src/gen/gensurf.c

#ifndef lint
static const char RCSid[] = "$Id: gensurf.c,v 2.22 2013/12/09 22:08:13 greg 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[] = "%18.12g %18.12g %18.12g\n";
char  tsargs[] = "4 surf_dx surf_dy surf_dz surf.cal";
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) */
        int  nvalid;    /* normal is valid */
        FVECT  p;       /* vertex position */
        FVECT  n;       /* average normal */
        RREAL  uv[2];   /* (u,v) position */
} POINT;

int  nverts = 0;                /* vertex output count */
int  nnorms = 0;                /* normal output count */

void loaddata(char *file, int m, int n, int pointsize);
double l_dataval(char *nam);
void putobjrow(POINT *rp, int n);
void putobjvert(POINT *p);
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][-o][-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];
        int  size;
        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(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;
        int  i, j;
        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 */
        POINT  *rp,
        int  n
)
{
        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]);
                        rp->nvalid = ++nnorms;
                } else
                        rp->nvalid = 0;
                printf("\tvt %.9g %.9g\n", rp->uv[0], rp->uv[1]);
                rp->valid = ++nverts;
        }
}


void
putobjvert(             /* put out OBJ vertex index triplet */
        POINT *p
)
{
        int     pti = p->valid ? p->valid-nverts-1 : 0;
        int     ni = p->nvalid ? p->nvalid-nnorms-1 : 0;
        
        printf(" %d/%d/%d", pti, pti, ni);
}


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 */
                if (ok1 & ok2 && fdot(vc1,vc2) >= 1.0-FTINY*FTINY) {
                        putc('f', stdout);
                        putobjvert(p0); putobjvert(p1);
                        putobjvert(p3); putobjvert(p2);
                        putc('\n', stdout);
                        return;
                }
                if (ok1) {
                        putc('f', stdout);
                        putobjvert(p0); putobjvert(p1); putobjvert(p2);
                        putc('\n', stdout);
                }
                if (ok2) {
                        putc('f', stdout);
                        putobjvert(p2); putobjvert(p1); putobjvert(p3);
                        putc('\n', stdout);
                }
                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%s\n", texname, 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%s\n", texname, 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%s\n", texname, 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,
        POINT  *row,
        int  siz
)
{
        double  st[2];
        int  end;
        int  checkvalid;
        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 */
        POINT  *r0,
        POINT  *r1,
        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 */
        FVECT  resmat[4],
        POINT  *p0,
        POINT  *p1,
        POINT  *p2,
        POINT  *p3
)
{
#define u  ((ax+1)%3)
#define v  ((ax+2)%3)

        int  ax;
        MAT4  eqnmat;
        FVECT  v1;
        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:	2.23
