %18.12g %18.12g\n",
                                                p[0], p[1], p[2]);
                                printf("%18.12g\n", r);
                        } else {
                                printf("\n%s cone %s.c%d\n",
                                                argv[1], argv[2], i);
                                printf("0\n0\n8\n");
                                f = (lastr - r)/dist2(lastp,p);
                                printf("%18.12g %18.12g %18.12g\n",
                                        lastp[0] + f*lastr*(p[0] - lastp[0]),
                                        lastp[1] + f*lastr*(p[1] - lastp[1]),
                                        lastp[2] + f*lastr*(p[2] - lastp[2]));
                                printf("%18.12g %18.12g %18.12g\n",
                                        p[0] + f*r*(p[0] - lastp[0]),
                                        p[1] + f*r*(p[1] - lastp[1]),
                                        p[2] + f*r*(p[2] - lastp[2]));
                                f = 1.0 - (lastr-r)*f;
                                f = f <= 0.0 ? 0.0 : sqrt(f);
                                printf("%18.12g %18.12g\n", f*lastr, f*r);
                        }
                printf("\n%s sphere %s.s%d\n", argv[1], argv[2], i);
                printf("0\n0\n4 %18.12g %18.12g %18.12g %18.12g\n",
                                p[0], p[1], p[2], r);
                VCOPY(lastp, p);
                lastr = r;
        }
        quit(0);

userror:
        fprintf(stderr,
"Usage: %s material name x(t) y(t) z(t) r(t) nseg [-e expr] [-f file]\n",
                        argv[0]);
        quit(1);
}


eputs(msg)
char  *msg;
{
        fputs(msg, stderr);
}


wputs(msg)
char  *msg;
{
        eputs(msg);
}


quit(code)
{
        exit(code);
}


printhead(ac, av)               /* print command header */
register int  ac;
register char  **av;
{
        putchar('#');
        while (ac--) {
                putchar(' ');
                fputs(*av++, stdout);
        }
        putchar('\n');
}


double
l_hermite()                     
{
        double  t;
        
        t = argument(5);
        return( argument(1)*((2.0*t-3.0)*t*t+1.0) +
                argument(2)*(-2.0*t+3.0)*t*t +
                argument(3)*((t-2.0)*t+1.0)*t +
                argument(4)*(t-1.0)*t*t );
}


double
l_bezier()
{
        double  t;

        t = argument(5);
        return( argument(1) * (1.+t*(-3.+t*(3.-t))) +
                argument(2) * 3.*t*(1.+t*(-2.+t)) +
                argument(3) * 3.*t*t*(1.-t) +
                argument(4) * t*t*t );
}


double
l_bspline()
{
        double  t;

