src/gen/gensurf.c

#ifndef lint
static const char RCSid[] = "$Id: gensurf.c,v 2.15 2004/03/26 21:30:12 schorsch Exp $";
#endif
/*
 *  gensurf.c - program to generate functional surfaces
 *
 *      Parametric functions x(s,t), y(s,t) and z(s,t)
 *  specify the surface, which is tesselated into an m by n
 *  array of paired triangles.
 *      The surface normal is defined by the right hand
 *  rule applied to (s,t).
 *
 *      4/3/87
 *
 *      4/16/02 Added conditional vertex output
 */

#include  "standard.h"

#include  "paths.h"
#include  "resolu.h"
#include  "rterror.h"
#include  "calcomp.h"

char  XNAME[] =         "X`SYS";                /* x function name */
char  YNAME[] =         "Y`SYS";                /* y function name */
char  ZNAME[] =         "Z`SYS";                /* z function name */

char  VNAME[] =         "valid";                /* valid vertex name */

#define  ABS(x)         ((x)>=0 ? (x) : -(x))

#define  ZEROVECT(v)    (DOT(v,v) <= FTINY*FTINY)

#define  pvect(p)       printf(vformat, (p)[0], (p)[1], (p)[2])

char  vformat[] = "%15.9g %15.9g %15.9g\n";
char  tsargs[] = "4 surf_dx surf_dy surf_dz surf.cal\n";
char  texname[] = "Phong";

int  smooth = 0;                /* apply smoothing? */
int  objout = 0;                /* output .OBJ format? */

char  *modname, *surfname;

                                /* recorded data flags */
#define  HASBORDER      01
#define  TRIPLETS       02
                                /* a data structure */
struct {
        int     flags;                  /* data type */
        short   m, n;                   /* number of s and t values */
        RREAL   *data;                  /* the data itself, s major sort */
} datarec;                      /* our recorded data */

/* XXX this is redundant with rt/noise3.c, should go to a library */
double  l_hermite(), l_bezier(), l_bspline(), l_dataval();

typedef struct {
        int  valid;     /* point is valid (vertex number) */
        FVECT  p;       /* vertex position */
        FVECT  n;       /* average normal */
        RREAL  uv[2];   /* (u,v) position */
} POINT;


void loaddata(char *file, int m, int n, int pointsize);
double l_dataval(char *nam);
void putobjrow(POINT *rp, int n);
void putsquare(POINT *p0, POINT *p1, POINT *p2, POINT *p3);
void comprow(double s, POINT *row, int siz);
void compnorms(POINT *r0, POINT *r1, POINT *r2, int siz);
int norminterp(FVECT resmat[4], POINT *p0, POINT *p1, POINT *p2, POINT *p3);


int
main(argc, argv)
int  argc;
char  *argv[];
{
        POINT  *row0, *row1, *row2, *rp;
        int  i, j, m, n;
        char  stmp[256];

        varset("PI", ':', PI);
        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(argv[++i], NULL, 0);
                else if (!strcmp(argv[i], "-f"))
                        fcompile(argv[++i]);
                else if (!strcmp(argv[i], "-s"))
                        smooth++;
                else if (!strcmp(argv[i], "-o"))
                        objout++;
                else
                        goto userror;

        modname = argv[1];
        surfname = argv[2];
        m = atoi(argv[6]);
        n = atoi(argv[7]);
        if (m <= 0 || n <= 0)
                goto userror;
        if (!strcmp(argv[5], "-") || access(argv[5], 4) == 0) { /* file? */
                funset(ZNAME, 2, ':', l_dataval);
                if (!strcmp(argv[5],argv[3]) && !strcmp(argv[5],argv[4])) {
                        loaddata(argv[5], m, n, 3);
                        funset(XNAME, 2, ':', l_dataval);
                        funset(YNAME, 2, ':', l_dataval);
                } else {
                        loaddata(argv[5], m, n, 1);
                        sprintf(stmp, "%s(s,t)=%s;", XNAME, argv[3]);
                        scompile(stmp, NULL, 0);
                        sprintf(stmp, "%s(s,t)=%s;", YNAME, argv[4]);
                        scompile(stmp, NULL, 0);
                }
        } else {
                sprintf(stmp, "%s(s,t)=%s;", XNAME, argv[3]);
                scompile(stmp, NULL, 0);
                sprintf(stmp, "%s(s,t)=%s;", YNAME, argv[4]);
                scompile(stmp, NULL, 0);
                sprintf(stmp, "%s(s,t)=%s;", ZNAME, argv[5]);
                scompile(stmp, NULL, 0);
        }
        row0 = (POINT *)malloc((n+3)*sizeof(POINT));
        row1 = (POINT *)malloc((n+3)*sizeof(POINT));
        row2 = (POINT *)malloc((n+3)*sizeof(POINT));
        if (row0 == NULL || row1 == NULL || row2 == NULL) {
                fprintf(stderr, "%s: out of memory\n", argv[0]);
                quit(1);
        }
        row0++; row1++; row2++;
                                                /* print header */
        fputs("# ", stdout);
        printargs(argc, argv, stdout);
        eclock = 0;
                                                /* initialize */
        comprow(-1.0/m, row0, n);
        comprow(0.0, row1, n);
        comprow(1.0/m, row2, n);
        compnorms(row0, row1, row2, n);
        if (objout) {
                printf("\nusemtl %s\n\n", modname);
                putobjrow(row1, n);
        }
                                                /* for each row */
        for (i = 0; i < m; i++) {
                                                /* compute next row */
                rp = row0;
                row0 = row1;
                row1 = row2;
                row2 = rp;
                comprow((double)(i+2)/m, row2, n);
                compnorms(row0, row1, row2, n);
                if (objout)
                        putobjrow(row1, n);

                for (j = 0; j < n; j++) {
                        int  orient = (j & 1);
                                                        /* put polygons */
                        if (!(row0[j].valid && row1[j+1].valid))
                                orient = 1;
                        else if (!(row1[j].valid && row0[j+1].valid))
                                orient = 0;
                        if (orient)
                                putsquare(&row0[j], &row1[j],
                                                &row0[j+1], &row1[j+1]);
                        else
                                putsquare(&row1[j], &row1[j+1],
                                                &row0[j], &row0[j+1]);
                }
        }

        return 0;

