src/gen/replmarks.c

#ifndef lint
static const char RCSid[] = "$Id: replmarks.c,v 2.17 2016/02/02 18:02:32 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 "paths.h"
#include "fvect.h"

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

#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 (!FABSEQ(theta,0.0)) {
                sprintf(xf, " -rx %f", theta*(180./PI));
                while (*xf) ++xf;
                n += 2;
        }
        theta = Asin(-xp[2]);
        if (!FABSEQ(theta,0.0)) {
                sprintf(xf, " -ry %f", theta*(180./PI));
                while (*xf) ++xf;
                n += 2;
        }
        theta = atan2(xp[1], xp[0]);
        if (!FABSEQ(theta,0.0)) {
                sprintf(xf, " -rz %f", theta*(180./PI));
                /* while (*xf) ++xf; */
                n += 2;
        }
        return(n);
}
Revision:	2.18
Committed:	Fri Feb 12 00:53:56 2021 UTC (4 years, 8 months ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad5R4
Changes since 2.17:	+4 -6 lines
Log Message:	refactor: Created comparison macros for RREAL and FVECT types
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.18	static const char RCSid[] = "$Id: replmarks.c,v 2.17 2016/02/02 18:02:32 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	greg	2.17	#include "paths.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			#define MAXVERT 6 /* maximum number of vertices for markers */
27	greg	2.13	#define MAXMARK 128 /* maximum number of markers */
28	greg	1.1
29	greg	2.11	#define USE_XFORM 1 /* use !xform inline command */
30			#define USE_INSTANCE 2 /* use instance primitive */
31			#define USE_MESH 3 /* use mesh primitive */
32
33	greg	1.1	typedef struct {
34			short beg, end; /* beginning and ending vertex */
35			float len2; /* length squared */
36			} EDGE; /* a marker edge */
37
38	greg	2.2	struct mrkr {
39			char modout; / output modifier */
40			double mscale; /* scale by this to get unit */
41			char modin; / input modifier indicating marker */
42			char objname; / output object file or octree */
43	greg	2.11	int usetype; /* one of USE_* above */
44	greg	2.13	} marker[MAXMARK+1]; /* array of markers */
45	greg	2.2	int nmarkers = 0; /* number of markers */
46	greg	1.1
47	greg	2.2	int expand; /* expand commands? */
48	greg	1.1
49			char *progname;
50
51	schorsch	2.9	static void convert(char name, FILE fin);
52			static void cvcomm(char fname, FILE fin);
53			static void cvobject(char fname, FILE fin);
54			static void replace(char fname, struct mrkr m, char mark, FILE fin);
55			static int edgecmp(const void e1, const void e2);
56			static int buildxf(char xf, double markscale, FILE fin);
57			static int addrot(char *xf, FVECT xp, FVECT yp, FVECT zp);
58	greg	1.1
59	schorsch	2.9
60			int
61			main(
62			int argc,
63			char *argv[]
64			)
65	greg	1.1	{
66			FILE *fp;
67			int i, j;
68
69			progname = argv[0];
70	greg	2.2	i = 1;
71			while (i < argc && argv[i][0] == '-') {
72			do {
73			switch (argv[i][1]) {
74			case 'i':
75	greg	2.11	marker[nmarkers].usetype = USE_INSTANCE;
76			marker[nmarkers].objname = argv[++i];
77			break;
78			case 'I':
