Rotate an image and get back to its original position - opengles glkit

Question

I need to rotate an image in opengles GLkit and get it back to its original position in GLkit.

rotation += 5;
_modelViewMatrix = GLKMatrix4Rotate( _modelViewMatrix, GLKMathDegreesToRadians(5), 1, 0, 0);
_modelViewMatrix = GLKMatrix4Rotate( _modelViewMatrix, GLKMathDegreesToRadians(rotation), 1,0,0);

I need to move it in x axis for certain amount and getting back to its original position from where it started. How should i do it?

Answer 1

Here's some very crude code to roughly illustrate a potential solution:

 if(object.grabStart){
   vec3 startRot = object.transform.rotation;
   object.startRotReference = startRot;
}

rotation += 5;

object.RotateXYZ(rotation,0,0);

if(object.transform.rotation.x >= object.targetRotX)
  object.RotateToStartRot();