Committed:	Sat Jan 28 23:09:24 2017 UTC (7 years, 3 months ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad5R1
Changes since 2.22:	+30 -19 lines
Log Message:	Changed to relative vertex indexing, so we can concatenate OBJ output
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.23	static const char RCSid[] = "$Id: gensurf.c,v 2.22 2013/12/09 22:08:13 greg 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	greg	2.18	char vformat[] = "%18.12g %18.12g %18.12g\n";
38	greg	2.19	char tsargs[] = "4 surf_dx surf_dy surf_dz surf.cal";
39	greg	1.3	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	2.21	int nvalid; /* normal is valid */
62	greg	1.3	FVECT p; /* vertex position */
63			FVECT n; /* average normal */
64	schorsch	2.11	RREAL uv[2]; /* (u,v) position */
65	greg	1.3	} POINT;
66
67	greg	2.23	int nverts = 0; /* vertex output count */
68			int nnorms = 0; /* normal output count */
69	greg	1.3
70	schorsch	2.13	void loaddata(char *file, int m, int n, int pointsize);
71			double l_dataval(char *nam);
72			void putobjrow(POINT *rp, int n);
73	greg	2.23	void putobjvert(POINT *p);
74	schorsch	2.13	void putsquare(POINT p0, POINT p1, POINT p2, POINT p3);
75			void comprow(double s, POINT *row, int siz);
76			void compnorms(POINT r0, POINT r1, POINT *r2, int siz);
77			int norminterp(FVECT resmat[4], POINT p0, POINT p1, POINT p2, POINT p3);
78
79
80			int
81	greg	1.1	main(argc, argv)
82			int argc;
83			char *argv[];
84			{
85	greg	1.3	POINT row0, row1, row2, rp;
86	greg	1.1	int i, j, m, n;
87			char stmp[256];
88
89	greg	1.13	varset("PI", ':', PI);
90	greg	1.14	funset("hermite", 5, ':', l_hermite);
91			funset("bezier", 5, ':', l_bezier);
92			funset("bspline", 5, ':', l_bspline);
93	greg	1.1
94			if (argc < 8)
95			goto userror;
96
97			for (i = 8; i < argc; i++)
98			if (!strcmp(argv[i], "-e"))
99	greg	1.10	scompile(argv[++i], NULL, 0);
100	greg	1.1	else if (!strcmp(argv[i], "-f"))
101			fcompile(argv[++i]);
102	greg	1.3	else if (!strcmp(argv[i], "-s"))
103			smooth++;
104	greg	2.7	else if (!strcmp(argv[i], "-o"))
105			objout++;
106	greg	1.1	else
107			goto userror;
108
109	greg	1.3	modname = argv[1];
110			surfname = argv[2];
111	greg	1.1	m = atoi(argv[6]);
112			n = atoi(argv[7]);
113			if (m <= 0 \|\| n <= 0)
114			goto userror;
115	greg	2.2	if (!strcmp(argv[5], "-") \|\| access(argv[5], 4) == 0) { /* file? */
116			funset(ZNAME, 2, ':', l_dataval);
117			if (!strcmp(argv[5],argv[3]) && !strcmp(argv[5],argv[4])) {
118			loaddata(argv[5], m, n, 3);
119			funset(XNAME, 2, ':', l_dataval);
120			funset(YNAME, 2, ':', l_dataval);
121			} else {
122			loaddata(argv[5], m, n, 1);
123			sprintf(stmp, "%s(s,t)=%s;", XNAME, argv[3]);
124			scompile(stmp, NULL, 0);
125			sprintf(stmp, "%s(s,t)=%s;", YNAME, argv[4]);
126			scompile(stmp, NULL, 0);
127			}
128			} else {
129			sprintf(stmp, "%s(s,t)=%s;", XNAME, argv[3]);
130			scompile(stmp, NULL, 0);
131			sprintf(stmp, "%s(s,t)=%s;", YNAME, argv[4]);
132			scompile(stmp, NULL, 0);
133			sprintf(stmp, "%s(s,t)=%s;", ZNAME, argv[5]);
134			scompile(stmp, NULL, 0);
135			}
136	greg	1.4	row0 = (POINT )malloc((n+3)sizeof(POINT));
137			row1 = (POINT )malloc((n+3)sizeof(POINT));
138			row2 = (POINT )malloc((n+3)sizeof(POINT));
139	greg	1.3	if (row0 == NULL \|\| row1 == NULL \|\| row2 == NULL) {
