static int
puttri( /* convert a triangle */
char *v1,
char *v2,
char *v3
)
{
VNDX v1i, v2i, v3i;
RREAL *v1c, *v2c, *v3c;
RREAL *v1n, *v2n, *v3n;
if (!cvtndx(v1i, v1) || !cvtndx(v2i, v2) || !cvtndx(v3i, v3)) {
error(WARNING, "bad vertex reference");
return(0);
}
if (v1i[1]>=0 && v2i[1]>=0 && v3i[1]>=0) {
v1c = vtlist[v1i[1]];
v2c = vtlist[v2i[1]];
v3c = vtlist[v3i[1]];
} else
v1c = v2c = v3c = NULL;
if (v1i[2]>=0 && v2i[2]>=0 && v3i[2]>=0) {
v1n = vnlist[v1i[2]];
v2n = vnlist[v2i[2]];
v3n = vnlist[v3i[2]];
} else
v1n = v2n = v3n = NULL;
return(cvtri(getmod(), vlist[v1i[0]], vlist[v2i[0]], vlist[v3i[0]],
v1n, v2n, v3n, v1c, v2c, v3c) >= 0);
}
int
nonplanar( /* are vertices non-planar? */
int ac,
char **av
)
{
VNDX vi;
RREAL *p0, *p1;
FVECT v1, v2, nsum, newn;
double d;
int i;
if (!cvtndx(vi, av[0]))
return(0);
if (!flatten && vi[2] >= 0)
return(1); /* has interpolated normals */
if (ac < 4)
return(0); /* it's a triangle! */
/* set up */
p0 = vlist[vi[0]];
if (!cvtndx(vi, av[1]))
return(0); /* error gets caught later */
nsum[0] = nsum[1] = nsum[2] = 0.;
p1 = vlist[vi[0]];
fvsum(v2, p1, p0, -1.0);
for (i = 2; i < ac; i++) {
VCOPY(v1, v2);
if (!cvtndx(vi, av[i]))
return(0);
p1 = vlist[vi[0]];
fvsum(v2, p1, p0, -1.0);
fcross(newn, v1, v2);
if (normalize(newn) == 0.0) {
if (i < 3)
return(1); /* can't deal with this */
fvsum(nsum, nsum, nsum, 1./(i-2));
continue;
}
d = fdot(newn,nsum);
if (d >= 0) {
if (d < (1.0-FTINY)*(i-2))
return(1);
fvsum(nsum, nsum, newn, 1.0);
} else {
if (d > -(1.0-FTINY)*(i-2))
return(1);
fvsum(nsum, nsum, newn, -1.0);
}
}
return(0);
}
int
putface( /* put out an N-sided polygon */
int ac,
char **av
)
{
VNDX vi;
char *cp;
int i;
if (nonplanar(ac, av)) { /* break into triangles */
while (ac > 2) {
if (!puttri(av[0], av[1], av[2]))
return(0);
ac--; /* remove vertex & rotate */
cp = av[0];
for (i = 0; i < ac-1; i++)
av[i] = av[i+2];
av[i] = cp;
}
return(1);
}
if ((cp = getmtl()) == NULL)
return(-1);
printf("\n%s polygon %s.%d\n", cp, getonm(), faceno);
printf("0\n0\n%d\n", 3*ac);
for (i = 0; i < ac; i++) {
if (!cvtndx(vi, av[i]))
return(0);
pvect(vlist[vi[0]]);
}
return(1);
}
/* determine dominant axis for triangle */
static int
dominant_axis(char *v1, char *v2, char *v3)
{
VNDX v1i, v2i, v3i;
FVECT e1, e2, vn;
int i, imax;
if (!cvtndx(v1i, v1) || !cvtndx(v2i, v2) || !cvtndx(v3i, v3))
return(-1);
VSUB(e1, vlist[v2i[0]], vlist[v1i[0]]);
VSUB(e2, vlist[v3i[0]], vlist[v2i[0]]);
VCROSS(vn, e1, e2);
for (i = imax = 2; i--; )
if (vn[i]*vn[i] > vn[imax]*vn[imax])
imax = i;
return(vn[imax]*vn[imax] > FTINY*FTINY ? imax : -1);
}
static int
putface( /* put out an N-sided polygon */
int ac,
char **av
)
{
Vert2_list *poly = polyAlloc(ac);
int i, ax, ay;
