src/gen/replmarks.c

#ifndef lint
static const char RCSid[] = "$Id: replmarks.c,v 2.14 2005/12/28 18:35:42 greg Exp $";
#endif
/*
 * Replace markers in Radiance scene description with objects or instances.
 *
 *      Created:        17 Feb 1991     Greg Ward
 */

#include <stdlib.h>
#include <ctype.h>
#include <math.h>
#include <stdio.h>

#include "platform.h"
#include "rtio.h"
#include "rtprocess.h"
#include "fvect.h"

#ifdef  M_PI
#define  PI             ((double)M_PI)
#else
#define  PI             3.14159265358979323846
#endif

#define  FEQ(a,b)       ((a)-(b) <= 1e-7 && (b)-(a) <= 1e-7)

#define  MAXVERT        6       /* maximum number of vertices for markers */
#define  MAXMARK        128     /* maximum number of markers */

#define  USE_XFORM      1       /* use !xform inline command */
#define  USE_INSTANCE   2       /* use instance primitive */
#define  USE_MESH       3       /* use mesh primitive */

typedef struct {
        short   beg, end;               /* beginning and ending vertex */
        float   len2;                   /* length squared */
}  EDGE;                        /* a marker edge */

struct mrkr {
        char    *modout;                /* output modifier */
        double  mscale;                 /* scale by this to get unit */
        char    *modin;                 /* input modifier indicating marker */
        char    *objname;               /* output object file or octree */
        int     usetype;                /* one of USE_* above */
}  marker[MAXMARK+1];           /* array of markers */
int     nmarkers = 0;           /* number of markers */

int     expand;                 /* expand commands? */

char    *progname;

static void convert(char *name, FILE *fin);
static void cvcomm(char *fname, FILE *fin);
static void cvobject(char *fname, FILE *fin);
static void replace(char *fname, struct mrkr *m, char *mark, FILE *fin);
static int edgecmp(const void *e1, const void *e2);
static int buildxf(char *xf, double markscale, FILE *fin);
static int addrot(char *xf, FVECT xp, FVECT yp, FVECT zp);


int
main(
        int     argc,
        char    *argv[]
)
{
        FILE    *fp;
        int     i, j;

        progname = argv[0];
        i = 1;
        while (i < argc && argv[i][0] == '-') {
                do {
                        switch (argv[i][1]) {
                        case 'i':
                                marker[nmarkers].usetype = USE_INSTANCE;
                                marker[nmarkers].objname = argv[++i];
                                break;
                        case 'I':
                                marker[nmarkers].usetype = USE_MESH;
                                marker[nmarkers].objname = argv[++i];
                                break;
                        case 'x':
                                marker[nmarkers].usetype = USE_XFORM;
                                marker[nmarkers].objname = argv[++i];
                                break;
                        case 'e':
                                expand = 1;
                                break;
                        case 'm':
                                marker[nmarkers].modout = argv[++i];
                                break;
                        case 's':
                                marker[nmarkers].mscale = atof(argv[++i]);
                                break;
                        default:
                                goto userr;
                        }
                        if (++i >= argc)
                                goto userr;
                } while (argv[i][0] == '-');
                if (marker[nmarkers].objname == NULL)
                        goto userr;
                if (nmarkers >= MAXMARK) {
                        fprintf(stderr, "%s: too many markers\n", progname);
                        return 1;
                }
                marker[nmarkers++].modin = argv[i++];
                marker[nmarkers].mscale = marker[nmarkers-1].mscale;
        }
        if (nmarkers == 0)
                goto userr;
                                        /* simple header */
        putchar('#');
        for (j = 0; j < i; j++) {
                putchar(' ');
                fputs(argv[j], stdout);
        }
        putchar('\n');
        if (i == argc)
                convert("<stdin>", stdin);
        else
                for ( ; i < argc; i++) {
                        if ((fp = fopen(argv[i], "r")) == NULL) {
                                perror(argv[i]);
                                exit(1);
                        }
                        convert(argv[i], fp);
                        fclose(fp);
                }
        return 0;
userr:
        fprintf(stderr,
"Usage: %s [-e][-s size][-m modout] {-x objfile|-i octree|-I mesh} modname .. [file ..]\n",
                progname);
        return 1;
}


