int ON_ArcCurve::GetNurbForm( // returns 0: unable to create NURBS representation
// with desired accuracy.
// 1: success - returned NURBS parameterization
// matches the curve's to wthe desired accuracy
// 2: success - returned NURBS point locus matches
// the curve's to the desired accuracy but, on
// the interior of the curve's domain, the
// curve's parameterization and the NURBS
// parameterization may not match to the
// desired accuracy.
ON_NurbsCurve& c,
double tolerance,
const ON_Interval* subdomain // OPTIONAL subdomain of arc
) const
{
int rc = 0;
if ( subdomain )
{
ON_ArcCurve trimmed_arc(*this);
if ( trimmed_arc.Trim(*subdomain) )
{
rc = trimmed_arc.GetNurbForm( c, tolerance, NULL );
}
}
else if ( m_t.IsIncreasing() && m_arc.IsValid() )
{
if ( NurbsCurveArc( m_arc, m_dim, c ) )
{
rc = 2;
c.SetDomain( m_t[0], m_t[1] );
}
}
return rc;
}
int
ON_CurveProxy::GetNurbForm( // returns 0: unable to create NURBS representation
// with desired accuracy.
// 1: success - returned NURBS parameterization
// matches the curve's to wthe desired accuracy
// 2: success - returned NURBS point locus matches
// the curve's to the desired accuracy but, on
// the interior of the curve's domain, the
// curve's parameterization and the NURBS
// parameterization may not match to the
// desired accuracy.
ON_NurbsCurve& nurbs,
double tolerance, // (>=0)
const ON_Interval* sub_domain // OPTIONAL subdomain of ON::ProxyCurve::Domain()
) const
{
ON_BOOL32 rc = false;
if ( m_real_curve )
{
ON_Interval scratch_domain = RealCurveInterval( sub_domain );
rc = m_real_curve->GetNurbForm(nurbs,tolerance,&scratch_domain);
if ( rc )
{
if ( m_bReversed )
nurbs.Reverse();
ON_Interval d = m_this_domain;
if ( sub_domain )
d.Intersection( *sub_domain );
nurbs.SetDomain( d[0], d[1] );
if ( nurbs.m_dim <= 3 && nurbs.m_dim >= 1 )
{
double t0 = Domain()[0];
double t1 = Domain()[1];
if ( 0 != sub_domain )
{
if ( t0 < sub_domain->Min() )
t0 = sub_domain->Min();
if ( sub_domain->Max() < t1 )
t1 = sub_domain->Max();
}
// set ends of NURBS curve to be exactly on ends of proxy curve
ON_3dPoint P0 = PointAt(t0);
ON_3dPoint P1 = PointAt(t1);
ON_3dPoint N0 = nurbs.PointAtStart();
ON_3dPoint N1 = nurbs.PointAtEnd();
// 22 September 2003, GBA. The end tuning code below should only be applied
// to clamped nurbs curves. In particular it should not be used on
// periodic nurbs curves. Fixes TRR#11502.