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


void
loaddata(               /* load point data from file */
        char  *file,
        int  m,
        int  n,
        int  pointsize
)
{
        FILE  *fp;
        char  word[64];
        register int  size;
        register RREAL  *dp;

        datarec.flags = HASBORDER;              /* assume border values */
        datarec.m = m+1;
        datarec.n = n+1;
        size = datarec.m*datarec.n*pointsize;
        if (pointsize == 3)
                datarec.flags |= TRIPLETS;
        dp = (RREAL *)malloc(size*sizeof(RREAL));
        if ((datarec.data = dp) == NULL) {
                fputs("Out of memory\n", stderr);
                exit(1);
        }
        if (!strcmp(file, "-")) {
                file = "<stdin>";
                fp = stdin;
        } else if ((fp = fopen(file, "r")) == NULL) {
                fputs(file, stderr);
                fputs(": cannot open\n", stderr);
                exit(1);
        }
        while (size > 0 && fgetword(word, sizeof(word), fp) != NULL) {
                if (!isflt(word)) {
                        fprintf(stderr, "%s: garbled data value: %s\n",
                                        file, word);
                        exit(1);
                }
                *dp++ = atof(word);
                size--;
        }
        if (size == (m+n+1)*pointsize) {        /* no border after all */
                dp = (RREAL *)realloc((void *)datarec.data,
                                m*n*pointsize*sizeof(RREAL));
                if (dp != NULL)
                        datarec.data = dp;
                datarec.flags &= ~HASBORDER;
                datarec.m = m;
                datarec.n = n;
                size = 0;
        }
        if (datarec.m < 2 || datarec.n < 2 || size != 0 ||
                        fgetword(word, sizeof(word), fp) != NULL) {
                fputs(file, stderr);
                fputs(": bad number of data points\n", stderr);
                exit(1);
        }
        fclose(fp);
}


double
l_dataval(                              /* return recorded data value */
        char  *nam
)
{
        double  u, v;
        register int  i, j;
        register RREAL  *dp;
        double  d00, d01, d10, d11;
                                                /* compute coordinates */
        u = argument(1); v = argument(2);
        if (datarec.flags & HASBORDER) {
                i = u *= datarec.m-1;
                j = v *= datarec.n-1;
        } else {
                i = u = u*datarec.m - .5;
                j = v = v*datarec.n - .5;
        }
        if (i < 0) i = 0;
        else if (i > datarec.m-2) i = datarec.m-2;
        if (j < 0) j = 0;
        else if (j > datarec.n-2) j = datarec.n-2;
                                                /* compute value */
        if (datarec.flags & TRIPLETS) {
                dp = datarec.data + 3*(j*datarec.m + i);
                if (nam == ZNAME)
                        dp += 2;
                else if (nam == YNAME)
                        dp++;
                d00 = dp[0]; d01 = dp[3];
                dp += 3*datarec.m;
                d10 = dp[0]; d11 = dp[3];
        } else {
                dp = datarec.data + j*datarec.m + i;
                d00 = dp[0]; d01 = dp[1];
                dp += datarec.m;
                d10 = dp[0]; d11 = dp[1];
        }
                                                /* bilinear interpolation */
        return((j+1-v)*((i+1-u)*d00+(u-i)*d01)+(v-j)*((i+1-u)*d10+(u-i)*d11));
}


void
putobjrow(                      /* output vertex row to .OBJ */
        register POINT  *rp,
        int  n
)
{
        static int      nverts = 0;

        for ( ; n-- >= 0; rp++) {
                if (!rp->valid)
                        continue;
                fputs("v ", stdout);
                pvect(rp->p);
                if (smooth && !ZEROVECT(rp->n))
                        printf("\tvn %.9g %.9g %.9g\n",
                                        rp->n[0], rp->n[1], rp->n[2]);
                printf("\tvt %.9g %.9g\n", rp->uv[0], rp->uv[1]);
                rp->valid = ++nverts;
        }
}


void
putsquare(              /* put out a square */
        POINT *p0,
        POINT *p1,
        POINT *p2,
        POINT *p3
)
{
        static int  nout = 0;
        FVECT  norm[4];
        int  axis;
        FVECT  v1, v2, vc1, vc2;
        int  ok1, ok2;
                                        /* compute exact normals */
        ok1 = (p0->valid && p1->valid && p2->valid);
        if (ok1) {
                VSUB(v1, p1->p, p0->p);
                VSUB(v2, p2->p, p0->p);
                fcross(vc1, v1, v2);
                ok1 = (normalize(vc1) != 0.0);
        }
        ok2 = (p1->valid && p2->valid && p3->valid);
        if (ok2) {
                VSUB(v1, p2->p, p3->p);
                VSUB(v2, p1->p, p3->p);
                fcross(vc2, v1, v2);
                ok2 = (normalize(vc2) != 0.0);
        }
        if (!(ok1 | ok2))
                return;
        if (objout) {                   /* output .OBJ faces */
                int     p0n=0, p1n=0, p2n=0, p3n=0;
                if (smooth) {
                        if (!ZEROVECT(p0->n))
                                p0n = p0->valid;
                        if (!ZEROVECT(p1->n))
                                p1n = p1->valid;
                        if (!ZEROVECT(p2->n))
                                p2n = p2->valid;
                        if (!ZEROVECT(p3->n))
                                p3n = p3->valid;
                }
                if (ok1 & ok2 && fdot(vc1,vc2) >= 1.0-FTINY*FTINY) {
                        printf("f %d/%d/%d %d/%d/%d %d/%d/%d %d/%d/%d\n",
                                        p0->valid, p0->valid, p0n,
                                        p1->valid, p1->valid, p1n,
                                        p3->valid, p3->valid, p3n,
                                        p2->valid, p2->valid, p2n);
                        return;
                }
                if (ok1)
                        printf("f %d/%d/%d %d/%d/%d %d/%d/%d\n",
                                        p0->valid, p0->valid, p0n,
                                        p1->valid, p1->valid, p1n,
                                        p2->valid, p2->valid, p2n);
                if (ok2)
                        printf("f %d/%d/%d %d/%d/%d %d/%d/%d\n",
                                        p2->valid, p2->valid, p2n,
                                        p1->valid, p1->valid, p1n,
                                        p3->valid, p3->valid, p3n);
                return;
        }
                                        /* compute normal interpolation */
        axis = norminterp(norm, p0, p1, p2, p3);

