// static
Matrix4f Matrix4f::rotation( const Quat4f& q )
{
Quat4f qq = q.normalized();
float xx = qq.x() * qq.x();
float yy = qq.y() * qq.y();
float zz = qq.z() * qq.z();
float xy = qq.x() * qq.y();
float zw = qq.z() * qq.w();
float xz = qq.x() * qq.z();
float yw = qq.y() * qq.w();
float yz = qq.y() * qq.z();
float xw = qq.x() * qq.w();
return Matrix4f
(
1.0f - 2.0f * ( yy + zz ), 2.0f * ( xy - zw ), 2.0f * ( xz + yw ), 0.0f,
2.0f * ( xy + zw ), 1.0f - 2.0f * ( xx + zz ), 2.0f * ( yz - xw ), 0.0f,
2.0f * ( xz - yw ), 2.0f * ( yz + xw ), 1.0f - 2.0f * ( xx + yy ), 0.0f,
0.0f, 0.0f, 0.0f, 1.0f
);
}
// static
Matrix3f Matrix3f::rotation( const Quat4f& rq )
{
Quat4f q = rq.normalized();
float xx = q.x() * q.x();
float yy = q.y() * q.y();
float zz = q.z() * q.z();
float xy = q.x() * q.y();
float zw = q.z() * q.w();
float xz = q.x() * q.z();
float yw = q.y() * q.w();
float yz = q.y() * q.z();
float xw = q.x() * q.w();
return Matrix3f
(
1.0f - 2.0f * ( yy + zz ), 2.0f * ( xy - zw ), 2.0f * ( xz + yw ),
2.0f * ( xy + zw ), 1.0f - 2.0f * ( xx + zz ), 2.0f * ( yz - xw ),
2.0f * ( xz - yw ), 2.0f * ( yz + xw ), 1.0f - 2.0f * ( xx + yy )
);
}