void
convert(                /* replace marks in a stream */
        char    *name,
        register FILE   *fin
)
{
        register int    c;

        while ((c = getc(fin)) != EOF) {
                if (isspace(c))                         /* blank */
                        continue;
                if (c == '#') {                         /* comment */
                        putchar(c);
                        do {
                                if ((c = getc(fin)) == EOF)
                                        return;
                                putchar(c);
                        } while (c != '\n');
                } else if (c == '!') {                  /* command */
                        ungetc(c, fin);
                        cvcomm(name, fin);
                } else {                                /* object */
                        ungetc(c, fin);
                        cvobject(name, fin);
                }
        }
}


void
cvcomm(         /* convert a command */
        char    *fname,
        FILE    *fin
)
{
        FILE    *pin;
        char    buf[512], *fgetline();

        fgetline(buf, sizeof(buf), fin);
        if (expand) {
                if ((pin = popen(buf+1, "r")) == NULL) {
                        fprintf(stderr,
                        "%s: (%s): cannot execute \"%s\"\n",
                                        progname, fname, buf);
                        exit(1);
                }
                convert(buf, pin);
                pclose(pin);
        } else
                printf("\n%s\n", buf);
}


void
cvobject(               /* convert an object */
        char    *fname,
        FILE    *fin
)
{
        extern char     *fgetword();
        char    buf[128], typ[16], nam[128];
        int     i, n;
        register int    j;

        if (fgetword(buf, sizeof(buf), fin) == NULL ||
                        fgetword(typ, sizeof(typ), fin) == NULL ||
                        fgetword(nam, sizeof(nam), fin) == NULL)
                goto readerr;
        if (!strcmp(typ, "polygon"))
                for (j = 0; j < nmarkers; j++)
                        if (!strcmp(buf, marker[j].modin)) {
                                replace(fname, &marker[j], nam, fin);
                                return;
                        }
        putchar('\n'); fputword(buf, stdout);
        printf(" %s ", typ);
        fputword(nam, stdout); putchar('\n');
        if (!strcmp(typ, "alias")) {            /* alias special case */
                if (fgetword(buf, sizeof(buf), fin) == NULL)
                        goto readerr;
                putchar('\t'); fputword(buf, stdout); putchar('\n');
                return;
        }
        for (i = 0; i < 3; i++) {               /* pass along arguments */
                if (fscanf(fin, "%d", &n) != 1)
                        goto readerr;
                printf("%d", n);
                for (j = 0; j < n; j++) {
                        if (fgetword(buf, sizeof(buf), fin) == NULL)
                                goto readerr;
                        if (j%3 == 0)
                                putchar('\n');
                        putchar('\t');
                        fputword(buf, stdout);
                }
                putchar('\n');
        }
        return;
readerr:
        fprintf(stderr, "%s: (%s): read error for %s \"%s\"\n",
                        progname, fname, typ, nam);
}


void
replace(                /* replace marker */
        char    *fname,
        register struct mrkr    *m,
        char    *mark,
        FILE    *fin
)
{
        int     n;
        char    buf[256];

        buf[0] = '\0';                  /* bug fix thanks to schorsch */
        if (m->usetype == USE_XFORM) {
                sprintf(buf, "xform -n %s", mark);
                if (m->modout != NULL)
                        sprintf(buf+strlen(buf), " -m %s", m->modout);
                if (buildxf(buf+strlen(buf), m->mscale, fin) < 0)
                        goto badxf;
                sprintf(buf+strlen(buf), " %s", m->objname);
                if (expand) {
                        fflush(stdout);
                        system(buf);
                } else
                        printf("\n!%s\n", buf);
        } else {
                if ((n = buildxf(buf, m->mscale, fin)) < 0)
                        goto badxf;
                printf("\n%s %s %s\n",
                                m->modout==NULL?"void":m->modout,
                                m->usetype==USE_INSTANCE?"instance":"mesh",
                                mark);
                printf("%d %s%s\n0\n0\n", n+1, m->objname, buf);
        }
        return;
badxf:
        fprintf(stderr, "%s: (%s): bad arguments for marker \"%s\"\n",
                        progname, fname, mark);
        exit(1);
}


