bool ON_PolyEdgeCurve::EvSrfTangent(
double t,
bool bIsoDir,
ON_3dPoint& srfpoint,
ON_3dVector& srftangent,
ON_3dVector& srfnormal
) const
{
ON_3dPoint srfpt;
ON_3dVector du, dv, duu, duv, dvv;
bool rc = EvSrfDerivatives(t,srfpoint,du,dv,duu,duv,dvv);
if (rc )
rc = ON_EvNormal( 0, du, dv, duu, duv, dvv, srfnormal ) ? true : false;
if (rc)
{
int segment_index = SegmentIndex(t);
ON_PolyEdgeSegment* seg = SegmentCurve(segment_index);
if ( seg )
{
if ( bIsoDir && seg->IsoType() == ON_Surface::not_iso )
bIsoDir = false;
ON_3dVector crvtangent = TangentAt(t);
ON_3dVector binormal = ON_CrossProduct(crvtangent,srfnormal);
binormal.Unitize();
if ( seg->ReversedTrimDir() )
binormal.Reverse();
// at this point, binormal points "out" and is tangent
// to the surface.
if ( bIsoDir )
{
du.Unitize();
dv.Unitize();
double B_dot_du = binormal*du;
double B_dot_dv = binormal*dv;
if ( fabs(B_dot_dv) > fabs(B_dot_du) )
{
if (B_dot_dv < 0.0)
dv.Reverse();
srftangent = dv;
}
else
{
if (B_dot_du < 0.0)
du.Reverse();
srftangent = du;
}
}
else
srftangent = binormal;
if ( seg && seg->m_face && seg->m_face->m_bRev )
srfnormal.Reverse();
}
else
rc = false;
}
return rc;
}
ON_2dPoint ON_PolyEdgeCurve::SurfaceParameter(double t) const
{
ON_2dPoint srf_uv(ON_UNSET_VALUE,ON_UNSET_VALUE);
int segment_index = SegmentIndex(t);
ON_PolyEdgeSegment* seg = SegmentCurve( segment_index );
if ( seg )
{
ON_Interval pdom = SegmentDomain(segment_index);
ON_Interval sdom = seg->Domain();
if ( sdom != pdom )
{
double s = pdom.NormalizedParameterAt(t);
t = sdom.ParameterAt(s);
}
srf_uv = seg->SurfaceParameter(t);
}
return srf_uv;
}
double ON_PolyEdgeCurve::TrimParameter(double t) const
{
double trim_t = ON_UNSET_VALUE;
int segment_index = SegmentIndex(t);
ON_PolyEdgeSegment* seg = SegmentCurve( segment_index );
if ( seg )
{
ON_Interval pdom = SegmentDomain(segment_index);
ON_Interval sdom = seg->Domain();
if ( sdom != pdom )
{
double s = pdom.NormalizedParameterAt(t);
t = sdom.ParameterAt(s);
}
trim_t = seg->TrimParameter(t);
}
return trim_t;
}
template <> DLL_HEADER Ng_Element Ng_GetElement<1> (int nr)
{
const Segment & el = mesh->LineSegment (SegmentIndex(nr));
Ng_Element ret;
ret.type = NG_ELEMENT_TYPE(el.GetType());
ret.points.num = el.GetNP();
ret.points.ptr = (int*)&(el[0]);
ret.vertices.num = 2;
ret.vertices.ptr = (int*)&(el[0]);
ret.edges.num = 1;
ret.edges.ptr = mesh->GetTopology().GetSegmentElementEdgesPtr (nr);
ret.faces.num = 0;
ret.faces.ptr = NULL;
return ret;
}
NGX_INLINE DLL_HEADER Ng_Element Ngx_Mesh :: GetElement<1> (int nr) const
{
const Segment & el = mesh->LineSegment (SegmentIndex(nr));
Ng_Element ret;