                                        /* put out quadrilateral? */
        if (ok1 & ok2 && fdot(vc1,vc2) >= 1.0-FTINY*FTINY) {
                printf("\n%s ", modname);
                if (axis != -1) {
                        printf("texfunc %s\n", texname);
                        printf(tsargs);
                        printf("0\n13\t%d\n", axis);
                        pvect(norm[0]);
                        pvect(norm[1]);
                        pvect(norm[2]);
                        fvsum(v1, norm[3], vc1, -0.5);
                        fvsum(v1, v1, vc2, -0.5);
                        pvect(v1);
                        printf("\n%s ", texname);
                }
                printf("polygon %s.%d\n", surfname, ++nout);
                printf("0\n0\n12\n");
                pvect(p0->p);
                pvect(p1->p);
                pvect(p3->p);
                pvect(p2->p);
                return;
        }
                                        /* put out triangles? */
        if (ok1) {
                printf("\n%s ", modname);
                if (axis != -1) {
                        printf("texfunc %s\n", texname);
                        printf(tsargs);
                        printf("0\n13\t%d\n", axis);
                        pvect(norm[0]);
                        pvect(norm[1]);
                        pvect(norm[2]);
                        fvsum(v1, norm[3], vc1, -1.0);
                        pvect(v1);
                        printf("\n%s ", texname);
                }
                printf("polygon %s.%d\n", surfname, ++nout);
                printf("0\n0\n9\n");
                pvect(p0->p);
                pvect(p1->p);
                pvect(p2->p);
        }
        if (ok2) {
                printf("\n%s ", modname);
                if (axis != -1) {
                        printf("texfunc %s\n", texname);
                        printf(tsargs);
                        printf("0\n13\t%d\n", axis);
                        pvect(norm[0]);
                        pvect(norm[1]);
                        pvect(norm[2]);
                        fvsum(v2, norm[3], vc2, -1.0);
                        pvect(v2);
                        printf("\n%s ", texname);
                }
                printf("polygon %s.%d\n", surfname, ++nout);
                printf("0\n0\n9\n");
                pvect(p2->p);
                pvect(p1->p);
                pvect(p3->p);
        }
}


void
comprow(                        /* compute row of values */
        double  s,
        register POINT  *row,
        int  siz
)
{
        double  st[2];
        int  end;
        int  checkvalid;
        register int  i;
        
        if (smooth) {
                i = -1;                 /* compute one past each end */
                end = siz+1;
        } else {
                if (s < -FTINY || s > 1.0+FTINY)
                        return;
                i = 0;
                end = siz;
        }
        st[0] = s;
        checkvalid = (fundefined(VNAME) == 2);
        while (i <= end) {
                st[1] = (double)i/siz;
                if (checkvalid && funvalue(VNAME, 2, st) <= 0.0) {
                        row[i].valid = 0;
                        row[i].p[0] = row[i].p[1] = row[i].p[2] = 0.0;
                        row[i].uv[0] = row[i].uv[1] = 0.0;
                } else {
                        row[i].valid = 1;
                        row[i].p[0] = funvalue(XNAME, 2, st);
                        row[i].p[1] = funvalue(YNAME, 2, st);
                        row[i].p[2] = funvalue(ZNAME, 2, st);
                        row[i].uv[0] = st[0];
                        row[i].uv[1] = st[1];
                }
                i++;
        }
}


void
compnorms(              /* compute row of averaged normals */
        register POINT  *r0,
        register POINT  *r1,
        register POINT  *r2,
        int  siz
)
{
        FVECT  v1, v2;

        if (!smooth)                    /* not needed if no smoothing */
                return;
                                        /* compute row 1 normals */
        while (siz-- >= 0) {
                if (!r1[0].valid)
                        continue;
                if (!r0[0].valid) {
                        if (!r2[0].valid) {
                                r1[0].n[0] = r1[0].n[1] = r1[0].n[2] = 0.0;
                                continue;
                        }
                        fvsum(v1, r2[0].p, r1[0].p, -1.0);
                } else if (!r2[0].valid)
                        fvsum(v1, r1[0].p, r0[0].p, -1.0);
                else
                        fvsum(v1, r2[0].p, r0[0].p, -1.0);
                if (!r1[-1].valid) {
                        if (!r1[1].valid) {
                                r1[0].n[0] = r1[0].n[1] = r1[0].n[2] = 0.0;
                                continue;
                        }
                        fvsum(v2, r1[1].p, r1[0].p, -1.0);
                } else if (!r1[1].valid)
                        fvsum(v2, r1[0].p, r1[-1].p, -1.0);
                else
                        fvsum(v2, r1[1].p, r1[-1].p, -1.0);
                fcross(r1[0].n, v1, v2);
                normalize(r1[0].n);
                r0++; r1++; r2++;
        }
}