int
edgecmp(                        /* compare two edges, descending order */
        const void *e1,
        const void *e2
)
{
        if (((EDGE*)e1)->len2 > ((EDGE*)e2)->len2)
                return(-1);
        if (((EDGE*)e1)->len2 < ((EDGE*)e2)->len2)
                return(1);
        return(0);
}


int
buildxf(                /* build transform for marker */
        register char   *xf,
        double  markscale,
        FILE    *fin
)
{
        static FVECT    vlist[MAXVERT];
        static EDGE     elist[MAXVERT];
        FVECT   xvec, yvec, zvec;
        double  xlen;
        int     n;
        register int    i;
        /*
         * Read and sort vectors:  longest is hypotenuse,
         *      second longest is x' axis,
         *      third longest is y' axis (approximate),
         *      other vectors are ignored.
         * It is an error if the x' and y' axes do
         *      not share a common vertex (their origin).
         */
        if (fscanf(fin, "%*d %*d %d", &n) != 1)
                return(-1);
        if (n%3 != 0)
                return(-1);
        n /= 3;
        if (n < 3 || n > MAXVERT)
                return(-1);
                                        /* sort edges in descending order */
        for (i = 0; i < n; i++) {
                if (fscanf(fin, "%lf %lf %lf", &vlist[i][0],
                                &vlist[i][1], &vlist[i][2]) != 3)
                        return(-1);
                if (i) {
                        elist[i].beg = i-1;
                        elist[i].end = i;
                        elist[i].len2 = dist2(vlist[i-1],vlist[i]);
                }
        }
        elist[0].beg = n-1;
        elist[0].end = 0;
        elist[0].len2 = dist2(vlist[n-1],vlist[0]);
        qsort(elist, n, sizeof(EDGE), edgecmp);
                                        /* find x' and y' */
        if (elist[1].end == elist[2].beg || elist[1].end == elist[2].end) {
                i = elist[1].beg;
                elist[1].beg = elist[1].end;
                elist[1].end = i;
        }
        if (elist[2].end == elist[1].beg) {
                i = elist[2].beg;
                elist[2].beg = elist[2].end;
                elist[2].end = i;
        }
        if (elist[1].beg != elist[2].beg)
                return(-1);             /* x' and y' not connected! */
        for (i = 0; i < 3; i++) {
                xvec[i] = vlist[elist[1].end][i] - vlist[elist[1].beg][i];
                yvec[i] = vlist[elist[2].end][i] - vlist[elist[2].beg][i];
        }
        if ((xlen = normalize(xvec)) == 0.0)
                return(-1);
        fcross(zvec, xvec, yvec);
        if (normalize(zvec) == 0.0)
                return(-1);
        fcross(yvec, zvec, xvec);
        n = 0;                          /* start transformation... */
        if (markscale > 0.0) {          /* add scale factor */
                sprintf(xf, " -s %f", xlen*markscale);
                n += 2;
                while (*xf) ++xf;
        }
                                        /* add rotation */
        n += addrot(xf, xvec, yvec, zvec);
        while (*xf) ++xf;
                                        /* add translation */
        n += 4;
        sprintf(xf, " -t %f %f %f", vlist[elist[1].beg][0],
                        vlist[elist[1].beg][1], vlist[elist[1].beg][2]);
        return(n);                      /* all done */
}


int
addrot(         /* compute rotation (x,y,z) => (xp,yp,zp) */
        register char   *xf,
        FVECT xp,
        FVECT yp,
        FVECT zp
)
{
        int     n;
        double  theta;

