void
scale_along_normal(
CGEOMptr &obj,
CWpt &scale_cent,
CWpt &down_pt,
CWvec &down_norm,
CXYpt &cur
)
{
Wtransf xf (obj->xform());
Wpt dpt (xf * down_pt);
Wpt spt (xf * scale_cent);
Wvec upv ((xf * down_norm).normalized());
if (upv * (dpt - spt) < 0)
upv = -upv;
if ((cur - XYpt(dpt)).length() < 0.01)
return;
Wpt npt(Wline(dpt,upv).intersect(cur));
Wpt ctr(xf * scale_cent);
double sval(((npt-dpt) * upv) / (dpt-ctr).length());
if ((npt-ctr) * (dpt-ctr) < 0)
return;
Wvec dnorm (fabs(down_norm[0]),fabs(down_norm[1]),
fabs(down_norm[2]));
((GEOMptr)obj)->set_xform(xf *
Wtransf::scaling(scale_cent,
(dnorm*sval+Wvec(1,1,1))));
}
RAYhit &
LINE3D::intersect(
RAYhit &ray,
CWtransf&,
int
) const
{
// Find the intersection point, its distance, and some kind of normal
double distance = -1, d_2d = -1;
Wvec surf_norm;
Wpt nearpt;
for (int i=0; i<num()-1; i++) {
// Find the nearest point on the ray to the segment.
Wpt ray_pt = ray.line().intersect(Wline(point(i), point(i+1)));
// Accept only if ray_pt is in front of the ray
if ((ray_pt - ray.point()) * ray.vec() > 0 ) {
// Ok if the ray passes within 10 pixels of the segment
const double PIX_THRESH = 10.0;
Wpt hit_pt = nearest_pt_to_line_seg(ray_pt, point(i), point(i+1));
double screen_dist = PIXEL(hit_pt).dist(ray_pt);
if ((screen_dist < PIX_THRESH) && (d_2d < 0 || screen_dist < d_2d)) {
d_2d = screen_dist;
distance = ray.point().dist(ray_pt);
nearpt = hit_pt;
// XXX - What should be the "normal"? For now,
// just the vector pointing back to the camera.
surf_norm = -ray.vec().normalized();
}
}
}
// Then call ray.check() passing it all this stuff
if (distance >= 0)
ray.check(distance, 1, 0, (GEL*)this, surf_norm, nearpt, nearpt,
0, XYpt());
return ray;
}