140	greg	1.1	fprintf(stderr, "%s: out of memory\n", argv[0]);
141			quit(1);
142			}
143	greg	1.4	row0++; row1++; row2++;
144	greg	1.3	/* print header */
145	greg	2.16	fputs("# ", stdout);
146			printargs(argc, argv, stdout);
147	greg	1.9	eclock = 0;
148	greg	1.4	/* initialize */
149			comprow(-1.0/m, row0, n);
150	greg	1.3	comprow(0.0, row1, n);
151			comprow(1.0/m, row2, n);
152	greg	1.4	compnorms(row0, row1, row2, n);
153	greg	2.8	if (objout) {
154			printf("\nusemtl %s\n\n", modname);
155	greg	2.7	putobjrow(row1, n);
156	greg	2.8	}
157	greg	1.3	/* for each row */
158	greg	1.1	for (i = 0; i < m; i++) {
159			/* compute next row */
160	greg	1.3	rp = row0;
161	greg	1.1	row0 = row1;
162	greg	1.3	row1 = row2;
163			row2 = rp;
164	greg	1.4	comprow((double)(i+2)/m, row2, n);
165			compnorms(row0, row1, row2, n);
166	greg	2.7	if (objout)
167			putobjrow(row1, n);
168	greg	1.1
169			for (j = 0; j < n; j++) {
170	greg	2.6	int orient = (j & 1);
171	greg	1.3	/* put polygons */
172	greg	2.7	if (!(row0[j].valid && row1[j+1].valid))
173	greg	2.6	orient = 1;
174	greg	2.7	else if (!(row1[j].valid && row0[j+1].valid))
175	greg	2.6	orient = 0;
176			if (orient)
177	greg	1.3	putsquare(&row0[j], &row1[j],
178			&row0[j+1], &row1[j+1]);
179			else
180			putsquare(&row1[j], &row1[j+1],
181			&row0[j], &row0[j+1]);
182	greg	1.1	}
183			}
184
185	schorsch	2.13	return 0;
186	greg	1.1
187			userror:
188			fprintf(stderr, "Usage: %s material name ", argv[0]);
189	greg	2.17	fprintf(stderr, "x(s,t) y(s,t) z(s,t) m n [-s][-o][-e expr][-f file]\n");
190	schorsch	2.13	return 1;
191	greg	2.2	}
192
193
194	schorsch	2.13	void
195			loaddata( /* load point data from file */
196			char *file,
197			int m,
198			int n,
199			int pointsize
200			)
201	greg	2.2	{
202			FILE *fp;
203			char word[64];
204	greg	2.22	int size;
205			RREAL *dp;
206	greg	2.2
207			datarec.flags = HASBORDER; /* assume border values */
208	greg	2.3	datarec.m = m+1;
209			datarec.n = n+1;
210			size = datarec.mdatarec.npointsize;
211	greg	2.2	if (pointsize == 3)
212			datarec.flags \|= TRIPLETS;
213	schorsch	2.11	dp = (RREAL )malloc(sizesizeof(RREAL));
214	greg	2.2	if ((datarec.data = dp) == NULL) {
215			fputs("Out of memory\n", stderr);
216			exit(1);
217			}
218			if (!strcmp(file, "-")) {
219			file = "<stdin>";
220			fp = stdin;
221			} else if ((fp = fopen(file, "r")) == NULL) {
222			fputs(file, stderr);
223			fputs(": cannot open\n", stderr);
224			exit(1);
225			}
226			while (size > 0 && fgetword(word, sizeof(word), fp) != NULL) {
227			if (!isflt(word)) {
228			fprintf(stderr, "%s: garbled data value: %s\n",
229			file, word);
230			exit(1);
231			}
232			*dp++ = atof(word);
233			size--;
234			}
235			if (size == (m+n+1)pointsize) { / no border after all */
236	greg	2.20	dp = (RREAL *)realloc(datarec.data,
237	schorsch	2.11	mnpointsize*sizeof(RREAL));
238	greg	2.2	if (dp != NULL)
239			datarec.data = dp;
240			datarec.flags &= ~HASBORDER;
241	greg	2.3	datarec.m = m;
242			datarec.n = n;
243	greg	2.2	size = 0;
244			}
245	greg	2.3	if (datarec.m < 2 \|\| datarec.n < 2 \|\| size != 0 \|\|
246			fgetword(word, sizeof(word), fp) != NULL) {
247	greg	2.2	fputs(file, stderr);
248			fputs(": bad number of data points\n", stderr);
249			exit(1);
250			}
251			fclose(fp);
252			}
253
254
255			double
256	schorsch	2.13	l_dataval( /* return recorded data value */