        if (yp[2]*yp[2] + zp[2]*zp[2] < 2.*FTINY*FTINY) {
                /* Special case for X' along Z-axis */
                theta = -atan2(yp[0], yp[1]);
                sprintf(xf, " -ry %f -rz %f",
                                xp[2] < 0.0 ? 90.0 : -90.0,
                                theta*(180./PI));
                return(4);
        }
        n = 0;
        theta = atan2(yp[2], zp[2]);
        if (!FEQ(theta,0.0)) {
                sprintf(xf, " -rx %f", theta*(180./PI));
                while (*xf) ++xf;
                n += 2;
        }
        theta = asin(-xp[2]);
        if (!FEQ(theta,0.0)) {
                sprintf(xf, " -ry %f", theta*(180./PI));
                while (*xf) ++xf;
                n += 2;
        }
        theta = atan2(xp[1], xp[0]);
        if (!FEQ(theta,0.0)) {
                sprintf(xf, " -rz %f", theta*(180./PI));
                /* while (*xf) ++xf; */
                n += 2;
        }
        return(n);
}
Revision:	2.15
Committed:	Fri Jan 25 02:11:13 2008 UTC (16 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad4R1, rad4R0, rad3R9
Changes since 2.14:	+9 -1 lines
Log Message:	Fixed bug in rotation computation when X' is aligned with Z-axis
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.15	static const char RCSid[] = "$Id: replmarks.c,v 2.14 2005/12/28 18:35:42 greg Exp $";
3	greg	1.1	#endif
4			/*
5			* Replace markers in Radiance scene description with objects or instances.
6			*
7			* Created: 17 Feb 1991 Greg Ward
8			*/
9
10	greg	2.5	#include <stdlib.h>
11	greg	1.1	#include <ctype.h>
12			#include <math.h>
13	schorsch	2.7	#include <stdio.h>
14	greg	1.1
15	schorsch	2.7	#include "platform.h"
16	schorsch	2.9	#include "rtio.h"
17	schorsch	2.8	#include "rtprocess.h"
18	greg	1.1	#include "fvect.h"
19
20			#ifdef M_PI
21	gregl	2.4	#define PI ((double)M_PI)
22	greg	1.1	#else
23			#define PI 3.14159265358979323846
24			#endif
25
26	greg	1.2	#define FEQ(a,b) ((a)-(b) <= 1e-7 && (b)-(a) <= 1e-7)
27
28	greg	1.1	#define MAXVERT 6 /* maximum number of vertices for markers */
29	greg	2.13	#define MAXMARK 128 /* maximum number of markers */
30	greg	1.1
31	greg	2.11	#define USE_XFORM 1 /* use !xform inline command */
32			#define USE_INSTANCE 2 /* use instance primitive */
33			#define USE_MESH 3 /* use mesh primitive */
34
35	greg	1.1	typedef struct {
36			short beg, end; /* beginning and ending vertex */
37			float len2; /* length squared */
38			} EDGE; /* a marker edge */
39
40	greg	2.2	struct mrkr {
41			char modout; / output modifier */
42			double mscale; /* scale by this to get unit */
43			char modin; / input modifier indicating marker */
44			char objname; / output object file or octree */
45	greg	2.11	int usetype; /* one of USE_* above */
46	greg	2.13	} marker[MAXMARK+1]; /* array of markers */
47	greg	2.2	int nmarkers = 0; /* number of markers */
48	greg	1.1
49	greg	2.2	int expand; /* expand commands? */
50	greg	1.1
51			char *progname;
52
53	schorsch	2.9	static void convert(char name, FILE fin);
54			static void cvcomm(char fname, FILE fin);
55			static void cvobject(char fname, FILE fin);
56			static void replace(char fname, struct mrkr m, char mark, FILE fin);
57			static int edgecmp(const void e1, const void e2);
