//===========================================================================
void cLight::setDir(const cVector3d& a_direction)
{
// We arbitrarily point lights along the x axis of the stored
// rotation matrix... this allows matrix transformations
// to apply to lights.
// m_localRot.setCol0(a_direction);
cVector3d c0, c1, c2, t;
a_direction.copyto(c0);
// check vector
if (c0.lengthsq() < 0.0001) { return; }
// normalize direction vector
c0.normalize();
// compute 2 vector perpendicular to a_direction
t.set(a_direction.y, a_direction.z, a_direction.x);
t.crossr(c0, c1);
c1.crossr(c0, c2);
// c0.negate();
c1.negate();
c2.negate();
// update rotation matrix
m_localRot.setCol(c0,c1,c2);
}
//===========================================================================
void cDirectionalLight::setDir(const cVector3d& a_direction)
{
// We arbitrarily point lights along the x axis of the stored
// rotation matrix... this allows matrix transformations
// to apply to lights.
// m_localRot.setCol0(a_direction);
cVector3d c0, c1, c2, t0, t1;
a_direction.copyto(c0);
// check vector
if (c0.lengthsq() < 0.0001) {
return;
}
// normalize direction vector
c0.normalize();
// compute 2 vector perpendicular to a_direction
t0.set(0.0, 0.0, 1.0);
t1.set(0.0, 1.0, 0.0);
double a0 = cAngle(c0, t0);
double a1 = cAngle(c0, t1);
if (sin(a0) > sin(a1))
{
c0.crossr(t0, c1);
c0.crossr(c1, c2);
}
else
{
c0.crossr(t1, c1);
c0.crossr(c1, c2);
}
c1.normalize();
c2.normalize();
// update rotation matrix
m_localRot.setCol(c0,c1,c2);
}