int
norminterp(     /* compute normal interpolation */
        register FVECT  resmat[4],
        POINT  *p0,
        POINT  *p1,
        POINT  *p2,
        POINT  *p3
)
{
#define u  ((ax+1)%3)
#define v  ((ax+2)%3)

        register int  ax;
        MAT4  eqnmat;
        FVECT  v1;
        register int  i, j;

        if (!smooth)                    /* no interpolation if no smoothing */
                return(-1);
                                        /* find dominant axis */
        VCOPY(v1, p0->n);
        fvsum(v1, v1, p1->n, 1.0);
        fvsum(v1, v1, p2->n, 1.0);
        fvsum(v1, v1, p3->n, 1.0);
        ax = ABS(v1[0]) > ABS(v1[1]) ? 0 : 1;
        ax = ABS(v1[ax]) > ABS(v1[2]) ? ax : 2;
                                        /* assign equation matrix */
        eqnmat[0][0] = p0->p[u]*p0->p[v];
        eqnmat[0][1] = p0->p[u];
        eqnmat[0][2] = p0->p[v];
        eqnmat[0][3] = 1.0;
        eqnmat[1][0] = p1->p[u]*p1->p[v];
        eqnmat[1][1] = p1->p[u];
        eqnmat[1][2] = p1->p[v];
        eqnmat[1][3] = 1.0;
        eqnmat[2][0] = p2->p[u]*p2->p[v];
        eqnmat[2][1] = p2->p[u];
        eqnmat[2][2] = p2->p[v];
        eqnmat[2][3] = 1.0;
        eqnmat[3][0] = p3->p[u]*p3->p[v];
        eqnmat[3][1] = p3->p[u];
        eqnmat[3][2] = p3->p[v];
        eqnmat[3][3] = 1.0;
                                        /* invert matrix (solve system) */
        if (!invmat4(eqnmat, eqnmat))
                return(-1);                     /* no solution */
                                        /* compute result matrix */
        for (j = 0; j < 4; j++)
                for (i = 0; i < 3; i++)
                        resmat[j][i] =  eqnmat[j][0]*p0->n[i] +
                                        eqnmat[j][1]*p1->n[i] +
                                        eqnmat[j][2]*p2->n[i] +
                                        eqnmat[j][3]*p3->n[i];
        return(ax);