ON_BOOL32 clamped = nurbs.IsClamped(2);
if ( clamped && (P0 != N0 || P1 != N1) )
{
if ( 0==nurbs.m_is_rat )
{
nurbs.SetCV(0,P0);
nurbs.SetCV(nurbs.m_cv_count-1,P1);
}
else
{
ON_4dPoint H0, H1;
H0 = P0;
H0.w = nurbs.Weight(0);
H0.x *= H0.w;
H0.y *= H0.w;
H0.z *= H0.w;
nurbs.SetCV(0,H0);
H1 = P1;
H1.w = nurbs.Weight(nurbs.m_cv_count-1);
H1.x *= H1.w;
H1.y *= H1.w;
H1.z *= H1.w;
nurbs.SetCV(nurbs.m_cv_count-1,H1);
}
}
}
}
}
return rc;
}
extern "C" void
rt_hyp_brep(ON_Brep **b, const struct rt_db_internal *ip, const struct bn_tol *)
{
struct rt_hyp_internal *eip;
RT_CK_DB_INTERNAL(ip);
eip = (struct rt_hyp_internal *)ip->idb_ptr;
RT_HYP_CK_MAGIC(eip);
point_t p1_origin, p2_origin;
ON_3dPoint plane1_origin, plane2_origin;
ON_3dVector plane_x_dir, plane_y_dir;
// First, find planes corresponding to the top and bottom faces - initially
vect_t x_dir, y_dir;
VMOVE(x_dir, eip->hyp_A);
VCROSS(y_dir, eip->hyp_A, eip->hyp_Hi);
VREVERSE(y_dir, y_dir);
VMOVE(p1_origin, eip->hyp_Vi);
plane1_origin = ON_3dPoint(p1_origin);
plane_x_dir = ON_3dVector(x_dir);
plane_y_dir = ON_3dVector(y_dir);
const ON_Plane hyp_bottom_plane(plane1_origin, plane_x_dir, plane_y_dir);
VADD2(p2_origin, eip->hyp_Vi, eip->hyp_Hi);
plane2_origin = ON_3dPoint(p2_origin);
const ON_Plane hyp_top_plane(plane2_origin, plane_x_dir, plane_y_dir);
// Next, create ellipses in the planes corresponding to the edges of the hyp
ON_Ellipse b_ell(hyp_bottom_plane, MAGNITUDE(eip->hyp_A), eip->hyp_b);
ON_NurbsCurve* bcurve = ON_NurbsCurve::New();
b_ell.GetNurbForm((*bcurve));
bcurve->SetDomain(0.0, 1.0);
ON_Ellipse t_ell(hyp_top_plane, MAGNITUDE(eip->hyp_A), eip->hyp_b);
ON_NurbsCurve* tcurve = ON_NurbsCurve::New();
t_ell.GetNurbForm((*tcurve));
tcurve->SetDomain(0.0, 1.0);
// Generate the bottom cap
ON_SimpleArray<ON_Curve*> boundary;
boundary.Append(ON_Curve::Cast(bcurve));
ON_PlaneSurface* bp = new ON_PlaneSurface();
bp->m_plane = hyp_bottom_plane;
bp->SetDomain(0, -100.0, 100.0);
bp->SetDomain(1, -100.0, 100.0);
bp->SetExtents(0, bp->Domain(0));
bp->SetExtents(1, bp->Domain(1));
(*b)->m_S.Append(bp);
const int bsi = (*b)->m_S.Count() - 1;
ON_BrepFace& bface = (*b)->NewFace(bsi);
(*b)->NewPlanarFaceLoop(bface.m_face_index, ON_BrepLoop::outer, boundary, true);
const ON_BrepLoop* bloop = (*b)->m_L.Last();
bp->SetDomain(0, bloop->m_pbox.m_min.x, bloop->m_pbox.m_max.x);
bp->SetDomain(1, bloop->m_pbox.m_min.y, bloop->m_pbox.m_max.y);
bp->SetExtents(0, bp->Domain(0));
bp->SetExtents(1, bp->Domain(1));
(*b)->FlipFace(bface);
(*b)->SetTrimIsoFlags(bface);
boundary.Empty();
delete bcurve;
// Generate the top cap
boundary.Append(ON_Curve::Cast(tcurve));
ON_PlaneSurface* tp = new ON_PlaneSurface();
tp->m_plane = hyp_top_plane;
tp->SetDomain(0, -100.0, 100.0);
tp->SetDomain(1, -100.0, 100.0);
tp->SetExtents(0, bp->Domain(0));
tp->SetExtents(1, bp->Domain(1));
(*b)->m_S.Append(tp);
int tsi = (*b)->m_S.Count() - 1;
ON_BrepFace& tface = (*b)->NewFace(tsi);
(*b)->NewPlanarFaceLoop(tface.m_face_index, ON_BrepLoop::outer, boundary, true);
ON_BrepLoop* tloop = (*b)->m_L.Last();
tp->SetDomain(0, tloop->m_pbox.m_min.x, tloop->m_pbox.m_max.x);
tp->SetDomain(1, tloop->m_pbox.m_min.y, tloop->m_pbox.m_max.y);
tp->SetExtents(0, bp->Domain(0));
tp->SetExtents(1, bp->Domain(1));
(*b)->SetTrimIsoFlags(tface);
delete tcurve;
// Now, the hard part. Need an elliptical hyperbolic NURBS surface.
