//----------------------------------------------------------------------------
void CIsoSurface::GetZMaxEdges (int iX, int iY, int iZ, int iType,
VETable& rkTable)
{
int iFaceType = 0;
if ( iType & EB_XMIN_ZMAX ) iFaceType |= 0x01;
if ( iType & EB_XMAX_ZMAX ) iFaceType |= 0x02;
if ( iType & EB_YMIN_ZMAX ) iFaceType |= 0x04;
if ( iType & EB_YMAX_ZMAX ) iFaceType |= 0x08;
switch ( iFaceType )
{
case 0: return;
case 3: rkTable.Insert(EI_XMIN_ZMAX,EI_XMAX_ZMAX); break;
case 5: rkTable.Insert(EI_XMIN_ZMAX,EI_YMIN_ZMAX); break;
case 6: rkTable.Insert(EI_XMAX_ZMAX,EI_YMIN_ZMAX); break;
case 9: rkTable.Insert(EI_XMIN_ZMAX,EI_YMAX_ZMAX); break;
case 10: rkTable.Insert(EI_XMAX_ZMAX,EI_YMAX_ZMAX); break;
case 12: rkTable.Insert(EI_YMIN_ZMAX,EI_YMAX_ZMAX); break;
case 15:
{
// four vertices, one per edge, need to disambiguate
int i = iX + m_iXBound*(iY + m_iYBound*(iZ+1));
int iF00 = m_aiData[i]; // F(x,y,z)
i++;
int iF10 = m_aiData[i]; // F(x+1,y,z)
i += m_iXBound;
int iF11 = m_aiData[i]; // F(x+1,y+1,z)
i--;
int iF01 = m_aiData[i]; // F(x,y+1,z)
int iDet = iF00*iF11 - iF01*iF10;
if ( iDet > 0 )
{
// disjoint hyperbolic segments, pair <P0,P2>, <P1,P3>
rkTable.Insert(EI_XMIN_ZMAX,EI_YMIN_ZMAX);
rkTable.Insert(EI_XMAX_ZMAX,EI_YMAX_ZMAX);
}
else if ( iDet < 0 )
{
// disjoint hyperbolic segments, pair <P0,P3>, <P1,P2>
rkTable.Insert(EI_XMIN_ZMAX,EI_YMAX_ZMAX);
rkTable.Insert(EI_XMAX_ZMAX,EI_YMIN_ZMAX);
}
else
{
// plus-sign configuration, add branch point to tessellation
rkTable.Insert(FI_ZMAX,TVector3D(rkTable.GetX(EI_YMIN_ZMAX),
rkTable.GetY(EI_XMIN_ZMAX),rkTable.GetZ(EI_XMIN_ZMAX)));
// add edges sharing the branch point
rkTable.Insert(EI_XMIN_ZMAX,FI_ZMAX);
rkTable.Insert(EI_XMAX_ZMAX,FI_ZMAX);
rkTable.Insert(EI_YMIN_ZMAX,FI_ZMAX);
rkTable.Insert(EI_YMAX_ZMAX,FI_ZMAX);
}
break;
}
default: assert( false );
}
}
//----------------------------------------------------------------------------
int CIsoSurface::GetVertices (float fLevel, int iX, int iY, int iZ,
VETable& rkTable)
{
int iType = 0;
// get image values at corners of voxel
int i000 = iX + m_iXBound*(iY + m_iYBound*iZ);
int i100 = i000 + 1;
int i010 = i000 + m_iXBound;
int i110 = i010 + 1;
int i001 = i000 + m_iXYBound;
int i101 = i001 + 1;
int i011 = i001 + m_iXBound;
int i111 = i011 + 1;
float fF000 = (float)m_aiData[i000];
float fF100 = (float)m_aiData[i100];
float fF010 = (float)m_aiData[i010];
float fF110 = (float)m_aiData[i110];
float fF001 = (float)m_aiData[i001];
float fF101 = (float)m_aiData[i101];
float fF011 = (float)m_aiData[i011];
float fF111 = (float)m_aiData[i111];
float fX0 = (float)iX, fY0 = (float)iY, fZ0 = (float)iZ;
float fX1 = fX0+1.0f, fY1 = fY0+1.0f, fZ1 = fZ0+1.0f;
// xmin-ymin edge
float fDiff0 = fLevel - fF000;
float fDiff1 = fLevel - fF001;
if ( fDiff0*fDiff1 < 0.0f )
{
iType |= EB_XMIN_YMIN;
rkTable.Insert(EI_XMIN_YMIN,
TVector3D(fX0,fY0,fZ0+fDiff0/(fF001-fF000)));
}
// xmin-ymax edge