        t = argument(5);
        return( argument(1) * (1./6.+t*(-1./2.+t*(1./2.-1./6.*t))) +
                argument(2) * (2./3.+t*t*(-1.+1./2.*t)) +
                argument(3) * (1./6.+t*(1./2.+t*(1./2.-1./2.*t))) +
                argument(4) * (1./6.*t*t*t) );
}
Revision:	1.4
Committed:	Wed Mar 7 11:14:39 1990 UTC (34 years, 1 month ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.3:	+17 -3 lines
Log Message:	added bezier and bspline functions
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2			static char SCCSid[] = "$SunId$ LBL";
3			#endif
4	greg	1.2
5	greg	1.4	/* Copyright (c) 1989 Regents of the University of California */
6
7	greg	1.2	/*
8	greg	1.1	* genworm.c - program to generate worms (strings with varying thickness).
9			*
10			* The program takes as input the functions of t for x, y,
11			* z and r (the radius). Cylinders and cones will be
12			* joined by spheres. Negative radii are forbidden.
13			*
14			* 9/24/87
15			*/
16
17			#include <stdio.h>
18
19			#include "fvect.h"
20
21			#define XNAME "X_" /* x function name */
22			#define YNAME "Y_" /* y function name */
23			#define ZNAME "Z_" /* z function name */
24			#define RNAME "R_" /* r function name */
25
26			#define PI 3.14159265358979323846
27
28			#define FTINY 1e-7
29
30			#define max(a,b) ((a) > (b) ? (a) : (b))
31
32
33	greg	1.4	double funvalue(), l_hermite(), l_bezier(), l_bspline(), argument();
34	greg	1.1
35
36			main(argc, argv)
37			int argc;
38			char *argv[];
39			{
40			char stmp[256];
41			double t, f, lastr, r;
42			FVECT lastp, p;
43			int i, nseg;
44
45			varset("PI", PI, NULL);
46			funset("hermite", 5, l_hermite);
47	greg	1.3	funset("bezier", 5, l_bezier);
48	greg	1.4	funset("bspline", 5, l_bspline);
49	greg	1.1
50			if (argc < 8)
51			goto userror;
52
53			for (i = 8; i < argc; i++)
54			if (!strcmp(argv[i], "-e"))
55			scompile(NULL, argv[++i]);
56			else if (!strcmp(argv[i], "-f"))
57			fcompile(argv[++i]);
58			else
59			goto userror;
60
61			sprintf(stmp, "%s(t)=%s;", XNAME, argv[3]);
62			scompile(NULL, stmp);
63			sprintf(stmp, "%s(t)=%s;", YNAME, argv[4]);
64			scompile(NULL, stmp);
65			sprintf(stmp, "%s(t)=%s;", ZNAME, argv[5]);
66			scompile(NULL, stmp);
67			sprintf(stmp, "%s(t)=%s;", RNAME, argv[6]);
68			scompile(NULL, stmp);
69			nseg = atoi(argv[7]);
70			if (nseg <= 0)
71			goto userror;
72
73			printhead(argc, argv);
74
75			for (i = 0; i <= nseg; i++) {
76			t = (double)i/nseg;
77			p[0] = funvalue(XNAME, 1, &t);
78			p[1] = funvalue(YNAME, 1, &t);
79			p[2] = funvalue(ZNAME, 1, &t);
80			r = funvalue(RNAME, 1, &t);
81			if (i)
82			if (lastr <= r+FTINY && lastr >= r-FTINY) {
83			printf("\n%s cylinder %s.c%d\n",
84			argv[1], argv[2], i);
85			printf("0\n0\n7\n");
86			printf("%18.12g %18.12g %18.12g\n",
87			lastp[0], lastp[1], lastp[2]);
88			printf("%18.12g %18.12g %18.12g\n",
89			p[0], p[1], p[2]);
90			printf("%18.12g\n", r);
91			} else {
92			printf("\n%s cone %s.c%d\n",
93			argv[1], argv[2], i);
94			printf("0\n0\n8\n");
95			f = (lastr - r)/dist2(lastp,p);
96			printf("%18.12g %18.12g %18.12g\n",
97			lastp[0] + flastr(p[0] - lastp[0]),
98			lastp[1] + flastr(p[1] - lastp[1]),
99			lastp[2] + flastr(p[2] - lastp[2]));
100			printf("%18.12g %18.12g %18.12g\n",
101			p[0] + fr(p[0] - lastp[0]),
102			p[1] + fr(p[1] - lastp[1]),
103			p[2] + fr(p[2] - lastp[2]));
104			f = 1.0 - (lastr-r)*f;
105			f = f <= 0.0 ? 0.0 : sqrt(f);
106			printf("%18.12g %18.12g\n", flastr, fr);
107			}
108			printf("\n%s sphere %s.s%d\n", argv[1], argv[2], i);
109			printf("0\n0\n4 %18.12g %18.12g %18.12g %18.12g\n",
110			p[0], p[1], p[2], r);
111			VCOPY(lastp, p);
112			lastr = r;
113			}
114			quit(0);
115
116			userror:
117			fprintf(stderr,
118			"Usage: %s material name x(t) y(t) z(t) r(t) nseg [-e expr] [-f file]\n",
119			argv[0]);
120			quit(1);
121			}
122
123
124			eputs(msg)
125			char *msg;
126			{
127			fputs(msg, stderr);
128			}
129
130
131			wputs(msg)
132			char *msg;
133			{
134			eputs(msg);
135			}
136
137
138			quit(code)
139			{
140			exit(code);
141			}
142
143
144			printhead(ac, av) /* print command header */
145			register int ac;
146			register char **av;
147			{
148			putchar('#');
149			while (ac--) {
150			putchar(' ');
151			fputs(*av++, stdout);
152			}
153			putchar('\n');
154			}
155
156
157			double
158			l_hermite()
159			{
160			double t;
161
162			t = argument(5);
163			return( argument(1)((2.0t-3.0)tt+1.0) +
164			argument(2)(-2.0t+3.0)tt +
165			argument(3)((t-2.0)t+1.0)*t +
166			argument(4)(t-1.0)t*t );
167	greg	1.3	}
168
169
170			double
171			l_bezier()
172			{
173			double t;
174
175			t = argument(5);
176			return( argument(1) * (1.+t(-3.+t(3.-t))) +
177			argument(2) * 3.t(1.+t*(-2.+t)) +
178			argument(3) * 3.tt*(1.-t) +
179			argument(4) * ttt );
180	greg	1.4	}
181
182
183			double
184			l_bspline()
185			{
186			double t;
187
188			t = argument(5);
189			return( argument(1) * (1./6.+t(-1./2.+t(1./2.-1./6.*t))) +
190			argument(2) * (2./3.+tt(-1.+1./2.*t)) +
191			argument(3) * (1./6.+t(1./2.+t(1./2.-1./2.*t))) +
192			argument(4) * (1./6.tt*t) );
193	greg	1.1	}