TwistyPuzzleLib

import org.distorted.library.helpers.QuatHelper;

///////////////////////////////////////////////////////////////////////////////////////////////////

// cast the 3D axis we are currently rotating along (which is already casted to the surface of the

// currently touched face AND converted into a 4D vector - fourth 0) to a 2D in-screen-surface axis

  void getCastedRotAxis(float[] output, Static4D quat, float x, float y, float z, float w)

    {

    Static4D result = QuatHelper.rotateVectorByQuat(x,y,z,w, quat);

    float cx = result.get0();

    float cy = result.get1();

    float len= (float)Math.sqrt(cx*cx+cy*cy);

    if( len!=0 )

      {

      output[0] = cx/len;

      output[1] = cy/len;

      }

    else

      {

      output[0] = 1;

      output[1] = 0;

      }

    }