#undef u
#undef v
}


double
l_hermite(char *nm)
{
        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(char *nm)
{
        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(char *nm)
{
        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:	2.16
Committed:	Sat Aug 21 11:54:06 2004 UTC (21 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad3R7P2, rad3R7P1, rad3R6, rad3R6P1, rad3R8
Changes since 2.15:	+5 -42 lines
Log Message:	Eliminated some redundant library calls
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.16	static const char RCSid[] = "$Id: gensurf.c,v 2.15 2004/03/26 21:30:12 schorsch Exp $";
3	greg	1.1	#endif
4	greg	1.2	/*
5	greg	1.1	* gensurf.c - program to generate functional surfaces
6			*
7			* Parametric functions x(s,t), y(s,t) and z(s,t)
8			* specify the surface, which is tesselated into an m by n
9			* array of paired triangles.
10			* The surface normal is defined by the right hand
11			* rule applied to (s,t).
12			*
13			* 4/3/87
14	greg	2.6	*
15			* 4/16/02 Added conditional vertex output
16	greg	1.1	*/
17
18	greg	2.14	#include "standard.h"
19	schorsch	2.15
20			#include "paths.h"
21	greg	2.16	#include "resolu.h"
22			#include "rterror.h"
23	schorsch	2.13	#include "calcomp.h"
24	greg	1.1
25	greg	2.6	char XNAME[] = "X`SYS"; /* x function name */
26			char YNAME[] = "Y`SYS"; /* y function name */
27			char ZNAME[] = "Z`SYS"; /* z function name */
28
29			char VNAME[] = "valid"; /* valid vertex name */
30	greg	1.1
31	greg	1.4	#define ABS(x) ((x)>=0 ? (x) : -(x))
32
33	greg	2.9	#define ZEROVECT(v) (DOT(v,v) <= FTINY*FTINY)
34
35	greg	1.3	#define pvect(p) printf(vformat, (p)[0], (p)[1], (p)[2])
36	greg	1.1
37			char vformat[] = "%15.9g %15.9g %15.9g\n";
38	greg	1.3	char tsargs[] = "4 surf_dx surf_dy surf_dz surf.cal\n";
39			char texname[] = "Phong";
40	greg	1.1
41	greg	1.3	int smooth = 0; /* apply smoothing? */
42	greg	2.7	int objout = 0; /* output .OBJ format? */
43	greg	1.1
44	greg	1.3	char modname, surfname;
45	greg	1.1
46	greg	2.2	/* recorded data flags */
47			#define HASBORDER 01
48			#define TRIPLETS 02
49			/* a data structure */
50			struct {
51			int flags; /* data type */
52			short m, n; /* number of s and t values */
53	schorsch	2.11	RREAL data; / the data itself, s major sort */
54	greg	2.2	} datarec; /* our recorded data */
55	greg	1.3
56	schorsch	2.13	/* XXX this is redundant with rt/noise3.c, should go to a library */
57	greg	2.2	double l_hermite(), l_bezier(), l_bspline(), l_dataval();
58
59	greg	1.3	typedef struct {
60	greg	2.7	int valid; /* point is valid (vertex number) */
61	greg	1.3	FVECT p; /* vertex position */
62			FVECT n; /* average normal */
63	schorsch	2.11	RREAL uv[2]; /* (u,v) position */
64	greg	1.3	} POINT;
65
66
67	schorsch	2.13	void loaddata(char *file, int m, int n, int pointsize);
68			double l_dataval(char *nam);
69			void putobjrow(POINT *rp, int n);
70			void putsquare(POINT p0, POINT p1, POINT p2, POINT p3);
71			void comprow(double s, POINT *row, int siz);
72			void compnorms(POINT r0, POINT r1, POINT *r2, int siz);
73			int norminterp(FVECT resmat[4], POINT p0, POINT p1, POINT p2, POINT p3);
74
75
76			int
77	greg	1.1	main(argc, argv)
78			int argc;
79			char *argv[];
80			{
81	greg	1.3	POINT row0, row1, row2, rp;
82	greg	1.1	int i, j, m, n;
83			char stmp[256];
84
85	greg	1.13	varset("PI", ':', PI);
86	greg	1.14	funset("hermite", 5, ':', l_hermite);
87			funset("bezier", 5, ':', l_bezier);
88			funset("bspline", 5, ':', l_bspline);
89	greg	1.1
90			if (argc < 8)
91			goto userror;
92
93			for (i = 8; i < argc; i++)
94			if (!strcmp(argv[i], "-e"))
95	greg	1.10	scompile(argv[++i], NULL, 0);
96	greg	1.1	else if (!strcmp(argv[i], "-f"))
97			fcompile(argv[++i]);
98	greg	1.3	else if (!strcmp(argv[i], "-s"))
99			smooth++;
100	greg	2.7	else if (!strcmp(argv[i], "-o"))
101			objout++;
102	greg	1.1	else
103			goto userror;
104
105	greg	1.3	modname = argv[1];
106			surfname = argv[2];
107	greg	1.1	m = atoi(argv[6]);
108			n = atoi(argv[7]);
109			if (m <= 0 \|\| n <= 0)
110			goto userror;
111	greg	2.2	if (!strcmp(argv[5], "-") \|\| access(argv[5], 4) == 0) { /* file? */
112			funset(ZNAME, 2, ':', l_dataval);
113			if (!strcmp(argv[5],argv[3]) && !strcmp(argv[5],argv[4])) {
114			loaddata(argv[5], m, n, 3);
115			funset(XNAME, 2, ':', l_dataval);
116			funset(YNAME, 2, ':', l_dataval);
117			} else {
118			loaddata(argv[5], m, n, 1);
119			sprintf(stmp, "%s(s,t)=%s;", XNAME, argv[3]);
120			scompile(stmp, NULL, 0);
121			sprintf(stmp, "%s(s,t)=%s;", YNAME, argv[4]);
122			scompile(stmp, NULL, 0);
123			}
124			} else {