79			marker[nmarkers].usetype = USE_MESH;
80	greg	2.2	marker[nmarkers].objname = argv[++i];
81			break;
82			case 'x':
83	greg	2.11	marker[nmarkers].usetype = USE_XFORM;
84	greg	2.2	marker[nmarkers].objname = argv[++i];
85			break;
86			case 'e':
87			expand = 1;
88			break;
89			case 'm':
90			marker[nmarkers].modout = argv[++i];
91			break;
92			case 's':
93			marker[nmarkers].mscale = atof(argv[++i]);
94			break;
95			default:
96			goto userr;
97			}
98			if (++i >= argc)
99			goto userr;
100			} while (argv[i][0] == '-');
101			if (marker[nmarkers].objname == NULL)
102			goto userr;
103	greg	2.13	if (nmarkers >= MAXMARK) {
104			fprintf(stderr, "%s: too many markers\n", progname);
105			return 1;
106			}
107	greg	2.2	marker[nmarkers++].modin = argv[i++];
108			marker[nmarkers].mscale = marker[nmarkers-1].mscale;
109			}
110			if (nmarkers == 0)
111	greg	1.1	goto userr;
112			/* simple header */
113			putchar('#');
114			for (j = 0; j < i; j++) {
115			putchar(' ');
116			fputs(argv[j], stdout);
117			}
118			putchar('\n');
119			if (i == argc)
120			convert("<stdin>", stdin);
121			else
122			for ( ; i < argc; i++) {
123			if ((fp = fopen(argv[i], "r")) == NULL) {
124			perror(argv[i]);
125			exit(1);
126			}
127			convert(argv[i], fp);
128			fclose(fp);
129			}
130	schorsch	2.9	return 0;
131	greg	1.1	userr:
132			fprintf(stderr,
133	greg	2.11	"Usage: %s [-e][-s size][-m modout] {-x objfile\|-i octree\|-I mesh} modname .. [file ..]\n",
134	greg	1.1	progname);
135	schorsch	2.9	return 1;
136	greg	1.1	}
137
138
139	schorsch	2.9	void
140			convert( /* replace marks in a stream */
141			char *name,
142			register FILE *fin
143			)
144	greg	1.1	{
145			register int c;
146
147			while ((c = getc(fin)) != EOF) {
148			if (isspace(c)) /* blank */
149			continue;
150			if (c == '#') { /* comment */
151			putchar(c);
152			do {
153			if ((c = getc(fin)) == EOF)
154			return;
155			putchar(c);
156			} while (c != '\n');
157			} else if (c == '!') { /* command */
158			ungetc(c, fin);
159			cvcomm(name, fin);
160			} else { /* object */
161			ungetc(c, fin);
162			cvobject(name, fin);
163			}
164			}
165			}
166
167
168	schorsch	2.9	void
169			cvcomm( /* convert a command */
170			char *fname,
171			FILE *fin
172			)
173	greg	1.1	{
174	schorsch	2.8	FILE *pin;
175	greg	1.1	char buf[512], *fgetline();
176
177			fgetline(buf, sizeof(buf), fin);
178			if (expand) {
179			if ((pin = popen(buf+1, "r")) == NULL) {
180			fprintf(stderr,
181			"%s: (%s): cannot execute \"%s\"\n",
182			progname, fname, buf);
183			exit(1);
184			}
185			convert(buf, pin);
186			pclose(pin);
187			} else
188			printf("\n%s\n", buf);
189			}
190
191
192	schorsch	2.9	void
193			cvobject( /* convert an object */
194			char *fname,
195			FILE *fin
196			)
197	greg	1.1	{
198	greg	2.6	extern char *fgetword();
199	greg	1.1	char buf[128], typ[16], nam[128];
200	greg	2.2	int i, n;
201			register int j;
202	greg	1.1
203	greg	2.14	if (fgetword(buf, sizeof(buf), fin) == NULL \|\|
204			fgetword(typ, sizeof(typ), fin) == NULL \|\|
205			fgetword(nam, sizeof(nam), fin) == NULL)
206	greg	1.1	goto readerr;
207	greg	2.2	if (!strcmp(typ, "polygon"))
