如何求X Y Z旋转的四元数的向量

I am creating a very simple project on OpenGL and I'm stuck with rotations. I am trying to rotate an object indepentdently in all 3 axes: X, Y, and Z. I've had sleepless nights due to the "gimbal lock" problem after rotating about one axis. I've then learned that quaternions would solve my problem. I've researched about quaternions and implementd it, but I havent't been able to convert my rotations to quaternions. For example, if I want to rotate around Z axis 90 degrees, I just create the {0,0,1} vector for my quaternion and rotate it around that axis 90 degrees using the code here:I am creating a very simple project on OpenGL a