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#ifndef lint |
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static const char RCSid[] = "$Id: genprism.c,v 2.14 2025/06/07 05:09:45 greg Exp $"; |
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#endif |
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/* |
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* genprism.c - generate a prism. |
| 6 |
* 2D vertices in the xy plane are given on the |
| 7 |
* command line or from a file. Their order together |
| 8 |
* with the extrude direction will determine surface |
| 9 |
* orientation. |
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*/ |
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|
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#include "rtio.h" |
| 13 |
#include "paths.h" |
| 14 |
#include <math.h> |
| 15 |
#include <ctype.h> |
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|
| 17 |
#define MAXVERT 1024 /* maximum # vertices */ |
| 18 |
|
| 19 |
#define FTINY 1e-6 |
| 20 |
|
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char *pmtype; /* material type */ |
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char *pname; /* name */ |
| 23 |
|
| 24 |
double lvect[3] = {0.0, 0.0, 1.0}; |
| 25 |
int lvdir = 1; |
| 26 |
double llen = 1.0; |
| 27 |
|
| 28 |
double vert[MAXVERT][2]; |
| 29 |
int nverts = 0; |
| 30 |
|
| 31 |
double u[MAXVERT][2]; /* edge unit vectors */ |
| 32 |
double a[MAXVERT]; /* corner trim sizes */ |
| 33 |
|
| 34 |
int do_ends = 1; /* include end caps */ |
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int iscomplete = 0; /* polygon is already completed */ |
| 36 |
double crad = 0.0; /* radius for corners (sign from lvdir) */ |
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|
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|
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void |
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readverts(char *fname) /* read vertices from a file */ |
| 41 |
{ |
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FILE *fp; |
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|
| 44 |
if (fname == NULL) { |
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fp = stdin; |
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fname = "<stdin>"; |
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} else if ((fp = fopen(fname, "r")) == NULL) { |
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fprintf(stderr, "%s: cannot open\n", fname); |
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exit(1); |
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} |
| 51 |
while (fscanf(fp, "%lf %lf", &vert[nverts][0], &vert[nverts][1]) == 2) |
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if (++nverts >= MAXVERT) |
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break; |
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|
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if (!feof(fp)) { |
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if (nverts < MAXVERT) { |
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fprintf(stderr, "%s: warning - non-numerical data\n", fname); |
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} else { |
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fprintf(stderr, "%s: too many vertices\n", fname); |
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exit(1); |
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} |
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} |
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fclose(fp); |
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} |
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|
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|
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void |
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side(int n0, int n1) /* print single side */ |
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{ |
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printf("\n%s polygon %s.%d\n", pmtype, pname, n0+1); |
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printf("0\n0\n12\n"); |
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printf("\t%18.12g\t%18.12g\t%18.12g\n", vert[n0][0], |
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vert[n0][1], 0.0); |
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printf("\t%18.12g\t%18.12g\t%18.12g\n", vert[n0][0]+lvect[0], |
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vert[n0][1]+lvect[1], lvect[2]); |
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printf("\t%18.12g\t%18.12g\t%18.12g\n", vert[n1][0]+lvect[0], |
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vert[n1][1]+lvect[1], lvect[2]); |
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printf("\t%18.12g\t%18.12g\t%18.12g\n", vert[n1][0], |
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vert[n1][1], 0.0); |
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} |
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|
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|
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void |
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rside(int n0, int n1) /* print side with rounded edge */ |
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{ |
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double s, c, t[3]; |
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|