if (poly == NULL)
return(0);
poly->p = (void *)av;
for (i = ac-3; i >= 0; i--) /* identify dominant axis */
if ((ax = dominant_axis(av[i], av[i+1], av[i+2])) >= 0)
break;
if (ax < 0)
return(1); /* ignore degenerate face */
if (++ax >= 3) ax = 0;
ay = ax;
if (++ay >= 3) ay = 0;
for (i = 0; i < ac; i++) { /* convert to 2-D polygon */
VNDX vi;
if (!cvtndx(vi, av[i])) {
error(WARNING, "bad vertex reference");
polyFree(poly);
return(0);
}
poly->v[i].mX = vlist[vi[0]][ax];
poly->v[i].mY = vlist[vi[0]][ay];
}
/* break into triangles & output */
if (!polyTriangulate(poly, &tri_out)) {
sprintf(errmsg, "self-intersecting face with %d vertices", ac);
error(WARNING, errmsg);
}
polyFree(poly);
return(1);
}
int
puttri( /* put out a triangle */
char *v1,
char *v2,
char *v3
)
{
char *mod;
VNDX v1i, v2i, v3i;
BARYCCM bvecs;
RREAL bcoor[3][3];
int texOK = 0, patOK;
int flatness;
int i;
if ((mod = getmtl()) == NULL)
return(-1);
if (!cvtndx(v1i, v1) || !cvtndx(v2i, v2) || !cvtndx(v3i, v3))
return(0);
/* compute barycentric coordinates */
if (v1i[2]>=0 && v2i[2]>=0 && v3i[2]>=0)
flatness = flat_tri(vlist[v1i[0]], vlist[v2i[0]], vlist[v3i[0]],
vnlist[v1i[2]], vnlist[v2i[2]], vnlist[v3i[2]]);
else
flatness = ISFLAT;
switch (flatness) {
case DEGEN: /* zero area */
ndegen++;
return(-1);
case RVFLAT: /* reversed normals, but flat */
case ISFLAT: /* smoothing unnecessary */
texOK = 0;
break;
case RVBENT: /* reversed normals with smoothing */
case ISBENT: /* proper smoothing */
texOK = 1;
break;
}
if (flatten)
texOK = 0;
#ifdef TEXMAPS
patOK = mapname[0] && (v1i[1]>=0 && v2i[1]>=0 && v3i[1]>=0);
#else
patOK = 0;
#endif
if (texOK | patOK)
if (comp_baryc(&bvecs, vlist[v1i[0]], vlist[v2i[0]],
vlist[v3i[0]]) < 0)
texOK = patOK = 0;
/* put out texture (if any) */
if (texOK) {
printf("\n%s texfunc %s\n", mod, TEXNAME);
mod = TEXNAME;
printf("4 dx dy dz %s\n", TCALNAME);
printf("0\n");
for (i = 0; i < 3; i++) {
bcoor[i][0] = vnlist[v1i[2]][i];
bcoor[i][1] = vnlist[v2i[2]][i];
bcoor[i][2] = vnlist[v3i[2]][i];
}
put_baryc(&bvecs, bcoor, 3);
}
#ifdef TEXMAPS
/* put out pattern (if any) */
if (patOK) {
printf("\n%s colorpict %s\n", mod, PATNAME);
mod = PATNAME;
printf("7 noneg noneg noneg %s %s u v\n", mapname, TCALNAME);
printf("0\n");
for (i = 0; i < 2; i++) {
bcoor[i][0] = vtlist[v1i[1]][i];
bcoor[i][1] = vtlist[v2i[1]][i];
bcoor[i][2] = vtlist[v3i[1]][i];
}
put_baryc(&bvecs, bcoor, 2);
}
#endif
/* put out (reversed) triangle */
printf("\n%s polygon %s.%d\n", mod, getonm(), faceno);
printf("0\n0\n9\n");
if (flatness == RVFLAT || flatness == RVBENT) {
pvect(vlist[v3i[0]]);
pvect(vlist[v2i[0]]);
pvect(vlist[v1i[0]]);
} else {
pvect(vlist[v1i[0]]);
pvect(vlist[v2i[0]]);
pvect(vlist[v3i[0]]);
}
return(1);
}