257			char *nam
258			)
259	greg	2.2	{
260			double u, v;
261	greg	2.22	int i, j;
262			RREAL *dp;
263	greg	2.2	double d00, d01, d10, d11;
264			/* compute coordinates */
265			u = argument(1); v = argument(2);
266			if (datarec.flags & HASBORDER) {
267	greg	2.3	i = u *= datarec.m-1;
268			j = v *= datarec.n-1;
269	greg	2.2	} else {
270	greg	2.3	i = u = u*datarec.m - .5;
271			j = v = v*datarec.n - .5;
272	greg	2.2	}
273			if (i < 0) i = 0;
274			else if (i > datarec.m-2) i = datarec.m-2;
275			if (j < 0) j = 0;
276			else if (j > datarec.n-2) j = datarec.n-2;
277			/* compute value */
278			if (datarec.flags & TRIPLETS) {
279	greg	2.3	dp = datarec.data + 3(jdatarec.m + i);
280			if (nam == ZNAME)
281			dp += 2;
282			else if (nam == YNAME)
283	greg	2.2	dp++;
284			d00 = dp[0]; d01 = dp[3];
285	greg	2.3	dp += 3*datarec.m;
286	greg	2.2	d10 = dp[0]; d11 = dp[3];
287			} else {
288	greg	2.3	dp = datarec.data + j*datarec.m + i;
289	greg	2.2	d00 = dp[0]; d01 = dp[1];
290	greg	2.3	dp += datarec.m;
291	greg	2.2	d10 = dp[0]; d11 = dp[1];
292			}
293			/* bilinear interpolation */
294			return((j+1-v)((i+1-u)d00+(u-i)d01)+(v-j)((i+1-u)d10+(u-i)d11));
295	greg	1.1	}
296
297
298	schorsch	2.13	void
299			putobjrow( /* output vertex row to .OBJ */
300	greg	2.22	POINT *rp,
301	schorsch	2.13	int n
302			)
303	greg	2.7	{
304			for ( ; n-- >= 0; rp++) {
305			if (!rp->valid)
306			continue;
307			fputs("v ", stdout);
308	greg	2.9	pvect(rp->p);
309	greg	2.21	if (smooth && !ZEROVECT(rp->n)) {
310	greg	2.7	printf("\tvn %.9g %.9g %.9g\n",
311			rp->n[0], rp->n[1], rp->n[2]);
312	greg	2.21	rp->nvalid = ++nnorms;
313			} else
314			rp->nvalid = 0;
315	greg	2.7	printf("\tvt %.9g %.9g\n", rp->uv[0], rp->uv[1]);
316			rp->valid = ++nverts;
317			}
318			}
319
320
321	schorsch	2.13	void
322	greg	2.23	putobjvert( /* put out OBJ vertex index triplet */
323			POINT *p
324			)
325			{
326			int pti = p->valid ? p->valid-nverts-1 : 0;
327			int ni = p->nvalid ? p->nvalid-nnorms-1 : 0;
328
329			printf(" %d/%d/%d", pti, pti, ni);
330			}
331
332
333			void
334	schorsch	2.13	putsquare( /* put out a square */
335			POINT *p0,
336			POINT *p1,
337			POINT *p2,
338			POINT *p3
339			)
340	greg	1.3	{
341			static int nout = 0;
342			FVECT norm[4];
343			int axis;
344			FVECT v1, v2, vc1, vc2;
345			int ok1, ok2;
346			/* compute exact normals */
347	greg	2.7	ok1 = (p0->valid && p1->valid && p2->valid);
348	greg	2.6	if (ok1) {
349	greg	2.9	VSUB(v1, p1->p, p0->p);
350			VSUB(v2, p2->p, p0->p);
351	greg	2.6	fcross(vc1, v1, v2);
352			ok1 = (normalize(vc1) != 0.0);
353			}
354	greg	2.7	ok2 = (p1->valid && p2->valid && p3->valid);
355	greg	2.6	if (ok2) {
356	greg	2.9	VSUB(v1, p2->p, p3->p);
357			VSUB(v2, p1->p, p3->p);
358	greg	2.6	fcross(vc2, v1, v2);
359			ok2 = (normalize(vc2) != 0.0);
360			}
361	greg	1.3	if (!(ok1 \| ok2))
362			return;
363	greg	2.7	if (objout) { /* output .OBJ faces */
364			if (ok1 & ok2 && fdot(vc1,vc2) >= 1.0-FTINY*FTINY) {
365	greg	2.23	putc('f', stdout);
366			putobjvert(p0); putobjvert(p1);
367			putobjvert(p3); putobjvert(p2);
368			putc('\n', stdout);
369	greg	2.7	return;
370			}
371	greg	2.23	if (ok1) {
372			putc('f', stdout);
373			putobjvert(p0); putobjvert(p1); putobjvert(p2);
374			putc('\n', stdout);
375			}
376			if (ok2) {
377			putc('f', stdout);
