| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id$"; |
| 3 |
#endif |
| 4 |
/* |
| 5 |
* genrev.c - program to generate functions of rotation about z |
| 6 |
* |
| 7 |
* The program takes as input the functions of t for z and r |
| 8 |
* (the radius). If z is increasing, the normal points |
| 9 |
* outward, inward for decreasing z. Negative radii are forbidden. |
| 10 |
* |
| 11 |
* 8/6/86 |
| 12 |
*/ |
| 13 |
|
| 14 |
#include <stdio.h> |
| 15 |
#include <math.h> |
| 16 |
|
| 17 |
#define ZNAME "Z`SYS`" /* z function name */ |
| 18 |
#define RNAME "R`SYS`" /* r function name */ |
| 19 |
|
| 20 |
#define PI 3.14159265358979323846 |
| 21 |
|
| 22 |
#define FTINY 1e-9 |
| 23 |
/* orientation */ |
| 24 |
#define OUT 01 |
| 25 |
#define IN 02 |
| 26 |
#define UP 04 |
| 27 |
#define DOWN 010 |
| 28 |
|
| 29 |
double funvalue(), l_hermite(), l_bezier(), l_bspline(), argument(); |
| 30 |
|
| 31 |
void quit(), eputs(), wputs(); |
| 32 |
|
| 33 |
|
| 34 |
main(argc, argv) |
| 35 |
int argc; |
| 36 |
char *argv[]; |
| 37 |
{ |
| 38 |
extern long eclock; |
| 39 |
char stmp[256]; |
| 40 |
char *modname; |
| 41 |
int smooth = 0; |
| 42 |
double t, lastz, z, nextz, lastr, r, nextr; |
| 43 |
double lastnz, lastnr, nz, nr, nextnz, nextnr; |
| 44 |
int i, nseg; |
| 45 |
int orient; |
| 46 |
|
| 47 |
varset("PI", ':', PI); |
| 48 |
funset("hermite", 5, ':', l_hermite); |
| 49 |
funset("bezier", 5, ':', l_bezier); |
| 50 |
funset("bspline", 5, ':', l_bspline); |
| 51 |
|
| 52 |
if (argc < 6) |
| 53 |
goto userror; |
| 54 |
|
| 55 |
for (i = 6; i < argc; i++) |
| 56 |
if (!strcmp(argv[i], "-e")) |
| 57 |
scompile(argv[++i], NULL, 0); |
| 58 |
else if (!strcmp(argv[i], "-f")) |
| 59 |
fcompile(argv[++i]); |
| 60 |
else if (!strcmp(argv[i], "-s")) |
| 61 |
smooth = 1; |
| 62 |
else |
| 63 |
goto userror; |
| 64 |
|
| 65 |
sprintf(stmp, "%s(t)=%s;", ZNAME, argv[3]); |
| 66 |
scompile(stmp, NULL, 0); |
| 67 |
sprintf(stmp, "%s(t)=%s;", RNAME, argv[4]); |
| 68 |
scompile(stmp, NULL, 0); |
| 69 |
nseg = atoi(argv[5]); |
| 70 |
if (nseg <= 0) |
| 71 |
goto userror; |
| 72 |
modname = smooth ? "Phong" : argv[1]; |
| 73 |
|
| 74 |
printhead(argc, argv); |
| 75 |
eclock = 0; |
| 76 |
|
| 77 |
lastnz = lastnr = 0.0; |
| 78 |
t = 0.0; |
| 79 |
lastz = funvalue(ZNAME, 1, &t); |
| 80 |
lastr = funvalue(RNAME, 1, &t); |
| 81 |
t = 1.0/nseg; |
| 82 |
z = funvalue(ZNAME, 1, &t); |
| 83 |
r = funvalue(RNAME, 1, &t); |
| 84 |
computen(&nz, &nr, lastz, lastr, z, r); |
| 85 |
for (i = 1; i <= nseg; i++) { |
| 86 |
if (i < nseg) { |
| 87 |
t = (double)(i+1)/nseg; |
| 88 |
nextz = funvalue(ZNAME, 1, &t); |
| 89 |
nextr = funvalue(RNAME, 1, &t); |
| 90 |
computen(&nextnz, &nextnr, z, r, nextz, nextr); |
| 91 |
} else |
| 92 |
nextnz = nextnr = 0.0; |
| 93 |
orient = 0; |
| 94 |
if (z < lastz-FTINY) |
| 95 |
orient |= DOWN; |
| 96 |
else if (z > lastz+FTINY) |
| 97 |
orient |= UP; |
| 98 |
if (r < lastr-FTINY) |
| 99 |
orient |= IN; |
| 100 |
else if (r > lastr+FTINY) |
| 101 |
orient |= OUT; |
| 102 |
if (!orient) |
| 103 |
goto endfor; |
| 104 |
if (smooth) { |
| 105 |
printf("\n%s texfunc Phong\n", argv[1]); |
| 106 |
printf("4 rev_dx rev_dy rev_dz rev.cal\n"); |
| 107 |
printf("0\n4\n"); |
| 108 |
if (orient&(UP|DOWN)) { |
| 109 |
t = (nextnz - lastnz)/(z - lastz); |
| 110 |
printf("\t%15.9g\t%15.9g\n", |
| 111 |
t, lastnz - t*lastz); |
| 112 |
} else |
| 113 |
printf("\t0\t%d\n", orient&IN ? 1 : -1); |
| 114 |
if (orient&(OUT|IN)) { |
| 115 |
