GLfloat* CTrackball::GetMatrix()
{
ATLTRACE("GetMatrix\n");
GLfloat m[16];
m_quat.CreateMatrix(m);
m_matRotation = m;
// first rotation, then translation (matrix multiplication applies these in reversed order,
// so this is translation * rotation)
// if we reverse order, i.e. res = rotation * translation, we will be rotating _translated_
// object around the origin
// ok, this needs little more explaining:
// when we think of global fixed coordinate system, the transformations are applied
// in reversed order (here: rotation, then translation). the effect is that our object
// gets rotated (around origin), and then translated (zoom/unzoom) into -Z
//
// when we think of object's local coordinate system, the translations seems to apply
// in order as they appear (here: translation, then rotation). so our object gets translated
// to the desired point in space, and then it's rotated around it's local origin.
// code is the same, just a matter of how we think of it.
CMatrix ret = m_matTranslation * m_matRotation;
ret.GetMatrix(m_matResult);
return (GLfloat *)&m_matResult;
}