378			putobjvert(p2); putobjvert(p1); putobjvert(p3);
379			putc('\n', stdout);
380			}
381	greg	2.7	return;
382			}
383	greg	1.3	/* compute normal interpolation */
384			axis = norminterp(norm, p0, p1, p2, p3);
385
386			/* put out quadrilateral? */
387			if (ok1 & ok2 && fdot(vc1,vc2) >= 1.0-FTINY*FTINY) {
388			printf("\n%s ", modname);
389			if (axis != -1) {
390	greg	2.19	printf("texfunc %s\n%s\n", texname, tsargs);
391	greg	1.3	printf("0\n13\t%d\n", axis);
392			pvect(norm[0]);
393			pvect(norm[1]);
394			pvect(norm[2]);
395			fvsum(v1, norm[3], vc1, -0.5);
396			fvsum(v1, v1, vc2, -0.5);
397			pvect(v1);
398			printf("\n%s ", texname);
399			}
400			printf("polygon %s.%d\n", surfname, ++nout);
401			printf("0\n0\n12\n");
402			pvect(p0->p);
403			pvect(p1->p);
404			pvect(p3->p);
405			pvect(p2->p);
406			return;
407			}
408			/* put out triangles? */
409			if (ok1) {
410			printf("\n%s ", modname);
411			if (axis != -1) {
412	greg	2.19	printf("texfunc %s\n%s\n", texname, tsargs);
413	greg	1.3	printf("0\n13\t%d\n", axis);
414			pvect(norm[0]);
415			pvect(norm[1]);
416			pvect(norm[2]);
417			fvsum(v1, norm[3], vc1, -1.0);
418			pvect(v1);
419			printf("\n%s ", texname);
420			}
421			printf("polygon %s.%d\n", surfname, ++nout);
422			printf("0\n0\n9\n");
423			pvect(p0->p);
424			pvect(p1->p);
425			pvect(p2->p);
426			}
427			if (ok2) {
428			printf("\n%s ", modname);
429			if (axis != -1) {
430	greg	2.19	printf("texfunc %s\n%s\n", texname, tsargs);
431	greg	1.3	printf("0\n13\t%d\n", axis);
432			pvect(norm[0]);
433			pvect(norm[1]);
434			pvect(norm[2]);
435			fvsum(v2, norm[3], vc2, -1.0);
436			pvect(v2);
437			printf("\n%s ", texname);
438			}
439			printf("polygon %s.%d\n", surfname, ++nout);
440			printf("0\n0\n9\n");
441			pvect(p2->p);
442			pvect(p1->p);
443			pvect(p3->p);
444			}
445			}
446
447
448	schorsch	2.13	void
449			comprow( /* compute row of values */
450			double s,
451	greg	2.22	POINT *row,
452	schorsch	2.13	int siz
453			)
454	greg	1.1	{
455	greg	1.4	double st[2];
456	greg	1.8	int end;
457	greg	2.6	int checkvalid;
458	greg	2.22	int i;
459	greg	1.8
460			if (smooth) {
461			i = -1; /* compute one past each end */
462			end = siz+1;
463			} else {
464			if (s < -FTINY \|\| s > 1.0+FTINY)
465			return;
466			i = 0;
467			end = siz;
468			}
469	greg	1.1	st[0] = s;
470	greg	2.6	checkvalid = (fundefined(VNAME) == 2);
471	greg	1.8	while (i <= end) {
472	greg	1.4	st[1] = (double)i/siz;
473	greg	2.6	if (checkvalid && funvalue(VNAME, 2, st) <= 0.0) {
474			row[i].valid = 0;
475			row[i].p[0] = row[i].p[1] = row[i].p[2] = 0.0;
476	greg	2.7	row[i].uv[0] = row[i].uv[1] = 0.0;
477	greg	2.6	} else {
478			row[i].valid = 1;
479			row[i].p[0] = funvalue(XNAME, 2, st);
480			row[i].p[1] = funvalue(YNAME, 2, st);
481			row[i].p[2] = funvalue(ZNAME, 2, st);
482	greg	2.7	row[i].uv[0] = st[0];
483			row[i].uv[1] = st[1];
484	greg	2.6	}
485	greg	1.8	i++;
486	greg	1.1	}
487	greg	1.3	}
488
489
490	schorsch	2.13	void
491			compnorms( /* compute row of averaged normals */
492	greg	2.22	POINT *r0,
493			POINT *r1,
494			POINT *r2,
495	schorsch	2.13	int siz
496			)
497	greg	1.3	{
498	greg	1.11	FVECT v1, v2;
499	greg	1.3
500			if (!smooth) /* not needed if no smoothing */
501			return;
502	greg	2.6	/* compute row 1 normals */
503	greg	1.4	while (siz-- >= 0) {
