//----------------------------------------------------------------------------
bool Mgc::FindIntersection (const Segment3& rkSegment, const Box3& rkBox,
int& riQuantity, Vector3 akPoint[2])
{
// convert segment to box coordinates
Vector3 kDiff = rkSegment.Origin() - rkBox.Center();
Vector3 kOrigin(
kDiff.Dot(rkBox.Axis(0)),
kDiff.Dot(rkBox.Axis(1)),
kDiff.Dot(rkBox.Axis(2))
);
Vector3 kDirection(
rkSegment.Direction().Dot(rkBox.Axis(0)),
rkSegment.Direction().Dot(rkBox.Axis(1)),
rkSegment.Direction().Dot(rkBox.Axis(2))
);
Real fT0 = 0.0f, fT1 = 1.0f;
bool bIntersects = FindIntersection(kOrigin,kDirection,rkBox.Extents(),
fT0,fT1);
if ( bIntersects )
{
if ( fT0 > 0.0f )
{
if ( fT1 < 1.0f )
{
riQuantity = 2;
akPoint[0] = rkSegment.Origin() + fT0*rkSegment.Direction();
akPoint[1] = rkSegment.Origin() + fT1*rkSegment.Direction();
}
else
{
riQuantity = 1;
akPoint[0] = rkSegment.Origin() + fT0*rkSegment.Direction();
}
}
else // fT0 == 0
{
if ( fT1 < 1.0f )
{
riQuantity = 1;
akPoint[0] = rkSegment.Origin() + fT1*rkSegment.Direction();
}
else // fT1 == 1
{
// segment entirely in box
riQuantity = 0;
}
}
}
else
{
riQuantity = 0;
}
return bIntersects;
}
Box3<Real> Wml::ContOrientedBox (int iQuantity, const Vector3<Real>* akPoint)
{
Box3<Real> kBox;
GaussPointsFit(iQuantity,akPoint,kBox.Center(),kBox.Axes(),
kBox.Extents());
// Let C be the box center and let U0, U1, and U2 be the box axes. Each
// input point is of the form X = C + y0*U0 + y1*U1 + y2*U2. The
// following code computes min(y0), max(y0), min(y1), max(y1), min(y2),
// and max(y2). The box center is then adjusted to be
// C' = C + 0.5*(min(y0)+max(y0))*U0 + 0.5*(min(y1)+max(y1))*U1 +
// 0.5*(min(y2)+max(y2))*U2
Vector3<Real> kDiff = akPoint[0] - kBox.Center();
Real fY0Min = kDiff.Dot(kBox.Axis(0)), fY0Max = fY0Min;
Real fY1Min = kDiff.Dot(kBox.Axis(1)), fY1Max = fY1Min;
Real fY2Min = kDiff.Dot(kBox.Axis(2)), fY2Max = fY2Min;
for (int i = 1; i < iQuantity; i++)
{
kDiff = akPoint[i] - kBox.Center();
Real fY0 = kDiff.Dot(kBox.Axis(0));
if ( fY0 < fY0Min )
fY0Min = fY0;
else if ( fY0 > fY0Max )
fY0Max = fY0;
Real fY1 = kDiff.Dot(kBox.Axis(1));
if ( fY1 < fY1Min )
fY1Min = fY1;
else if ( fY1 > fY1Max )
fY1Max = fY1;
Real fY2 = kDiff.Dot(kBox.Axis(2));
if ( fY2 < fY2Min )
fY2Min = fY2;
else if ( fY2 > fY2Max )
fY2Max = fY2;
}
kBox.Center() += (((Real)0.5)*(fY0Min+fY0Max))*kBox.Axis(0) +
(((Real)0.5)*(fY1Min+fY1Max))*kBox.Axis(1) +
(((Real)0.5)*(fY2Min+fY2Max))*kBox.Axis(2);
kBox.Extent(0) = ((Real)0.5)*(fY0Max - fY0Min);
kBox.Extent(1) = ((Real)0.5)*(fY1Max - fY1Min);
kBox.Extent(2) = ((Real)0.5)*(fY2Max - fY2Min);
return kBox;
}