125			sprintf(stmp, "%s(s,t)=%s;", XNAME, argv[3]);
126			scompile(stmp, NULL, 0);
127			sprintf(stmp, "%s(s,t)=%s;", YNAME, argv[4]);
128			scompile(stmp, NULL, 0);
129			sprintf(stmp, "%s(s,t)=%s;", ZNAME, argv[5]);
130			scompile(stmp, NULL, 0);
131			}
132	greg	1.4	row0 = (POINT )malloc((n+3)sizeof(POINT));
133			row1 = (POINT )malloc((n+3)sizeof(POINT));
134			row2 = (POINT )malloc((n+3)sizeof(POINT));
135	greg	1.3	if (row0 == NULL \|\| row1 == NULL \|\| row2 == NULL) {
136	greg	1.1	fprintf(stderr, "%s: out of memory\n", argv[0]);
137			quit(1);
138			}
139	greg	1.4	row0++; row1++; row2++;
140	greg	1.3	/* print header */
141	greg	2.16	fputs("# ", stdout);
142			printargs(argc, argv, stdout);
143	greg	1.9	eclock = 0;
144	greg	1.4	/* initialize */
145			comprow(-1.0/m, row0, n);
146	greg	1.3	comprow(0.0, row1, n);
147			comprow(1.0/m, row2, n);
148	greg	1.4	compnorms(row0, row1, row2, n);
149	greg	2.8	if (objout) {
150			printf("\nusemtl %s\n\n", modname);
151	greg	2.7	putobjrow(row1, n);
152	greg	2.8	}
153	greg	1.3	/* for each row */
154	greg	1.1	for (i = 0; i < m; i++) {
155			/* compute next row */
156	greg	1.3	rp = row0;
157	greg	1.1	row0 = row1;
158	greg	1.3	row1 = row2;
159			row2 = rp;
160	greg	1.4	comprow((double)(i+2)/m, row2, n);
161			compnorms(row0, row1, row2, n);
162	greg	2.7	if (objout)
163			putobjrow(row1, n);
164	greg	1.1
165			for (j = 0; j < n; j++) {
166	greg	2.6	int orient = (j & 1);
167	greg	1.3	/* put polygons */
168	greg	2.7	if (!(row0[j].valid && row1[j+1].valid))
169	greg	2.6	orient = 1;
170	greg	2.7	else if (!(row1[j].valid && row0[j+1].valid))
171	greg	2.6	orient = 0;
172			if (orient)
173	greg	1.3	putsquare(&row0[j], &row1[j],
174			&row0[j+1], &row1[j+1]);
175			else
176			putsquare(&row1[j], &row1[j+1],
177			&row0[j], &row0[j+1]);
178	greg	1.1	}
179			}
180
181	schorsch	2.13	return 0;
182	greg	1.1
183			userror:
184			fprintf(stderr, "Usage: %s material name ", argv[0]);
185	greg	1.3	fprintf(stderr, "x(s,t) y(s,t) z(s,t) m n [-s][-e expr][-f file]\n");
186	schorsch	2.13	return 1;
187	greg	2.2	}
188
189
190	schorsch	2.13	void
191			loaddata( /* load point data from file */
192			char *file,
193			int m,
194			int n,
195			int pointsize
196			)
197	greg	2.2	{
198			FILE *fp;
199			char word[64];
200			register int size;
201	schorsch	2.11	register RREAL *dp;
202	greg	2.2
203			datarec.flags = HASBORDER; /* assume border values */
204	greg	2.3	datarec.m = m+1;
205			datarec.n = n+1;
206			size = datarec.mdatarec.npointsize;
207	greg	2.2	if (pointsize == 3)
208			datarec.flags \|= TRIPLETS;
209	schorsch	2.11	dp = (RREAL )malloc(sizesizeof(RREAL));
210	greg	2.2	if ((datarec.data = dp) == NULL) {
211			fputs("Out of memory\n", stderr);
212			exit(1);
213			}
214			if (!strcmp(file, "-")) {
215			file = "<stdin>";
216			fp = stdin;
217			} else if ((fp = fopen(file, "r")) == NULL) {
218			fputs(file, stderr);
219			fputs(": cannot open\n", stderr);
220			exit(1);
221			}
222			while (size > 0 && fgetword(word, sizeof(word), fp) != NULL) {
223			if (!isflt(word)) {
224			fprintf(stderr, "%s: garbled data value: %s\n",
225			file, word);
226			exit(1);
227			}
228			*dp++ = atof(word);
229			size--;
230			}
231			if (size == (m+n+1)pointsize) { / no border after all */
232	schorsch	2.11	dp = (RREAL )realloc((void )datarec.data,
233			mnpointsize*sizeof(RREAL));
234	greg	2.2	if (dp != NULL)
235			datarec.data = dp;
236			datarec.flags &= ~HASBORDER;
237	greg	2.3	datarec.m = m;
238			datarec.n = n;
239	greg	2.2	size = 0;
240			}
241	greg	2.3	if (datarec.m < 2 \|\| datarec.n < 2 \|\| size != 0 \|\|
242			fgetword(word, sizeof(word), fp) != NULL) {
243	greg	2.2	fputs(file, stderr);
244			fputs(": bad number of data points\n", stderr);
245			exit(1);
246			}
247			fclose(fp);
248			}
249
250
251			double
252	schorsch	2.13	l_dataval( /* return recorded data value */
253			char *nam
254			)
255	greg	2.2	{
256			double u, v;
257			register int i, j;
258	schorsch	2.11	register RREAL *dp;
259	greg	2.2	double d00, d01, d10, d11;
260			/* compute coordinates */
261			u = argument(1); v = argument(2);
262			if (datarec.flags & HASBORDER) {
263	greg	2.3	i = u *= datarec.m-1;
264			j = v *= datarec.n-1;
265	greg	2.2	} else {
266	greg	2.3	i = u = u*datarec.m - .5;
267			j = v = v*datarec.n - .5;
268	greg	2.2	}
269			if (i < 0) i = 0;
270			else if (i > datarec.m-2) i = datarec.m-2;
271			if (j < 0) j = 0;
272			else if (j > datarec.n-2) j = datarec.n-2;
273			/* compute value */
274			if (datarec.flags & TRIPLETS) {
275	greg	2.3	dp = datarec.data + 3(jdatarec.m + i);
276			if (nam == ZNAME)
277			dp += 2;
278			else if (nam == YNAME)
