How do you, from within the single prim, align it pointing it's x-axis along the global x-axis and then read the angle of rotation around that axis?
I've tried the following, which seemed intuitive, but gives nonsense...
rotation rMyRot = llGetRot();
vector vFwd = llRot2Fwd(rMyRot);
rotation rBetween = llRotBetween(vFwd,<1.0,0.0,0.0>
;rotation rNewRot = rBetween * rMyRot;
llSetRot(rNewRot);
Shouldn't at this point the prim be lined up with the global x-axis?
And shouldn't I now be able to get the x-axis angle of rotation by...
vector eulerRot = llRot2Euler(rNewRot);
float angleX = eulerRot.x * RAD_TO_DEG;