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/* compute tanget offset vector */ |
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s = lvdir*(lvect[1]*u[n1][0] - lvect[0]*u[n1][1])/llen; |
| 90 |
if (s < -FTINY || s > FTINY) { |
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c = sqrt(1. - s*s); |
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t[0] = (c - 1.)*u[n1][1]; |
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t[1] = (1. - c)*u[n1][0]; |
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t[2] = s; |
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} else |
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t[0] = t[1] = t[2] = 0.; |
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/* output side */ |
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printf("\n%s polygon %s.%d\n", pmtype, pname, n0+1); |
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printf("0\n0\n12\n"); |
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printf("\t%18.12g\t%18.12g\t%18.12g\n", |
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vert[n0][0] + crad*(t[0] - a[n0]*u[n1][0]), |
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vert[n0][1] + crad*(t[1] - a[n0]*u[n1][1]), |
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crad*(t[2] + 1.)); |
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printf("\t%18.12g\t%18.12g\t%18.12g\n", |
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vert[n0][0] + lvect[0] + crad*(t[0] - a[n0]*u[n1][0]), |
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vert[n0][1] + lvect[1] + crad*(t[1] - a[n0]*u[n1][1]), |
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lvect[2] + crad*(t[2] - 1.)); |
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printf("\t%18.12g\t%18.12g\t%18.12g\n", |
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vert[n1][0] + lvect[0] + crad*(t[0] + a[n1]*u[n1][0]), |
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vert[n1][1] + lvect[1] + crad*(t[1] + a[n1]*u[n1][1]), |
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lvect[2] + crad*(t[2] - 1.)); |
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printf("\t%18.12g\t%18.12g\t%18.12g\n", |
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vert[n1][0] + crad*(t[0] + a[n1]*u[n1][0]), |
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vert[n1][1] + crad*(t[1] + a[n1]*u[n1][1]), |
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crad*(t[2] + 1.)); |
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/* output joining edge */ |
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if (lvdir*a[n1] < 0.) |
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return; |
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printf("\n%s cylinder %s.e%d\n", pmtype, pname, n0+1); |
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printf("0\n0\n7\n"); |
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printf("\t%18.12g\t%18.12g\t%18.12g\n", |
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vert[n1][0] + crad*(a[n1]*u[n1][0] - u[n1][1]), |
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vert[n1][1] + crad*(a[n1]*u[n1][1] + u[n1][0]), |
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crad); |
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printf("\t%18.12g\t%18.12g\t%18.12g\n", |
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vert[n1][0] + lvect[0] + crad*(a[n1]*u[n1][0] - u[n1][1]), |
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vert[n1][1] + lvect[1] + crad*(a[n1]*u[n1][1] + u[n1][0]), |
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lvect[2] - crad); |
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printf("\t%18.12g\n", lvdir*crad); |
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} |
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|
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|
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double |
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compute_rounding() /* compute vectors for rounding operations */ |
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{ |
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int i; |
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double *v0, *v1; |
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double l, asum; |
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|
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v0 = vert[nverts-1]; |
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for (i = 0; i < nverts; i++) { /* compute u[*] */ |
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v1 = vert[i]; |
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u[i][0] = v0[0] - v1[0]; |
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u[i][1] = v0[1] - v1[1]; |
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l = sqrt(u[i][0]*u[i][0] + u[i][1]*u[i][1]); |
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if (l <= FTINY) { |
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fprintf(stderr, "Degenerate side in prism\n"); |
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exit(1); |
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} |
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u[i][0] /= l; |
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u[i][1] /= l; |
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v0 = v1; |