504	greg	2.6	if (!r1[0].valid)
505			continue;
506			if (!r0[0].valid) {
507			if (!r2[0].valid) {
508			r1[0].n[0] = r1[0].n[1] = r1[0].n[2] = 0.0;
509			continue;
510			}
511			fvsum(v1, r2[0].p, r1[0].p, -1.0);
512			} else if (!r2[0].valid)
513			fvsum(v1, r1[0].p, r0[0].p, -1.0);
514			else
515			fvsum(v1, r2[0].p, r0[0].p, -1.0);
516			if (!r1[-1].valid) {
517			if (!r1[1].valid) {
518			r1[0].n[0] = r1[0].n[1] = r1[0].n[2] = 0.0;
519			continue;
520			}
521			fvsum(v2, r1[1].p, r1[0].p, -1.0);
522			} else if (!r1[1].valid)
523			fvsum(v2, r1[0].p, r1[-1].p, -1.0);
524			else
525			fvsum(v2, r1[1].p, r1[-1].p, -1.0);
526	greg	1.3	fcross(r1[0].n, v1, v2);
527			normalize(r1[0].n);
528			r0++; r1++; r2++;
529			}
530			}
531
532
533			int
534	schorsch	2.13	norminterp( /* compute normal interpolation */
535	greg	2.22	FVECT resmat[4],
536	schorsch	2.13	POINT *p0,
537			POINT *p1,
538			POINT *p2,
539			POINT *p3
540			)
541	greg	1.3	{
542			#define u ((ax+1)%3)
543			#define v ((ax+2)%3)
544
545	greg	2.22	int ax;
546	greg	1.12	MAT4 eqnmat;
547	greg	1.3	FVECT v1;
548	greg	2.22	int i, j;
549	greg	1.3
550			if (!smooth) /* no interpolation if no smoothing */
551			return(-1);
552			/* find dominant axis */
553			VCOPY(v1, p0->n);
554			fvsum(v1, v1, p1->n, 1.0);
555			fvsum(v1, v1, p2->n, 1.0);
556			fvsum(v1, v1, p3->n, 1.0);
557	greg	1.4	ax = ABS(v1[0]) > ABS(v1[1]) ? 0 : 1;
558			ax = ABS(v1[ax]) > ABS(v1[2]) ? ax : 2;
559	greg	1.3	/* assign equation matrix */
560			eqnmat[0][0] = p0->p[u]*p0->p[v];
561			eqnmat[0][1] = p0->p[u];
562			eqnmat[0][2] = p0->p[v];
563			eqnmat[0][3] = 1.0;
564			eqnmat[1][0] = p1->p[u]*p1->p[v];
565			eqnmat[1][1] = p1->p[u];
566			eqnmat[1][2] = p1->p[v];
567			eqnmat[1][3] = 1.0;
568			eqnmat[2][0] = p2->p[u]*p2->p[v];
569			eqnmat[2][1] = p2->p[u];
570			eqnmat[2][2] = p2->p[v];
571			eqnmat[2][3] = 1.0;
572			eqnmat[3][0] = p3->p[u]*p3->p[v];
573			eqnmat[3][1] = p3->p[u];
574			eqnmat[3][2] = p3->p[v];
575			eqnmat[3][3] = 1.0;
576			/* invert matrix (solve system) */
577	greg	2.5	if (!invmat4(eqnmat, eqnmat))
578	greg	1.3	return(-1); /* no solution */
579			/* compute result matrix */
580			for (j = 0; j < 4; j++)
581			for (i = 0; i < 3; i++)
582	greg	1.4	resmat[j][i] = eqnmat[j][0]*p0->n[i] +
583			eqnmat[j][1]*p1->n[i] +
584			eqnmat[j][2]*p2->n[i] +
585			eqnmat[j][3]*p3->n[i];
586	greg	1.3	return(ax);
587
588			#undef u
589			#undef v
590	greg	1.1	}
591
592
593			double
594	greg	2.12	l_hermite(char *nm)
595	greg	1.1	{
596			double t;
597
598			t = argument(5);
599			return( argument(1)((2.0t-3.0)tt+1.0) +
600			argument(2)(-2.0t+3.0)tt +
601			argument(3)((t-2.0)t+1.0)*t +
602			argument(4)(t-1.0)t*t );
603	greg	1.6	}
604
605
606			double
607	greg	2.12	l_bezier(char *nm)
608	greg	1.6	{
609			double t;
610
611			t = argument(5);
612			return( argument(1) * (1.+t(-3.+t(3.-t))) +
613			argument(2) * 3.t(1.+t*(-2.+t)) +
614			argument(3) * 3.tt*(1.-t) +
615			argument(4) * ttt );
616	greg	1.7	}
617
618
619			double
620	greg	2.12	l_bspline(char *nm)
621	greg	1.7	{
622			double t;
623
624			t = argument(5);
625			return( argument(1) * (1./6.+t(-1./2.+t(1./2.-1./6.*t))) +
626			argument(2) * (2./3.+tt(-1.+1./2.*t)) +
627			argument(3) * (1./6.+t(1./2.+t(1./2.-1./2.*t))) +
628			argument(4) * (1./6.tt*t) );
629	greg	1.1	}