58			static int buildxf(char xf, double markscale, FILE fin);
59			static int addrot(char *xf, FVECT xp, FVECT yp, FVECT zp);
60	greg	1.1
61	schorsch	2.9
62			int
63			main(
64			int argc,
65			char *argv[]
66			)
67	greg	1.1	{
68			FILE *fp;
69			int i, j;
70
71			progname = argv[0];
72	greg	2.2	i = 1;
73			while (i < argc && argv[i][0] == '-') {
74			do {
75			switch (argv[i][1]) {
76			case 'i':
77	greg	2.11	marker[nmarkers].usetype = USE_INSTANCE;
78			marker[nmarkers].objname = argv[++i];
79			break;
80			case 'I':
81			marker[nmarkers].usetype = USE_MESH;
82	greg	2.2	marker[nmarkers].objname = argv[++i];
83			break;
84			case 'x':
85	greg	2.11	marker[nmarkers].usetype = USE_XFORM;
86	greg	2.2	marker[nmarkers].objname = argv[++i];
87			break;
88			case 'e':
89			expand = 1;
90			break;
91			case 'm':
92			marker[nmarkers].modout = argv[++i];
93			break;
94			case 's':
95			marker[nmarkers].mscale = atof(argv[++i]);
96			break;
97			default:
98			goto userr;
99			}
100			if (++i >= argc)
101			goto userr;
102			} while (argv[i][0] == '-');
103			if (marker[nmarkers].objname == NULL)
104			goto userr;
105	greg	2.13	if (nmarkers >= MAXMARK) {
106			fprintf(stderr, "%s: too many markers\n", progname);
107			return 1;
108			}
109	greg	2.2	marker[nmarkers++].modin = argv[i++];
110			marker[nmarkers].mscale = marker[nmarkers-1].mscale;
111			}
112			if (nmarkers == 0)
113	greg	1.1	goto userr;
114			/* simple header */
115			putchar('#');
116			for (j = 0; j < i; j++) {
117			putchar(' ');
118			fputs(argv[j], stdout);
119			}
120			putchar('\n');
121			if (i == argc)
122			convert("<stdin>", stdin);
123			else
124			for ( ; i < argc; i++) {
125			if ((fp = fopen(argv[i], "r")) == NULL) {
126			perror(argv[i]);
127			exit(1);
128			}
129			convert(argv[i], fp);
130			fclose(fp);
131			}
132	schorsch	2.9	return 0;
133	greg	1.1	userr:
134			fprintf(stderr,
135	greg	2.11	"Usage: %s [-e][-s size][-m modout] {-x objfile\|-i octree\|-I mesh} modname .. [file ..]\n",
136	greg	1.1	progname);
137	schorsch	2.9	return 1;
138	greg	1.1	}
139
140
141	schorsch	2.9	void
142			convert( /* replace marks in a stream */
143			char *name,
144			register FILE *fin
145			)
146	greg	1.1	{
147			register int c;
148
149			while ((c = getc(fin)) != EOF) {
150			if (isspace(c)) /* blank */
151			continue;
152			if (c == '#') { /* comment */
153			putchar(c);
154			do {
155			if ((c = getc(fin)) == EOF)
156			return;
157			putchar(c);
158			} while (c != '\n');
159			} else if (c == '!') { /* command */
160			ungetc(c, fin);
161			cvcomm(name, fin);
162			} else { /* object */
163			ungetc(c, fin);
164			cvobject(name, fin);
165			}
166			}
167			}
168
169
170	schorsch	2.9	void
171			cvcomm( /* convert a command */
172			char *fname,
173			FILE *fin
174			)
175	greg	1.1	{
176	schorsch	2.8	FILE *pin;
177	greg	1.1	char buf[512], *fgetline();
178
179			fgetline(buf, sizeof(buf), fin);
180			if (expand) {
181			if ((pin = popen(buf+1, "r")) == NULL) {
182			fprintf(stderr,
183			"%s: (%s): cannot execute \"%s\"\n",
184			progname, fname, buf);
185			exit(1);
186			}
187			convert(buf, pin);
188			pclose(pin);
189			} else
190			printf("\n%s\n", buf);
191			}
192
193
194	schorsch	2.9	void
195			cvobject( /* convert an object */
196			char *fname,
197			FILE *fin