279	greg	2.2	dp++;
280			d00 = dp[0]; d01 = dp[3];
281	greg	2.3	dp += 3*datarec.m;
282	greg	2.2	d10 = dp[0]; d11 = dp[3];
283			} else {
284	greg	2.3	dp = datarec.data + j*datarec.m + i;
285	greg	2.2	d00 = dp[0]; d01 = dp[1];
286	greg	2.3	dp += datarec.m;
287	greg	2.2	d10 = dp[0]; d11 = dp[1];
288			}
289			/* bilinear interpolation */
290			return((j+1-v)((i+1-u)d00+(u-i)d01)+(v-j)((i+1-u)d10+(u-i)d11));
291	greg	1.1	}
292
293
294	schorsch	2.13	void
295			putobjrow( /* output vertex row to .OBJ */
296			register POINT *rp,
297			int n
298			)
299	greg	2.7	{
300			static int nverts = 0;
301
302			for ( ; n-- >= 0; rp++) {
303			if (!rp->valid)
304			continue;
305			fputs("v ", stdout);
306	greg	2.9	pvect(rp->p);
307			if (smooth && !ZEROVECT(rp->n))
308	greg	2.7	printf("\tvn %.9g %.9g %.9g\n",
309			rp->n[0], rp->n[1], rp->n[2]);
310			printf("\tvt %.9g %.9g\n", rp->uv[0], rp->uv[1]);
311			rp->valid = ++nverts;
312			}
313			}
314
315
316	schorsch	2.13	void
317			putsquare( /* put out a square */
318			POINT *p0,
319			POINT *p1,
320			POINT *p2,
321			POINT *p3
322			)
323	greg	1.3	{
324			static int nout = 0;
325			FVECT norm[4];
326			int axis;
327			FVECT v1, v2, vc1, vc2;
328			int ok1, ok2;
329			/* compute exact normals */
330	greg	2.7	ok1 = (p0->valid && p1->valid && p2->valid);
331	greg	2.6	if (ok1) {
332	greg	2.9	VSUB(v1, p1->p, p0->p);
333			VSUB(v2, p2->p, p0->p);
334	greg	2.6	fcross(vc1, v1, v2);
335			ok1 = (normalize(vc1) != 0.0);
336			}
337	greg	2.7	ok2 = (p1->valid && p2->valid && p3->valid);
338	greg	2.6	if (ok2) {
339	greg	2.9	VSUB(v1, p2->p, p3->p);
340			VSUB(v2, p1->p, p3->p);
341	greg	2.6	fcross(vc2, v1, v2);
342			ok2 = (normalize(vc2) != 0.0);
343			}
344	greg	1.3	if (!(ok1 \| ok2))
345			return;
346	greg	2.7	if (objout) { /* output .OBJ faces */
347			int p0n=0, p1n=0, p2n=0, p3n=0;
348			if (smooth) {
349	greg	2.9	if (!ZEROVECT(p0->n))
350			p0n = p0->valid;
351			if (!ZEROVECT(p1->n))
352			p1n = p1->valid;
353			if (!ZEROVECT(p2->n))
354			p2n = p2->valid;
355			if (!ZEROVECT(p3->n))
356			p3n = p3->valid;
357	greg	2.7	}
358			if (ok1 & ok2 && fdot(vc1,vc2) >= 1.0-FTINY*FTINY) {
359			printf("f %d/%d/%d %d/%d/%d %d/%d/%d %d/%d/%d\n",
360	greg	2.9	p0->valid, p0->valid, p0n,
361			p1->valid, p1->valid, p1n,
362			p3->valid, p3->valid, p3n,
363			p2->valid, p2->valid, p2n);
364	greg	2.7	return;
365			}
366			if (ok1)
367			printf("f %d/%d/%d %d/%d/%d %d/%d/%d\n",
368	greg	2.9	p0->valid, p0->valid, p0n,
369			p1->valid, p1->valid, p1n,
370			p2->valid, p2->valid, p2n);
371	greg	2.7	if (ok2)
372			printf("f %d/%d/%d %d/%d/%d %d/%d/%d\n",
373	greg	2.9	p2->valid, p2->valid, p2n,
374			p1->valid, p1->valid, p1n,
375			p3->valid, p3->valid, p3n);
376	greg	2.7	return;
377			}
378	greg	1.3	/* compute normal interpolation */
379			axis = norminterp(norm, p0, p1, p2, p3);
380
381			/* put out quadrilateral? */
382			if (ok1 & ok2 && fdot(vc1,vc2) >= 1.0-FTINY*FTINY) {
383			printf("\n%s ", modname);
384			if (axis != -1) {
385			printf("texfunc %s\n", texname);
386			printf(tsargs);
387			printf("0\n13\t%d\n", axis);
388			pvect(norm[0]);
389			pvect(norm[1]);
390			pvect(norm[2]);
391			fvsum(v1, norm[3], vc1, -0.5);
392			fvsum(v1, v1, vc2, -0.5);
393			pvect(v1);
394			printf("\n%s ", texname);
395			}
396			printf("polygon %s.%d\n", surfname, ++nout);
397			printf("0\n0\n12\n");
398			pvect(p0->p);
399			pvect(p1->p);
400			pvect(p3->p);
401			pvect(p2->p);
402			return;
403			}
404			/* put out triangles? */
405			if (ok1) {
406			printf("\n%s ", modname);
407			if (axis != -1) {
408			printf("texfunc %s\n", texname);
409			printf(tsargs);
410			printf("0\n13\t%d\n", axis);
411			pvect(norm[0]);
412			pvect(norm[1]);
413			pvect(norm[2]);
414			fvsum(v1, norm[3], vc1, -1.0);
415			pvect(v1);
416			printf("\n%s ", texname);
417			}
418			printf("polygon %s.%d\n", surfname, ++nout);
419			printf("0\n0\n9\n");
420			pvect(p0->p);
421			pvect(p1->p);
422			pvect(p2->p);
423			}
424			if (ok2) {
425			printf("\n%s ", modname);
426			if (axis != -1) {
427			printf("texfunc %s\n", texname);
428			printf(tsargs);
429			printf("0\n13\t%d\n", axis);
430			pvect(norm[0]);
431			pvect(norm[1]);
432			pvect(norm[2]);
433			fvsum(v2, norm[3], vc2, -1.0);
434			pvect(v2);
435			printf("\n%s ", texname);
436			}
437			printf("polygon %s.%d\n", surfname, ++nout);
438			printf("0\n0\n9\n");
439			pvect(p2->p);
440			pvect(p1->p);
441			pvect(p3->p);
442			}
443			}
444
445
446	schorsch	2.13	void
447			comprow( /* compute row of values */
448			double s,
449			register POINT *row,
450			int siz
451			)
452	greg	1.1	{
453	greg	1.4	double st[2];