// First step is to create a nurbs curve.
double MX = eip->hyp_b * eip->hyp_bnr;
point_t ep1, ep2, ep3;
VSET(ep1, -eip->hyp_b, 0, 0.5*MAGNITUDE(eip->hyp_Hi));
VSET(ep2, -MX*eip->hyp_bnr, 0, 0);
VSET(ep3, -eip->hyp_b, 0, -0.5*MAGNITUDE(eip->hyp_Hi));
ON_3dPoint onp1 = ON_3dPoint(ep1);
ON_3dPoint onp2 = ON_3dPoint(ep2);
ON_3dPoint onp3 = ON_3dPoint(ep3);
ON_3dPointArray cpts(3);
cpts.Append(onp1);
cpts.Append(onp2);
cpts.Append(onp3);
ON_BezierCurve *bezcurve = new ON_BezierCurve(cpts);
bezcurve->MakeRational();
bezcurve->SetWeight(1, bezcurve->Weight(0)/eip->hyp_bnr);
ON_NurbsCurve* tnurbscurve = ON_NurbsCurve::New();
bezcurve->GetNurbForm(*tnurbscurve);
delete bezcurve;
ON_3dPoint revpnt1 = ON_3dPoint(0, 0, -0.5*MAGNITUDE(eip->hyp_Hi));
ON_3dPoint revpnt2 = ON_3dPoint(0, 0, 0.5*MAGNITUDE(eip->hyp_Hi));
ON_Line revaxis = ON_Line(revpnt1, revpnt2);
ON_RevSurface* hyp_surf = ON_RevSurface::New();
hyp_surf->m_curve = tnurbscurve;
hyp_surf->m_axis = revaxis;
hyp_surf->m_angle = ON_Interval(0, 2*ON_PI);
// Get the NURBS form of the surface
ON_NurbsSurface *hypcurvedsurf = ON_NurbsSurface::New();
hyp_surf->GetNurbForm(*hypcurvedsurf, 0.0);
delete hyp_surf;
for (int i = 0; i < hypcurvedsurf->CVCount(0); i++) {
for (int j = 0; j < hypcurvedsurf->CVCount(1); j++) {
point_t cvpt;
ON_4dPoint ctrlpt;
hypcurvedsurf->GetCV(i, j, ctrlpt);
// Scale and shear
vect_t proj_ah;
vect_t proj_ax;
fastf_t factor;
VPROJECT(eip->hyp_A, eip->hyp_Hi, proj_ah, proj_ax);
VSET(cvpt, ctrlpt.x * MAGNITUDE(proj_ax)/eip->hyp_b, ctrlpt.y, ctrlpt.z);
factor = VDOT(eip->hyp_A, eip->hyp_Hi)>0 ? 1.0 : -1.0;
cvpt[2] += factor*cvpt[0]/MAGNITUDE(proj_ax)*MAGNITUDE(proj_ah) + 0.5*MAGNITUDE(eip->hyp_Hi)*ctrlpt.w;
// Rotate
vect_t Au, Bu, Hu;
mat_t R;
point_t new_cvpt;
VSCALE(Bu, y_dir, 1/MAGNITUDE(y_dir));
VSCALE(Hu, eip->hyp_Hi, 1/MAGNITUDE(eip->hyp_Hi));
VCROSS(Au, Bu, Hu);
VUNITIZE(Au);
MAT_IDN(R);
VMOVE(&R[0], Au);
VMOVE(&R[4], Bu);
VMOVE(&R[8], Hu);
VEC3X3MAT(new_cvpt, cvpt, R);
VMOVE(cvpt, new_cvpt);
// Translate
vect_t scale_v;
VSCALE(scale_v, eip->hyp_Vi, ctrlpt.w);
VADD2(cvpt, cvpt, scale_v);
ON_4dPoint newpt = ON_4dPoint(cvpt[0], cvpt[1], cvpt[2], ctrlpt.w);
hypcurvedsurf->SetCV(i, j, newpt);
}
}
(*b)->m_S.Append(hypcurvedsurf);
int surfindex = (*b)->m_S.Count();
ON_BrepFace& face = (*b)->NewFace(surfindex - 1);
(*b)->FlipFace(face);
int faceindex = (*b)->m_F.Count();
(*b)->NewOuterLoop(faceindex-1);
}