198			)
199	greg	1.1	{
200	greg	2.6	extern char *fgetword();
201	greg	1.1	char buf[128], typ[16], nam[128];
202	greg	2.2	int i, n;
203			register int j;
204	greg	1.1
205	greg	2.14	if (fgetword(buf, sizeof(buf), fin) == NULL \|\|
206			fgetword(typ, sizeof(typ), fin) == NULL \|\|
207			fgetword(nam, sizeof(nam), fin) == NULL)
208	greg	1.1	goto readerr;
209	greg	2.2	if (!strcmp(typ, "polygon"))
210			for (j = 0; j < nmarkers; j++)
211			if (!strcmp(buf, marker[j].modin)) {
212			replace(fname, &marker[j], nam, fin);
213			return;
214			}
215	greg	2.14	putchar('\n'); fputword(buf, stdout);
216			printf(" %s ", typ);
217			fputword(nam, stdout); putchar('\n');
218	greg	1.1	if (!strcmp(typ, "alias")) { /* alias special case */
219	greg	2.14	if (fgetword(buf, sizeof(buf), fin) == NULL)
220	greg	1.1	goto readerr;
221	greg	2.14	putchar('\t'); fputword(buf, stdout); putchar('\n');
222	greg	1.1	return;
223			}
224			for (i = 0; i < 3; i++) { /* pass along arguments */
225			if (fscanf(fin, "%d", &n) != 1)
226			goto readerr;
227			printf("%d", n);
228			for (j = 0; j < n; j++) {
229	greg	2.5	if (fgetword(buf, sizeof(buf), fin) == NULL)
230	greg	1.1	goto readerr;
231			if (j%3 == 0)
232			putchar('\n');
233	greg	2.5	putchar('\t');
234			fputword(buf, stdout);
235	greg	1.1	}
236			putchar('\n');
237			}
238			return;
239			readerr:
240			fprintf(stderr, "%s: (%s): read error for %s \"%s\"\n",
241			progname, fname, typ, nam);
242			}
243
244
245	schorsch	2.9	void
246			replace( /* replace marker */
247			char *fname,
248			register struct mrkr *m,
249			char *mark,
250			FILE *fin
251			)
252	greg	1.1	{
253			int n;
254			char buf[256];
255
256	greg	2.5	buf[0] = '\0'; /* bug fix thanks to schorsch */
257	greg	2.11	if (m->usetype == USE_XFORM) {
258	greg	2.10	sprintf(buf, "xform -n %s", mark);
259	greg	2.2	if (m->modout != NULL)
260			sprintf(buf+strlen(buf), " -m %s", m->modout);
261			if (buildxf(buf+strlen(buf), m->mscale, fin) < 0)
262	greg	1.1	goto badxf;
263	greg	2.2	sprintf(buf+strlen(buf), " %s", m->objname);
264	greg	1.1	if (expand) {
265			fflush(stdout);
266			system(buf);
267			} else
268			printf("\n!%s\n", buf);
269			} else {
270	greg	2.2	if ((n = buildxf(buf, m->mscale, fin)) < 0)
271	greg	1.1	goto badxf;
272	greg	2.11	printf("\n%s %s %s\n",
273			m->modout==NULL?"void":m->modout,
274			m->usetype==USE_INSTANCE?"instance":"mesh",
275			mark);
276	greg	2.2	printf("%d %s%s\n0\n0\n", n+1, m->objname, buf);
277	greg	1.1	}
278			return;
279			badxf:
280			fprintf(stderr, "%s: (%s): bad arguments for marker \"%s\"\n",
281			progname, fname, mark);
282			exit(1);
283			}
284
285
286	schorsch	2.9	int
287			edgecmp( /* compare two edges, descending order */
288			const void *e1,
289			const void *e2
290			)
291	greg	1.1	{
292	schorsch	2.9	if (((EDGE)e1)->len2 > ((EDGE)e2)->len2)
293	greg	1.1	return(-1);
294	schorsch	2.9	if (((EDGE)e1)->len2 < ((EDGE)e2)->len2)
295	greg	1.1	return(1);
296			return(0);
297			}
298
299
300			int
301	schorsch	2.9	buildxf( /* build transform for marker */
302			register char *xf,
303			double markscale,
304			FILE *fin
305			)
306	greg	1.1	{
307			static FVECT vlist[MAXVERT];
308			static EDGE elist[MAXVERT];
309			FVECT xvec, yvec, zvec;
310			double xlen;
311			int n;
