Hi there!
i am currently programming a rubiks cube for the playstation portable for my studies. so far it all works well except the rotation-control of the whole cube, so i'll explain it shortly:
the analog stick gives his X coordinate to the rotation function which adds this value with a small multiplicator to the total rotation angle around the global Y axis. the same with the analog stick's Y coordinate that lets the cube rotate around the global X axis.
to create the rotation matrix, the psp-api has a function sceGumRotateXYZ(float x, float y, float z) wich obviously uses euler angles.
so now my problem: the first rotation around the X-axis works well because the camera is fixed, but the second around the Y-axis rotates the cube around his local Y-axis, but i want it to rotate around the global Y-axis! for the first rotation it is similar if its around the global-world axis or the cube's local axis because they are the same, but for the second one the needed rotation-axis is transformed by the first one.
i don't know how to handle this situation. i just converted the Y-axis and the angle to euler angles with help of this article, but with the same fail-result. so i ask for your help.
greetings and best wishes
fabian