fDiff0 = fLevel - fF010;
fDiff1 = fLevel - fF011;
if ( fDiff0*fDiff1 < 0.0f )
{
iType |= EB_XMIN_YMAX;
rkTable.Insert(EI_XMIN_YMAX,
TVector3D(fX0,fY1,fZ0+fDiff0/(fF011-fF010)));
}
// xmax-ymin edge
fDiff0 = fLevel - fF100;
fDiff1 = fLevel - fF101;
if ( fDiff0*fDiff1 < 0.0f )
{
iType |= EB_XMAX_YMIN;
rkTable.Insert(EI_XMAX_YMIN,
TVector3D(fX1,fY0,fZ0+fDiff0/(fF101-fF100)));
}
// xmax-ymax edge
fDiff0 = fLevel - fF110;
fDiff1 = fLevel - fF111;
if ( fDiff0*fDiff1 < 0.0f )
{
iType |= EB_XMAX_YMAX;
rkTable.Insert(EI_XMAX_YMAX,
TVector3D(fX1,fY1,fZ0+fDiff0/(fF111-fF110)));
}
// xmin-zmin edge
fDiff0 = fLevel - fF000;
fDiff1 = fLevel - fF010;
if ( fDiff0*fDiff1 < 0.0f )
{
iType |= EB_XMIN_ZMIN;
rkTable.Insert(EI_XMIN_ZMIN,
TVector3D(fX0,fY0+fDiff0/(fF010-fF000),fZ0));
}
// xmin-zmax edge
fDiff0 = fLevel - fF001;
fDiff1 = fLevel - fF011;
if ( fDiff0*fDiff1 < 0.0f )
{
iType |= EB_XMIN_ZMAX;
rkTable.Insert(EI_XMIN_ZMAX,
TVector3D(fX0,fY0+fDiff0/(fF011-fF001),fZ1));
}
// xmax-zmin edge
fDiff0 = fLevel - fF100;
fDiff1 = fLevel - fF110;
if ( fDiff0*fDiff1 < 0.0f )
{
iType |= EB_XMAX_ZMIN;
rkTable.Insert(EI_XMAX_ZMIN,
TVector3D(fX1,fY0+fDiff0/(fF110-fF100),fZ0));
}
// xmax-zmax edge
fDiff0 = fLevel - fF101;
fDiff1 = fLevel - fF111;
if ( fDiff0*fDiff1 < 0.0f )
{
iType |= EB_XMAX_ZMAX;
rkTable.Insert(EI_XMAX_ZMAX,
TVector3D(fX1,fY0+fDiff0/(fF111-fF101),fZ1));
}
// ymin-zmin edge
fDiff0 = fLevel - fF000;
fDiff1 = fLevel - fF100;
if ( fDiff0*fDiff1 < 0.0f )
{
iType |= EB_YMIN_ZMIN;
rkTable.Insert(EI_YMIN_ZMIN,
TVector3D(fX0+fDiff0/(fF100-fF000),fY0,fZ0));
}
// ymin-zmax edge
fDiff0 = fLevel - fF001;
fDiff1 = fLevel - fF101;
if ( fDiff0*fDiff1 < 0.0f )
{
iType |= EB_YMIN_ZMAX;
rkTable.Insert(EI_YMIN_ZMAX,
TVector3D(fX0+fDiff0/(fF101-fF001),fY0,fZ1));
}
// ymax-zmin edge
fDiff0 = fLevel - fF010;
fDiff1 = fLevel - fF110;
if ( fDiff0*fDiff1 < 0.0f )
{
iType |= EB_YMAX_ZMIN;
rkTable.Insert(EI_YMAX_ZMIN,
TVector3D(fX0+fDiff0/(fF110-fF010),fY1,fZ0));
}
// ymax-zmax edge
fDiff0 = fLevel - fF011;
fDiff1 = fLevel - fF111;
if ( fDiff0*fDiff1 < 0.0f )
{
iType |= EB_YMAX_ZMAX;
rkTable.Insert(EI_YMAX_ZMAX,
TVector3D(fX0+fDiff0/(fF111-fF011),fY1,fZ1));
}
return iType;
}
/*!
Returns the 3D vector form of this 4D vector, dividing the x, y, and
z coordinates by the w coordinate. Returns a null vector if w is zero.
\sa toVector3D(), toVector2DAffine(), toPoint()
*/
TVector3D TVector4D::toVector3DAffine() const
{
if (qIsNull(wp))
return TVector3D();
return TVector3D(xp / wp, yp / wp, zp / wp, 1);
}
/*!
Returns the 3D form of this 2D vector, with the z coordinate set to zero.
\sa toVector4D(), toPoint()
*/
TVector3D TVector2D::toVector3D() const
{
return TVector3D(xp, yp, 0.0f, 1);
}
/*!
Returns the 3D vector form of this 4D vector, dropping the w coordinate.
\sa toVector3DAffine(), toVector2D(), toPoint()
*/
TVector3D TVector4D::toVector3D() const
{
return TVector3D(xp, yp, zp, 1);
}