t = (nextnr - lastnr)/(r - lastr); |
| 116 |
printf("\t%15.9g\t%15.9g\n", |
| 117 |
t, lastnr - t*lastr); |
| 118 |
} else |
| 119 |
printf("\t0\t%d\n", orient&UP ? 1 : -1); |
| 120 |
} |
| 121 |
if (!(orient&(IN|OUT))) { |
| 122 |
printf("\n%s %s %s.%d\n", modname, |
| 123 |
orient&DOWN ? "tube" : "cylinder", |
| 124 |
argv[2], i); |
| 125 |
printf("0\n0\n7\n"); |
| 126 |
printf("\t0\t0\t%15.9g\n", lastz); |
| 127 |
printf("\t0\t0\t%15.9g\n", z); |
| 128 |
printf("\t%15.9g\n", r); |
| 129 |
} else if (!(orient&(UP|DOWN))) { |
| 130 |
printf("\n%s ring %s.%d\n", modname, argv[2], i); |
| 131 |
printf("0\n0\n8\n"); |
| 132 |
printf("\t0\t0\t%15.9g\n", z); |
| 133 |
printf("\t0\t0\t%15.9g\n", orient&IN ? 1.0 : -1.0); |
| 134 |
printf("\t%15.9g\t%15.9g\n", lastr, r); |
| 135 |
} else { |
| 136 |
printf("\n%s %s %s.%d\n", modname, |
| 137 |
orient&DOWN ? "cup" : "cone", |
| 138 |
argv[2], i); |
| 139 |
printf("0\n0\n8\n"); |
| 140 |
printf("\t0\t0\t%15.9g\n", lastz); |
| 141 |
printf("\t0\t0\t%15.9g\n", z); |
| 142 |
printf("\t%15.9g\t%15.9g\n", lastr, r); |
| 143 |
} |
| 144 |
endfor: |
| 145 |
lastz = z; lastr = r; |
| 146 |
z = nextz; r = nextr; |
| 147 |
lastnz = nz; lastnr = nr; |
| 148 |
nz = nextnz; nr = nextnr; |
| 149 |
} |
| 150 |
quit(0); |
| 151 |
|
| 152 |
userror: |
| 153 |
fprintf(stderr, |
| 154 |
"Usage: %s material name z(t) r(t) nseg [-e expr] [-f file] [-s]\n", |
| 155 |
argv[0]); |
| 156 |
quit(1); |
| 157 |
} |
| 158 |
|
| 159 |
|
| 160 |
computen(nzp, nrp, z0, r0, z1, r1) /* compute normal */ |
| 161 |
double *nzp, *nrp, z0, r0, z1, r1; |
| 162 |
{ |
| 163 |
double dr, dz, len; |
| 164 |
|
| 165 |
dz = r0 - r1; /* right angle vector */ |
| 166 |
dr = z1 - z0; |
| 167 |
len = sqrt(dr*dr + dz*dz); |
| 168 |
*nzp = dz/len; |
| 169 |
*nrp = dr/len; |
| 170 |
} |
| 171 |
|
| 172 |
|
| 173 |
void |
| 174 |
eputs(msg) |
| 175 |
char *msg; |
| 176 |
{ |
| 177 |
fputs(msg, stderr); |
| 178 |
} |
| 179 |
|
| 180 |
|
| 181 |
void |
| 182 |
wputs(msg) |
| 183 |
char *msg; |
| 184 |
{ |
| 185 |
eputs(msg); |
| 186 |
} |
| 187 |
|
| 188 |
|
| 189 |
void |
| 190 |
quit(code) |
| 191 |
int code; |
| 192 |
{ |
| 193 |
exit(code); |
| 194 |
} |
| 195 |
|
| 196 |
|
| 197 |
printhead(ac, av) /* print command header */ |
| 198 |
register int ac; |
| 199 |
register char **av; |
| 200 |
{ |
| 201 |
putchar('#'); |
| 202 |
while (ac--) { |
| 203 |
putchar(' '); |
| 204 |
fputs(*av++, stdout); |
| 205 |
} |
| 206 |
putchar('\n'); |
| 207 |
} |
| 208 |
|
| 209 |
|
| 210 |
double |
| 211 |
l_hermite() |
| 212 |
{ |
| 213 |
double t; |
| 214 |
|
| 215 |
t = argument(5); |
| 216 |
return( argument(1)*((2.0*t-3.0)*t*t+1.0) + |
| 217 |
argument(2)*(-2.0*t+3.0)*t*t + |
| 218 |
argument(3)*((t-2.0)*t+1.0)*t + |
| 219 |
argument(4)*(t-1.0)*t*t ); |
| 220 |
} |
| 221 |
|
| 222 |
|
| 223 |
double |
| 224 |
l_bezier() |
| 225 |
{ |
| 226 |
double t; |
| 227 |
|
| 228 |
t = argument(5); |
| 229 |
return( argument(1) * (1.+t*(-3.+t*(3.-t))) + |
| 230 |
argument(2) * 3.*t*(1.+t*(-2.+t)) + |
| 231 |
argument(3) * 3.*t*t*(1.-t) + |
| 232 |
argument(4) * t*t*t ); |
| 233 |
} |
| 234 |
|
| 235 |
|
| 236 |
double |
| 237 |
l_bspline() |
| 238 |
{ |
| 239 |
double t; |
| 240 |
|
| 241 |
t = argument(5); |
| 242 |
return( argument(1) * (1./6.+t*(-1./2.+t*(1./2.-1./6.*t))) + |
| 243 |
argument(2) * (2./3.+t*t*(-1.+1./2.*t)) + |
| 244 |
argument(3) * (1./6.+t*(1./2.+t*(1./2.-1./2.*t))) + |
| 245 |
argument(4) * (1./6.*t*t*t) ); |
| 246 |
} |
