//两点在直线同一边(vP1,vP2在A,B同一边)
Bool HawkTriangle3D::IsOnSameSide(const HawkVector3D& vP1,const HawkVector3D& vP2,const HawkVector3D& vA, const HawkVector3D& vB)
{
HawkVector3D bminusa = vB - vA;
HawkVector3D cp1 = bminusa.CrossProduct(vP1 - vA);
HawkVector3D cp2 = bminusa.CrossProduct(vP2 - vA);
return (cp1.DotProduct(cp2) >= 0.0f);
}
//////////////////////////////////////////////////////////////////////////
//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;
}