454	greg	1.8	int end;
455	greg	2.6	int checkvalid;
456	greg	1.4	register int i;
457	greg	1.8
458			if (smooth) {
459			i = -1; /* compute one past each end */
460			end = siz+1;
461			} else {
462			if (s < -FTINY \|\| s > 1.0+FTINY)
463			return;
464			i = 0;
465			end = siz;
466			}
467	greg	1.1	st[0] = s;
468	greg	2.6	checkvalid = (fundefined(VNAME) == 2);
469	greg	1.8	while (i <= end) {
470	greg	1.4	st[1] = (double)i/siz;
471	greg	2.6	if (checkvalid && funvalue(VNAME, 2, st) <= 0.0) {
472			row[i].valid = 0;
473			row[i].p[0] = row[i].p[1] = row[i].p[2] = 0.0;
474	greg	2.7	row[i].uv[0] = row[i].uv[1] = 0.0;
475	greg	2.6	} else {
476			row[i].valid = 1;
477			row[i].p[0] = funvalue(XNAME, 2, st);
478			row[i].p[1] = funvalue(YNAME, 2, st);
479			row[i].p[2] = funvalue(ZNAME, 2, st);
480	greg	2.7	row[i].uv[0] = st[0];
481			row[i].uv[1] = st[1];
482	greg	2.6	}
483	greg	1.8	i++;
484	greg	1.1	}
485	greg	1.3	}
486
487
488	schorsch	2.13	void
489			compnorms( /* compute row of averaged normals */
490			register POINT *r0,
491			register POINT *r1,
492			register POINT *r2,
493			int siz
494			)
495	greg	1.3	{
496	greg	1.11	FVECT v1, v2;
497	greg	1.3
498			if (!smooth) /* not needed if no smoothing */
499			return;
500	greg	2.6	/* compute row 1 normals */
501	greg	1.4	while (siz-- >= 0) {
502	greg	2.6	if (!r1[0].valid)
503			continue;
504			if (!r0[0].valid) {
505			if (!r2[0].valid) {
506			r1[0].n[0] = r1[0].n[1] = r1[0].n[2] = 0.0;
507			continue;
508			}
509			fvsum(v1, r2[0].p, r1[0].p, -1.0);
510			} else if (!r2[0].valid)
511			fvsum(v1, r1[0].p, r0[0].p, -1.0);
512			else
513			fvsum(v1, r2[0].p, r0[0].p, -1.0);
514			if (!r1[-1].valid) {
515			if (!r1[1].valid) {
516			r1[0].n[0] = r1[0].n[1] = r1[0].n[2] = 0.0;
517			continue;
518			}
519			fvsum(v2, r1[1].p, r1[0].p, -1.0);
520			} else if (!r1[1].valid)
521			fvsum(v2, r1[0].p, r1[-1].p, -1.0);
522			else
523			fvsum(v2, r1[1].p, r1[-1].p, -1.0);
524	greg	1.3	fcross(r1[0].n, v1, v2);
525			normalize(r1[0].n);
526			r0++; r1++; r2++;
527			}
528			}
529
530
531			int
532	schorsch	2.13	norminterp( /* compute normal interpolation */
533			register FVECT resmat[4],
534			POINT *p0,
535			POINT *p1,
536			POINT *p2,
537			POINT *p3
538			)
539	greg	1.3	{
540			#define u ((ax+1)%3)
541			#define v ((ax+2)%3)
542
543			register int ax;
544	greg	1.12	MAT4 eqnmat;
545	greg	1.3	FVECT v1;
546			register int i, j;
547
548			if (!smooth) /* no interpolation if no smoothing */
549			return(-1);
550			/* find dominant axis */
551			VCOPY(v1, p0->n);
552			fvsum(v1, v1, p1->n, 1.0);
553			fvsum(v1, v1, p2->n, 1.0);
554			fvsum(v1, v1, p3->n, 1.0);
555	greg	1.4	ax = ABS(v1[0]) > ABS(v1[1]) ? 0 : 1;
556			ax = ABS(v1[ax]) > ABS(v1[2]) ? ax : 2;
557	greg	1.3	/* assign equation matrix */
558			eqnmat[0][0] = p0->p[u]*p0->p[v];
559			eqnmat[0][1] = p0->p[u];
560			eqnmat[0][2] = p0->p[v];
561			eqnmat[0][3] = 1.0;
562			eqnmat[1][0] = p1->p[u]*p1->p[v];
563			eqnmat[1][1] = p1->p[u];
564			eqnmat[1][2] = p1->p[v];
565			eqnmat[1][3] = 1.0;
566			eqnmat[2][0] = p2->p[u]*p2->p[v];
567			eqnmat[2][1] = p2->p[u];
568			eqnmat[2][2] = p2->p[v];
569			eqnmat[2][3] = 1.0;
570			eqnmat[3][0] = p3->p[u]*p3->p[v];
571			eqnmat[3][1] = p3->p[u];
572			eqnmat[3][2] = p3->p[v];
573			eqnmat[3][3] = 1.0;
574			/* invert matrix (solve system) */
575	greg	2.5	if (!invmat4(eqnmat, eqnmat))
576	greg	1.3	return(-1); /* no solution */
577			/* compute result matrix */
578			for (j = 0; j < 4; j++)
579			for (i = 0; i < 3; i++)
580	greg	1.4	resmat[j][i] = eqnmat[j][0]*p0->n[i] +
581			eqnmat[j][1]*p1->n[i] +
582			eqnmat[j][2]*p2->n[i] +
583			eqnmat[j][3]*p3->n[i];
584	greg	1.3	return(ax);
585
586			#undef u
587			#undef v
588	greg	1.1	}
589
590
591			double
592	greg	2.12	l_hermite(char *nm)
593	greg	1.1	{
594			double t;
595
596			t = argument(5);
597			return( argument(1)((2.0t-3.0)tt+1.0) +
598			argument(2)(-2.0t+3.0)tt +
599			argument(3)((t-2.0)t+1.0)*t +
600			argument(4)(t-1.0)t*t );
601	greg	1.6	}
602
603
604			double
605	greg	2.12	l_bezier(char *nm)
606	greg	1.6	{
607			double t;
608
609			t = argument(5);
610			return( argument(1) * (1.+t(-3.+t(3.-t))) +
611			argument(2) * 3.t(1.+t*(-2.+t)) +
612			argument(3) * 3.tt*(1.-t) +
613			argument(4) * ttt );
614	greg	1.7	}
615
616
617			double
618	greg	2.12	l_bspline(char *nm)
619	greg	1.7	{
620			double t;
621
622			t = argument(5);
623			return( argument(1) * (1./6.+t(-1./2.+t(1./2.-1./6.*t))) +
624			argument(2) * (2./3.+tt(-1.+1./2.*t)) +
625			argument(3) * (1./6.+t(1./2.+t(1./2.-1./2.*t))) +
626			argument(4) * (1./6.tt*t) );
627	greg	1.1	}