ret.type = NG_ELEMENT_TYPE(el.GetType());
ret.index = el.si;
ret.points.num = el.GetNP();
ret.points.ptr = (int*)&(el[0]);
ret.vertices.num = 2;
ret.vertices.ptr = (int*)&(el[0]);
ret.edges.num = 1;
ret.edges.ptr = (T_EDGE2*)mesh->GetTopology().GetSegmentElementEdgesPtr (nr);
ret.faces.num = 0;
ret.faces.ptr = NULL;
return ret;
}
NGX_INLINE DLL_HEADER int Ngx_Mesh :: GetElementIndex<1> (int nr) const
{
return (*mesh)[SegmentIndex(nr)].si;
}
DLL_HEADER int Ng_GetElementIndex<1> (int nr)
{
return (*mesh)[SegmentIndex(nr)].si;
}
ON_Surface::ISO ON_PolyEdgeCurve::IsoType( double t) const
{
ON_PolyEdgeSegment* seg = SegmentCurve( SegmentIndex(t) );
return seg ? seg->IsoType() : ON_Surface::not_iso;
}
const ON_Surface* ON_PolyEdgeCurve::SurfaceAt(double t) const
{
ON_PolyEdgeSegment* seg = SegmentCurve( SegmentIndex(t) );
return seg ? seg->Surface() : 0;
}
const ON_Brep* ON_PolyEdgeCurve::BrepAt(double t) const
{
ON_PolyEdgeSegment* seg = SegmentCurve( SegmentIndex(t) );
return seg ? seg->Brep() : 0;
}
const ON_BrepTrim* ON_PolyEdgeCurve::TrimAt(double t) const
{
ON_PolyEdgeSegment* seg = SegmentCurve( SegmentIndex(t) );
return seg ? seg->Trim() : 0;
}
const ON_BrepEdge* ON_PolyEdgeCurve::EdgeAt(double t) const
{
ON_PolyEdgeSegment* seg = SegmentCurve( SegmentIndex(t) );
return seg ? seg->Edge() : 0;
}
bool ON_PolyEdgeCurve::EvSrfDerivatives(
double t,
ON_3dPoint& srfpoint,
ON_3dVector& du,
ON_3dVector& dv,
ON_3dVector& duu,
ON_3dVector& duv,
ON_3dVector& dvv
) const
{
bool rc = false;
int segment_index = SegmentIndex(t);
ON_PolyEdgeSegment* seg = SegmentCurve( segment_index );
if ( seg )
{
ON_Interval pdom = SegmentDomain(segment_index);
ON_Interval sdom = seg->Domain();
double s = t;
if ( sdom != pdom )
{
double x = pdom.NormalizedParameterAt(t);
s = sdom.ParameterAt(x);
}
// s is the segment parameter at the polyedge parameter t
// Get the corresponding surfaces parameters
ON_2dPoint srf_uv = seg->SurfaceParameter(s);
if ( ON_IsValid(srf_uv.x) )
{
if ( srf_uv.x == seg->m_evsrf_uv[0] && srf_uv.y == seg->m_evsrf_uv[1] )
{
rc = true;
srfpoint = seg->m_evsrf_pt;
du = seg->m_evsrf_du;
dv = seg->m_evsrf_dv;
duu = seg->m_evsrf_duu;
duv = seg->m_evsrf_duv;
dvv = seg->m_evsrf_dvv;
}
else if ( seg->m_surface )
{
rc = seg->m_surface->Ev2Der(
srf_uv.x, srf_uv.y,
srfpoint,
du, dv,
duu, duv, dvv,
0, seg->m_evsrf_hint
) ? true : false;
if ( rc )
{
CookDerivativesHelper( du, dv, duu, duv, dvv);
seg->m_evsrf_uv[0] = srf_uv.x;
seg->m_evsrf_uv[1] = srf_uv.y;
seg->m_evsrf_pt = srfpoint;
seg->m_evsrf_du = du;
seg->m_evsrf_dv = dv;
seg->m_evsrf_duu = duu;
seg->m_evsrf_duv = duv;
seg->m_evsrf_dvv = dvv;
}
}
}
}
return rc;
}