You usually apply a transformation to your object before you draw them. There is three way to apply transormation:
[ul][li]use old deprecated openGL function like glTranslate, glRotate, glScale… etc…Use your math library to compute the transformation matrix and then use glLoadMatrix Apply the transformation matrix as an uniform in your shader[/ul][/li]In the last two points you already know the modelview matrix.
In case 1 openGL compute the matrix for you (taking care of multiple transformation, hierarchy, and camera transformation). To get the current modelview matrix you have to call
obviously I don’t have/want to repeat again that using glGet slow down the whole program. So if performance is critical use point 2 or 3