208			for (j = 0; j < nmarkers; j++)
209			if (!strcmp(buf, marker[j].modin)) {
210			replace(fname, &marker[j], nam, fin);
211			return;
212			}
213	greg	2.14	putchar('\n'); fputword(buf, stdout);
214			printf(" %s ", typ);
215			fputword(nam, stdout); putchar('\n');
216	greg	1.1	if (!strcmp(typ, "alias")) { /* alias special case */
217	greg	2.14	if (fgetword(buf, sizeof(buf), fin) == NULL)
218	greg	1.1	goto readerr;
219	greg	2.14	putchar('\t'); fputword(buf, stdout); putchar('\n');
220	greg	1.1	return;
221			}
222			for (i = 0; i < 3; i++) { /* pass along arguments */
223			if (fscanf(fin, "%d", &n) != 1)
224			goto readerr;
225			printf("%d", n);
226			for (j = 0; j < n; j++) {
227	greg	2.5	if (fgetword(buf, sizeof(buf), fin) == NULL)
228	greg	1.1	goto readerr;
229			if (j%3 == 0)
230			putchar('\n');
231	greg	2.5	putchar('\t');
232			fputword(buf, stdout);
233	greg	1.1	}
234			putchar('\n');
235			}
236			return;
237			readerr:
238			fprintf(stderr, "%s: (%s): read error for %s \"%s\"\n",
239			progname, fname, typ, nam);
240			}
241
242
243	schorsch	2.9	void
244			replace( /* replace marker */
245			char *fname,
246			register struct mrkr *m,
247			char *mark,
248			FILE *fin
249			)
250	greg	1.1	{
251			int n;
252			char buf[256];
253
254	greg	2.5	buf[0] = '\0'; /* bug fix thanks to schorsch */
255	greg	2.11	if (m->usetype == USE_XFORM) {
256	greg	2.10	sprintf(buf, "xform -n %s", mark);
257	greg	2.2	if (m->modout != NULL)
258			sprintf(buf+strlen(buf), " -m %s", m->modout);
259			if (buildxf(buf+strlen(buf), m->mscale, fin) < 0)
260	greg	1.1	goto badxf;
261	greg	2.2	sprintf(buf+strlen(buf), " %s", m->objname);
262	greg	1.1	if (expand) {
263			fflush(stdout);
264			system(buf);
265			} else
266			printf("\n!%s\n", buf);
267			} else {
268	greg	2.2	if ((n = buildxf(buf, m->mscale, fin)) < 0)
269	greg	1.1	goto badxf;
270	greg	2.11	printf("\n%s %s %s\n",
271			m->modout==NULL?"void":m->modout,
272			m->usetype==USE_INSTANCE?"instance":"mesh",
273			mark);
274	greg	2.2	printf("%d %s%s\n0\n0\n", n+1, m->objname, buf);
275	greg	1.1	}
276			return;
277			badxf:
278			fprintf(stderr, "%s: (%s): bad arguments for marker \"%s\"\n",
279			progname, fname, mark);
280			exit(1);
281			}
282
283
284	schorsch	2.9	int
285			edgecmp( /* compare two edges, descending order */
286			const void *e1,
287			const void *e2
288			)
289	greg	1.1	{
290	schorsch	2.9	if (((EDGE)e1)->len2 > ((EDGE)e2)->len2)
291	greg	1.1	return(-1);
292	schorsch	2.9	if (((EDGE)e1)->len2 < ((EDGE)e2)->len2)
293	greg	1.1	return(1);
294			return(0);
295			}
296
297
298			int
299	schorsch	2.9	buildxf( /* build transform for marker */
300			register char *xf,
301			double markscale,
302			FILE *fin
303			)
304	greg	1.1	{
305			static FVECT vlist[MAXVERT];
306			static EDGE elist[MAXVERT];
307			FVECT xvec, yvec, zvec;
308			double xlen;
309			int n;
310			register int i;
311			/*
312			* Read and sort vectors: longest is hypotenuse,
313			* second longest is x' axis,
314			* third longest is y' axis (approximate),
315			* other vectors are ignored.
316			* It is an error if the x' and y' axes do
317			* not share a common vertex (their origin).