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} |
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asum = 0.; |
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v1 = u[0]; |
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for (i = nverts; i--; ) { /* compute a[*] */ |
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v0 = u[i]; |
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l = v0[0]*v1[0] + v0[1]*v1[1]; |
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if (1+l <= FTINY) { |
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fprintf(stderr, "Overlapping sides in prism\n"); |
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exit(1); |
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} |
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if (1-l <= 0.) |
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a[i] = 0.; |
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else { |
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a[i] = sqrt((1-l)/(1+l)); |
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asum += l = v1[0]*v0[1]-v1[1]*v0[0]; |
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if (l < 0.) |
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a[i] = -a[i]; |
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} |
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v1 = v0; |
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} |
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return(asum*.5); |
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} |
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|
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|
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void |
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printends() /* print ends of prism */ |
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{ |
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int i; |
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/* bottom face */ |
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printf("\n%s polygon %s.b\n", pmtype, pname); |
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printf("0\n0\n%d\n", nverts*3); |
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for (i = 0; i < nverts; i++) |
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printf("\t%18.12g\t%18.12g\t%18.12g\n", vert[i][0], |
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vert[i][1], 0.0); |
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/* top face */ |
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printf("\n%s polygon %s.t\n", pmtype, pname); |
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printf("0\n0\n%d\n", nverts*3); |
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for (i = nverts; i--; ) |
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printf("\t%18.12g\t%18.12g\t%18.12g\n", vert[i][0]+lvect[0], |
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vert[i][1]+lvect[1], lvect[2]); |
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} |
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|
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|
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void |
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printrends() /* print ends of prism with rounding */ |
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{ |
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int i; |
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double c0[3], c1[3], cl[3]; |
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/* bottom face */ |
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printf("\n%s polygon %s.b\n", pmtype, pname); |
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printf("0\n0\n%d\n", nverts*3); |
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for (i = 0; i < nverts; i++) { |
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printf("\t%18.12g\t%18.12g\t%18.12g\n", |
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vert[i][0] + crad*(a[i]*u[i][0] - u[i][1]), |
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vert[i][1] + crad*(a[i]*u[i][1] + u[i][0]), |
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0.0); |
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} |
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/* top face */ |
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printf("\n%s polygon %s.t\n", pmtype, pname); |
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printf("0\n0\n%d\n", nverts*3); |
| 213 |
for (i = nverts; i--; ) { |
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printf("\t%18.12g\t%18.12g\t%18.12g\n", |
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vert[i][0] + lvect[0] + crad*(a[i]*u[i][0] - u[i][1]), |
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vert[i][1] + lvect[1] + crad*(a[i]*u[i][1] + u[i][0]), |
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lvect[2]); |
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} |
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/* bottom corners and edges */ |
| 220 |
c0[0] = cl[0] = vert[nverts-1][0] + |
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crad*(a[nverts-1]*u[nverts-1][0] - u[nverts-1][1]); |
| 222 |
c0[1] = cl[1] = vert[nverts-1][1] + |
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crad*(a[nverts-1]*u[nverts-1][1] + u[nverts-1][0]); |
| 224 |
c0[2] = cl[2] = crad; |
