void HawkTriangle3D::GetProjection (const HawkVector3D& vAxis,Float& fMin, Float& fMax) const
{
Float dot[3] =
{
vAxis.DotProduct(GetPoint(0)),
vAxis.DotProduct(GetPoint(1)),
vAxis.DotProduct(GetPoint(2))
};
fMin = dot[0];
fMax = fMin;
if (dot[1] < fMin)
{
fMin = dot[1];
}
else if (dot[1] > fMax)
{
fMax = dot[1];
}
if (dot[2] < fMin)
{
fMin = dot[2];
}
else if (dot[2] > fMax)
{
fMax = dot[2];
}
}
Bool HawkLine3D::Intersect(const HawkOBB& oBox,Vec3IntrResult* pResult) const
{
const HawkVector3D* Axis = oBox.GetAxis();
HawkVector3D diff = Point - oBox.Center;
HawkVector3D BOrigin(
diff.DotProduct(Axis[0]),
diff.DotProduct(Axis[1]),
diff.DotProduct(Axis[2])
);
HawkVector3D BDirection(
Direction.DotProduct(Axis[0]),
Direction.DotProduct(Axis[1]),
Direction.DotProduct(Axis[2])
);
Float t0 = -FLT_MAX,t1 = FLT_MAX;
bool notAllClipped =
geoClip(+BDirection.X, -BOrigin.X-oBox.Extent[0], t0, t1) &&
geoClip(-BDirection.X, +BOrigin.X-oBox.Extent[0], t0, t1) &&
geoClip(+BDirection.Y, -BOrigin.Y-oBox.Extent[1], t0, t1) &&
geoClip(-BDirection.Y, +BOrigin.Y-oBox.Extent[1], t0, t1) &&
geoClip(+BDirection.Z, -BOrigin.Z-oBox.Extent[2], t0, t1) &&
geoClip(-BDirection.Z, +BOrigin.Z-oBox.Extent[2], t0, t1);
if (notAllClipped)
{
//2交点
if (t1 > t0)
{
if (pResult)
{
pResult->Factor = HawkMath::Abs<Float>(t0) < HawkMath::Abs<Float>(t1)? t0 : t1;
pResult->Point = Point + Direction * pResult->Factor;
}
return true;
}
//1交点
else
{
if (pResult)
{
pResult->Factor = t0;
pResult->Point = Point + Direction * pResult->Factor;
}
return true;
}
}
return false;
}
//直线和球相交
Bool HawkLine3D::Intersect(const HawkSphere& oSphere,Vec3IntrResult* pResult) const
{
HawkVector3D vDiff = Point - oSphere.Center;
Float a0 = vDiff.DotProduct(vDiff) - oSphere.Radius*oSphere.Radius;
Float a1 = Direction.DotProduct(vDiff);
Float dis = a1*a1 - a0;
if (dis >= 0)
{
if (pResult)
{
if (dis >= HawkMath::FLOAT_DIFF)
{
Float root = HawkMath::Sqrt(dis);
Float t0 = -a1 - root;
Float t1 = -a1 + root;
pResult->Factor = HawkMath::Abs<Float>(t0) < HawkMath::Abs<Float>(t1)?t0:t1;
pResult->Point = Point + pResult->Factor*Direction;
}
else
{
Float t0 = -a1;
pResult->Factor = t0;
pResult->Point = Point + t0*Direction;
}
}
return true;
}
return false;
}
//////////////////////////////////////////////////////////////////////////
//直线和三角形相交
Bool HawkLine3D::Intersect(const HawkTriangle3D& oTriangle,Vec3IntrResult* pResult) const
{
HawkVector3D vDiff = Point - oTriangle.GetPoint(0);
HawkVector3D edge1 = oTriangle.GetEdge(0);
HawkVector3D edge2 = oTriangle.GetEdge(1);
HawkVector3D normal = edge1.CrossProduct(edge2);
Float DdN = Direction.DotProduct(normal);
Float fSign = 0.0f;
if (DdN > HawkMath::FLOAT_DIFF)
{
fSign = 1.0f;
}
else if (DdN < -HawkMath::FLOAT_DIFF)
{
fSign = -1.0f;
DdN = -DdN;
}
else
{
return false;
}
Float DdQxE2 = fSign*Direction.DotProduct(vDiff.CrossProduct(edge2));
if (DdQxE2 >= 0.0f)
{
Float DdE1xQ = fSign*Direction.DotProduct(edge1.CrossProduct(vDiff));
if (DdE1xQ >= 0.0f)
{
if (DdQxE2 + DdE1xQ <= DdN)
{
if (pResult)
{
Float QdN = -fSign*vDiff.DotProduct(normal);
pResult->Factor = QdN / DdN;
pResult->Point = Point + pResult->Factor*Direction;
}
return true;
}
}
}
return false;
}
//计算线段上面和oVec相隔最近的点
HawkVector3D HawkLine3D::GetClosestPoint(const HawkVector3D& oVec) const
{
HawkVector3D oTmp = oVec - Point;
return Point + Direction*oTmp.DotProduct(Direction);
}
Bool HawkTriangle3D::IsFrontFacing(const HawkVector3D& vVec3) const
{
HawkVector3D vNormal = GetNormal();
Float fDis = vNormal.DotProduct(vVec3);
return fDis >= 0.0f;
}