//----------------------------------------------------------------------------
bool Mgc::FindIntersection (const Line3& rkLine, const Box3& rkBox,
int& riQuantity, Vector3 akPoint[2])
{
// convert line to box coordinates
Vector3 kDiff = rkLine.Origin() - rkBox.Center();
Vector3 kOrigin(
kDiff.Dot(rkBox.Axis(0)),
kDiff.Dot(rkBox.Axis(1)),
kDiff.Dot(rkBox.Axis(2))
);
Vector3 kDirection(
rkLine.Direction().Dot(rkBox.Axis(0)),
rkLine.Direction().Dot(rkBox.Axis(1)),
rkLine.Direction().Dot(rkBox.Axis(2))
);
Real fT0 = -Math::MAX_REAL, fT1 = Math::MAX_REAL;
bool bIntersects = FindIntersection(kOrigin,kDirection,rkBox.Extents(),
fT0,fT1);
if ( bIntersects )
{
if ( fT0 != fT1 )
{
riQuantity = 2;
akPoint[0] = rkLine.Origin() + fT0*rkLine.Direction();
akPoint[1] = rkLine.Origin() + fT1*rkLine.Direction();
}
else
{
riQuantity = 1;
akPoint[0] = rkLine.Origin() + fT0*rkLine.Direction();
}
}
else
{
riQuantity = 0;
}
return bIntersects;
}
bool Wml::ContOrientedBox (int iQuantity, const Vector3<Real>* akPoint,
const bool* abValid, Box3<Real>& rkBox)
{
if ( !GaussPointsFit(iQuantity,akPoint,abValid,rkBox.Center(),
rkBox.Axes(),rkBox.Extents()) )
{
return false;
}
// Let C be the box center and let U0, U1, and U2 be the box axes. Each
// input point is of the form X = C + y0*U0 + y1*U1 + y2*U2. The
// following code computes min(y0), max(y0), min(y1), max(y1), min(y2),
// and max(y2). The box center is then adjusted to be
// C' = C + 0.5*(min(y0)+max(y0))*U0 + 0.5*(min(y1)+max(y1))*U1 +
// 0.5*(min(y2)+max(y2))*U2
// get first valid vertex
Vector3<Real> kDiff;
Real fY0Min = (Real)0.0, fY0Max = (Real)0.0;
Real fY1Min = (Real)0.0, fY1Max = (Real)0.0;
Real fY2Min = (Real)0.0, fY2Max = (Real)0.0;
int i;
for (i = 0; i < iQuantity; i++)
{
if ( abValid[i] )
{
kDiff = akPoint[i] - rkBox.Center();
fY0Min = kDiff.Dot(rkBox.Axis(0));
fY0Max = fY0Min;
fY1Min = kDiff.Dot(rkBox.Axis(1));
fY1Max = fY1Min;
fY2Min = kDiff.Dot(rkBox.Axis(2));
fY2Max = fY2Min;
break;
}
}
for (i++; i < iQuantity; i++)
{
if ( abValid[i] )
{
kDiff = akPoint[i] - rkBox.Center();
Real fY0 = kDiff.Dot(rkBox.Axis(0));
if ( fY0 < fY0Min )
fY0Min = fY0;
else if ( fY0 > fY0Max )
fY0Max = fY0;
Real fY1 = kDiff.Dot(rkBox.Axis(1));
if ( fY1 < fY1Min )
fY1Min = fY1;
else if ( fY1 > fY1Max )
fY1Max = fY1;
Real fY2 = kDiff.Dot(rkBox.Axis(2));
if ( fY2 < fY2Min )
fY2Min = fY2;
else if ( fY2 > fY2Max )
fY2Max = fY2;
}
}
rkBox.Center() += (0.5f*(fY0Min+fY0Max))*rkBox.Axis(0)
+ (0.5f*(fY1Min+fY1Max))*rkBox.Axis(1) +
(0.5f*(fY2Min+fY2Max))*rkBox.Axis(2);
rkBox.Extent(0) = 0.5f*(fY0Max - fY0Min);
rkBox.Extent(1) = 0.5f*(fY1Max - fY1Min);
rkBox.Extent(2) = 0.5f*(fY2Max - fY2Min);
return true;
}