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for (i = 0; i < nverts; i++) { |
| 226 |
if (i < nverts-1) { |
| 227 |
c1[0] = vert[i][0] + crad*(a[i]*u[i][0] - u[i][1]); |
| 228 |
c1[1] = vert[i][1] + crad*(a[i]*u[i][1] + u[i][0]); |
| 229 |
c1[2] = crad; |
| 230 |
} else { |
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c1[0] = cl[0]; c1[1] = cl[1]; c1[2] = cl[2]; |
| 232 |
} |
| 233 |
if (lvdir*a[i] > 0.) { |
| 234 |
printf("\n%s sphere %s.bc%d\n", pmtype, pname, i+1); |
| 235 |
printf("0\n0\n4 %18.12g %18.12g %18.12g %18.12g\n", |
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c1[0], c1[1], c1[2], lvdir*crad); |
| 237 |
} |
| 238 |
printf("\n%s cylinder %s.be%d\n", pmtype, pname, i+1); |
| 239 |
printf("0\n0\n7\n"); |
| 240 |
printf("\t%18.12g\t%18.12g\t%18.12g\n", c0[0], c0[1], c0[2]); |
| 241 |
printf("\t%18.12g\t%18.12g\t%18.12g\n", c1[0], c1[1], c1[2]); |
| 242 |
printf("\t%18.12g\n", lvdir*crad); |
| 243 |
c0[0] = c1[0]; c0[1] = c1[1]; c0[2] = c1[2]; |
| 244 |
} |
| 245 |
/* top corners and edges */ |
| 246 |
c0[0] = cl[0] = vert[nverts-1][0] + lvect[0] + |
| 247 |
crad*(a[nverts-1]*u[nverts-1][0] - u[nverts-1][1]); |
| 248 |
c0[1] = cl[1] = vert[nverts-1][1] + lvect[1] + |
| 249 |
crad*(a[nverts-1]*u[nverts-1][1] + u[nverts-1][0]); |
| 250 |
c0[2] = cl[2] = lvect[2] - crad; |
| 251 |
for (i = 0; i < nverts; i++) { |
| 252 |
if (i < nverts-1) { |
| 253 |
c1[0] = vert[i][0] + lvect[0] + |
| 254 |
crad*(a[i]*u[i][0] - u[i][1]); |
| 255 |
c1[1] = vert[i][1] + lvect[1] + |
| 256 |
crad*(a[i]*u[i][1] + u[i][0]); |
| 257 |
c1[2] = lvect[2] - crad; |
| 258 |
} else { |
| 259 |
c1[0] = cl[0]; c1[1] = cl[1]; c1[2] = cl[2]; |
| 260 |
} |
| 261 |
if (lvdir*a[i] > 0.) { |
| 262 |
printf("\n%s sphere %s.tc%d\n", pmtype, pname, i+1); |
| 263 |
printf("0\n0\n4 %18.12g %18.12g %18.12g %18.12g\n", |
| 264 |
c1[0], c1[1], c1[2], lvdir*crad); |
| 265 |
} |
| 266 |
printf("\n%s cylinder %s.te%d\n", pmtype, pname, i+1); |
| 267 |
printf("0\n0\n7\n"); |
| 268 |
printf("\t%18.12g\t%18.12g\t%18.12g\n", c0[0], c0[1], c0[2]); |
| 269 |
printf("\t%18.12g\t%18.12g\t%18.12g\n", c1[0], c1[1], c1[2]); |
| 270 |
printf("\t%18.12g\n", lvdir*crad); |
| 271 |
c0[0] = c1[0]; c0[1] = c1[1]; c0[2] = c1[2]; |
| 272 |
} |
| 273 |
} |
| 274 |
|
| 275 |
|
| 276 |
void |
| 277 |
printsides(int round) /* print prism sides */ |
| 278 |
{ |
| 279 |
int i; |
| 280 |
|
| 281 |
for (i = 0; i < nverts-1; i++) |
| 282 |
if (round) |
| 283 |
rside(i, i+1); |
| 284 |
else |
| 285 |
side(i, i+1); |
| 286 |
if (!iscomplete) { |
| 287 |
if (round) |
| 288 |
rside(nverts-1, 0); |
| 289 |
else |
| 290 |
side(nverts-1, 0); |
| 291 |
} |
| 292 |
} |
| 293 |
|
| 294 |
|
| 295 |
int |
| 296 |
main(int argc, char **argv) |
| 297 |
{ |
| 298 |
int an; |
| 299 |
|
| 300 |
if (argc < 4) |
| 301 |
goto userr; |
| 302 |
|
| 303 |
pmtype = argv[1]; |
| 304 |
pname = argv[2]; |
| 305 |
|
| 306 |
if (!strcmp(argv[3], "-")) { |
| 307 |
readverts(NULL); |
| 308 |
an = 4; |
| 309 |
} else if (isdigit(argv[3][0])) { |
| 310 |
nverts = atoi(argv[3]); |
| 311 |
if (argc-3 < 2*nverts) |
| 312 |
goto userr; |
| 313 |
if (nverts > MAXVERT) { |
| 314 |
fprintf(stderr, "%s: too many vertices\n", argv[0]); |
| 315 |
return(1); |
| 316 |
} |
| 317 |
for (an = 0; an < nverts; an++) { |
| 318 |
vert[an][0] = atof(argv[2*an+4]); |
| 319 |
vert[an][1] = atof(argv[2*an+5]); |
| 320 |
} |
| 321 |
an = 2*nverts+4; |
| 322 |
} else { |
| 323 |
readverts(argv[3]); |
| 324 |
an = 4; |
| 325 |
} |
| 326 |
if (nverts < 3) { |
| 327 |
fprintf(stderr, "%s: not enough vertices\n", argv[0]); |
| 328 |
return(1); |
| 329 |
} |
| 330 |
|
| 331 |
for ( ; an < argc; an++) { |
| 332 |
if (argv[an][0] != '-') |
| 333 |
goto userr; |
| 334 |
switch (argv[an][1]) { |
| 335 |
case 'l': /* length vector */ |
| 336 |
lvect[0] = atof(argv[++an]); |
| 337 |
lvect[1] = atof(argv[++an]); |
| 338 |
lvect[2] = atof(argv[++an]); |
| 339 |
if (lvect[2] < -FTINY) |
| 340 |
lvdir = -1; |
| 341 |
else if (lvect[2] > FTINY) |
| 342 |
lvdir = 1; |
| 343 |
else { |
| 344 |
fprintf(stderr, |
| 345 |
"%s: illegal extrusion vector\n", |
| 346 |
argv[0]); |
| 347 |
return(1); |
| 348 |
} |
| 349 |
llen = sqrt(lvect[0]*lvect[0] + lvect[1]*lvect[1] + |
| 350 |
lvect[2]*lvect[2]); |
| 351 |
break; |
| 352 |
case 'r': /* radius */ |
| 353 |
crad = atof(argv[++an]); |
| 354 |
break; |
| 355 |
case 'e': /* ends */ |
| 356 |
do_ends = !do_ends; |
| 357 |
break; |
| 358 |
case 'c': /* complete */ |
| 359 |
iscomplete = !iscomplete; |
| 360 |
break; |
| 361 |
default: |
| 362 |
goto userr; |
| 363 |
} |
| 364 |
} |
| 365 |
if (crad > FTINY) { |
| 366 |
if (crad > lvdir*lvect[2]) { |
| 367 |
fprintf(stderr, "%s: rounding greater than height\n", |
| 368 |
argv[0]); |
| 369 |
return(1); |
| 370 |
} |
| 371 |
crad *= lvdir; /* simplifies formulas */ |
| 372 |
compute_rounding(); |
| 373 |
fputs("# ", stdout); |
| 374 |
printargs(argc, argv, stdout); |
| 375 |
if (do_ends) |
| 376 |
printrends(); |
| 377 |
printsides(1); |
| 378 |
} else { |
| 379 |
fputs("# ", stdout); |
| 380 |
printargs(argc, argv, stdout); |
| 381 |
if (do_ends) |
| 382 |
printends(); |
| 383 |
printsides(0); |
| 384 |
} |
| 385 |
return(0); |
| 386 |
userr: |
| 387 |
fprintf(stderr, "Usage: %s material name ", argv[0]); |
| 388 |
fprintf(stderr, "{ - | vfile | N v1 v2 .. vN } "); |
| 389 |
fprintf(stderr, "[-l lvect][-r radius][-c][-e]\n"); |
| 390 |
return(1); |
| 391 |
} |
| 392 |
|
