Magic Cube

    super(3,2);

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

  boolean faceIsVisible(int axis, int lr)

    {

    return (2*lr-1)*mCamera[axis] > 0.5f;

    }

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

// given precomputed mCamera and mPoint, respectively camera and touch point positions in ScreenSpace,

// cast this touch point onto the surface defined by the 'face' and write the cast coords to 'output'.

// Center of the 'face' = (0,0), third coord always +- cubeHalfSize.

  void castTouchPointOntoFace(int axis, int lr, float[] output)

    {

    float diff = mPoint[axis]-mCamera[axis];

    float ratio= diff!=0.0f ? ((lr-0.5f)-mCamera[axis])/diff : 0.0f;

    output[0] = (mPoint[0]-mCamera[0])*ratio + mCamera[0];

    output[1] = (mPoint[1]-mCamera[1])*ratio + mCamera[1];

    output[2] = (mPoint[2]-mCamera[2])*ratio + mCamera[2];

    }