318			*/
319			if (fscanf(fin, "%d %d %d", &n) != 1)
320			return(-1);
321			if (n%3 != 0)
322			return(-1);
323			n /= 3;
324			if (n < 3 \|\| n > MAXVERT)
325			return(-1);
326			/* sort edges in descending order */
327			for (i = 0; i < n; i++) {
328			if (fscanf(fin, "%lf %lf %lf", &vlist[i][0],
329			&vlist[i][1], &vlist[i][2]) != 3)
330			return(-1);
331			if (i) {
332			elist[i].beg = i-1;
333			elist[i].end = i;
334			elist[i].len2 = dist2(vlist[i-1],vlist[i]);
335			}
336			}
337			elist[0].beg = n-1;
338			elist[0].end = 0;
339			elist[0].len2 = dist2(vlist[n-1],vlist[0]);
340			qsort(elist, n, sizeof(EDGE), edgecmp);
341			/* find x' and y' */
342			if (elist[1].end == elist[2].beg \|\| elist[1].end == elist[2].end) {
343			i = elist[1].beg;
344			elist[1].beg = elist[1].end;
345			elist[1].end = i;
346			}
347			if (elist[2].end == elist[1].beg) {
348			i = elist[2].beg;
349			elist[2].beg = elist[2].end;
350			elist[2].end = i;
351			}
352			if (elist[1].beg != elist[2].beg)
353			return(-1); /* x' and y' not connected! */
354			for (i = 0; i < 3; i++) {
355			xvec[i] = vlist[elist[1].end][i] - vlist[elist[1].beg][i];
356			yvec[i] = vlist[elist[2].end][i] - vlist[elist[2].beg][i];
357			}
358			if ((xlen = normalize(xvec)) == 0.0)
359			return(-1);
360			fcross(zvec, xvec, yvec);
361			if (normalize(zvec) == 0.0)
362			return(-1);
363			fcross(yvec, zvec, xvec);
364			n = 0; /* start transformation... */
365			if (markscale > 0.0) { /* add scale factor */
366			sprintf(xf, " -s %f", xlen*markscale);
367			n += 2;
368	greg	2.5	while (*xf) ++xf;
369	greg	1.1	}
370			/* add rotation */
371			n += addrot(xf, xvec, yvec, zvec);
372	greg	2.5	while (*xf) ++xf;
373	greg	1.1	/* add translation */
374			n += 4;
375			sprintf(xf, " -t %f %f %f", vlist[elist[1].beg][0],
376			vlist[elist[1].beg][1], vlist[elist[1].beg][2]);
377			return(n); /* all done */
378			}
379
380
381	schorsch	2.9	int
382			addrot( /* compute rotation (x,y,z) => (xp,yp,zp) */
383			register char *xf,
384			FVECT xp,
385			FVECT yp,
386			FVECT zp
387			)
388	greg	1.1	{
389	greg	1.2	int n;
390			double theta;
391	greg	1.1
392	greg	2.15	if (yp[2]yp[2] + zp[2]zp[2] < 2.FTINYFTINY) {
393			/* Special case for X' along Z-axis */
394			theta = -atan2(yp[0], yp[1]);
395			sprintf(xf, " -ry %f -rz %f",
396			xp[2] < 0.0 ? 90.0 : -90.0,
397			theta*(180./PI));
398			return(4);
399			}
400	greg	1.2	n = 0;
401			theta = atan2(yp[2], zp[2]);
402	greg	2.18	if (!FABSEQ(theta,0.0)) {
403	greg	1.2	sprintf(xf, " -rx %f", theta*(180./PI));
404	greg	2.5	while (*xf) ++xf;
405	greg	1.2	n += 2;
406			}
407	greg	2.16	theta = Asin(-xp[2]);
408	greg	2.18	if (!FABSEQ(theta,0.0)) {
409	greg	1.2	sprintf(xf, " -ry %f", theta*(180./PI));
410	greg	2.5	while (*xf) ++xf;
411	greg	1.2	n += 2;
412			}
413			theta = atan2(xp[1], xp[0]);
414	greg	2.18	if (!FABSEQ(theta,0.0)) {
415	greg	1.2	sprintf(xf, " -rz %f", theta*(180./PI));
416	greg	2.5	/* while (xf) ++xf; /
417	greg	1.2	n += 2;
418			}
419			return(n);
420	greg	1.1	}