312			register int i;
313			/*
314			* Read and sort vectors: longest is hypotenuse,
315			* second longest is x' axis,
316			* third longest is y' axis (approximate),
317			* other vectors are ignored.
318			* It is an error if the x' and y' axes do
319			* not share a common vertex (their origin).
320			*/
321			if (fscanf(fin, "%d %d %d", &n) != 1)
322			return(-1);
323			if (n%3 != 0)
324			return(-1);
325			n /= 3;
326			if (n < 3 \|\| n > MAXVERT)
327			return(-1);
328			/* sort edges in descending order */
329			for (i = 0; i < n; i++) {
330			if (fscanf(fin, "%lf %lf %lf", &vlist[i][0],
331			&vlist[i][1], &vlist[i][2]) != 3)
332			return(-1);
333			if (i) {
334			elist[i].beg = i-1;
335			elist[i].end = i;
336			elist[i].len2 = dist2(vlist[i-1],vlist[i]);
337			}
338			}
339			elist[0].beg = n-1;
340			elist[0].end = 0;
341			elist[0].len2 = dist2(vlist[n-1],vlist[0]);
342			qsort(elist, n, sizeof(EDGE), edgecmp);
343			/* find x' and y' */
344			if (elist[1].end == elist[2].beg \|\| elist[1].end == elist[2].end) {
345			i = elist[1].beg;
346			elist[1].beg = elist[1].end;
347			elist[1].end = i;
348			}
349			if (elist[2].end == elist[1].beg) {
350			i = elist[2].beg;
351			elist[2].beg = elist[2].end;
352			elist[2].end = i;
353			}
354			if (elist[1].beg != elist[2].beg)
355			return(-1); /* x' and y' not connected! */
356			for (i = 0; i < 3; i++) {
357			xvec[i] = vlist[elist[1].end][i] - vlist[elist[1].beg][i];
358			yvec[i] = vlist[elist[2].end][i] - vlist[elist[2].beg][i];
359			}
360			if ((xlen = normalize(xvec)) == 0.0)
361			return(-1);
362			fcross(zvec, xvec, yvec);
363			if (normalize(zvec) == 0.0)
364			return(-1);
365			fcross(yvec, zvec, xvec);
366			n = 0; /* start transformation... */
367			if (markscale > 0.0) { /* add scale factor */
368			sprintf(xf, " -s %f", xlen*markscale);
369			n += 2;
370	greg	2.5	while (*xf) ++xf;
371	greg	1.1	}
372			/* add rotation */
373			n += addrot(xf, xvec, yvec, zvec);
374	greg	2.5	while (*xf) ++xf;
375	greg	1.1	/* add translation */
376			n += 4;
377			sprintf(xf, " -t %f %f %f", vlist[elist[1].beg][0],
378			vlist[elist[1].beg][1], vlist[elist[1].beg][2]);
379			return(n); /* all done */
380			}
381
382
383	schorsch	2.9	int
384			addrot( /* compute rotation (x,y,z) => (xp,yp,zp) */
385			register char *xf,
386			FVECT xp,
387			FVECT yp,
388			FVECT zp
389			)
390	greg	1.1	{
391	greg	1.2	int n;
392			double theta;
393	greg	1.1
394	greg	2.15	if (yp[2]yp[2] + zp[2]zp[2] < 2.FTINYFTINY) {
395			/* Special case for X' along Z-axis */
396			theta = -atan2(yp[0], yp[1]);
397			sprintf(xf, " -ry %f -rz %f",
398			xp[2] < 0.0 ? 90.0 : -90.0,
399			theta*(180./PI));
400			return(4);
401			}
402	greg	1.2	n = 0;
403			theta = atan2(yp[2], zp[2]);
404			if (!FEQ(theta,0.0)) {
405			sprintf(xf, " -rx %f", theta*(180./PI));
406	greg	2.5	while (*xf) ++xf;
407	greg	1.2	n += 2;
408			}
409			theta = asin(-xp[2]);
410			if (!FEQ(theta,0.0)) {
411			sprintf(xf, " -ry %f", theta*(180./PI));
412	greg	2.5	while (*xf) ++xf;
413	greg	1.2	n += 2;
414			}
415			theta = atan2(xp[1], xp[0]);
416			if (!FEQ(theta,0.0)) {
417			sprintf(xf, " -rz %f", theta*(180./PI));
418	greg	2.5	/* while (xf) ++xf; /
419	greg	1.2	n += 2;
420			}
421			return(n);
422	greg	1.1	}