SliceOrder

# from vtkmodules.vtkCommonMath import vtkMatrix4x4
# from vtkmodules.vtkCommonTransforms import vtkTransform


class SliceOrder:
    """
    These transformations permute image and other geometric data to maintain proper
     orientation regardless of the acquisition order. After applying these transforms with
    vtkTransformFilter, a view up of 0, -1, 0 will result in the body part
    facing the viewer.
    NOTE: some transformations have a -1 scale factor for one of the components.
          To ensure proper polygon orientation and normal direction, you must
          apply the vtkPolyDataNormals filter.

    Naming (the nomenclature is medical):
    si - superior to inferior (top to bottom)
    is - inferior to superior (bottom to top)
    ap - anterior to posterior (front to back)
    pa - posterior to anterior (back to front)
    lr - left to right
    rl - right to left
    """

    def __init__(self):
        self.si_mat = vtkMatrix4x4([[1, 0, 0, 0], [0, 0, 1, 0], [0, -1, 0, 0], [0, 0, 0, 1]])
        self.is_mat = vtkMatrix4x4([[1, 0, 0, 0], [0, 0, -1, 0], [0, -1, 0, 0], [0, 0, 0, 1]])
        self.lr_mat = vtkMatrix4x4([[0, 0, -1, 0], [0, -1, 0, 0], [1, 0, 0, 0], [0, 0, 0, 1]])
        self.rl_mat = vtkMatrix4x4([[0, 0, 1, 0], [0, -1, 0, 0], [1, 0, 0, 0], [0, 0, 0, 1]])

        self.transform = dict()

        si_trans = vtkTransform()
        si_trans.SetMatrix(self.si_mat)
        self.transform['si'] = si_trans

        is_trans = vtkTransform()
        is_trans.SetMatrix(self.is_mat)
        self.transform['is'] = is_trans

        ap_trans = vtkTransform()
        ap_trans.Scale(1, -1, 1)
        self.transform['ap'] = ap_trans

        pa_trans = vtkTransform()
        pa_trans.Scale(1, -1, -1)
        self.transform['pa'] = pa_trans

        lr_trans = vtkTransform()
        lr_trans.SetMatrix(self.lr_mat)
        self.transform['lr'] = lr_trans

        rl_trans = vtkTransform()
        rl_trans.SetMatrix(self.rl_mat)
        self.transform['rl'] = rl_trans

        """
        The previous transforms assume radiological views of the slices
         (viewed from the feet).
        Other modalities such as physical sectioning may view from the head.
        The following transforms modify the original with a 180° rotation
         about the y-axis.
        """

        self.hf_mat = vtkMatrix4x4([[-1, 0, 0, 0], [0, 1, 0, 0], [0, 0, -1, 0], [0, 0, 0, 1]])
        hf_trans = vtkTransform()
        hf_trans.SetMatrix(self.hf_mat)
        self.transform['hf'] = hf_trans

        hf_si_trans = vtkTransform()
        hf_si_trans.SetMatrix(self.hf_mat)
        hf_si_trans.Concatenate(self.si_mat)
        self.transform['hfsi'] = hf_si_trans

        hf_is_trans = vtkTransform()
        hf_is_trans.SetMatrix(self.hf_mat)
        hf_is_trans.Concatenate(self.is_mat)
        self.transform['hfis'] = hf_is_trans

        hf_ap_trans = vtkTransform()
        hf_ap_trans.SetMatrix(self.hf_mat)
        hf_ap_trans.Scale(1, -1, 1)
        self.transform['hfap'] = hf_ap_trans

        hf_pa_trans = vtkTransform()
        hf_pa_trans.SetMatrix(self.hf_mat)
        hf_pa_trans.Scale(1, -1, -1)
        self.transform['hfpa'] = hf_pa_trans

        hf_lr_trans = vtkTransform()
        hf_lr_trans.SetMatrix(self.hf_mat)
        hf_lr_trans.Concatenate(self.lr_mat)
        self.transform['hflr'] = hf_lr_trans

        hf_rl_trans = vtkTransform()
        hf_rl_trans.SetMatrix(self.hf_mat)
        hf_rl_trans.Concatenate(self.rl_mat)
        self.transform['hfrl'] = hf_rl_trans

        # Identity
        self.transform['I'] = vtkTransform()

        # Zero
        z_trans = vtkTransform()
        z_trans.Scale(0, 0, 0)
        self.transform['Z'] = z_trans

    def print_transform(self, order):
        """
        Print the homogenous matrix corresponding to the slice order.
        :param order: The slice order.
        :return:
        """
        print(order)
        m = self.transform[order].GetMatrix()
        for i in range(0, 4):
            row = list()
            for j in range(0, 4):
                row.append(f'{m.GetElement(i, j):>6.2g}')
            print(' '.join(row))

    def print_all_transforms(self):
        """
        Print all the homogenous matrices corresponding to the slice orders.
        :return:
        """
        print(self.transform.keys())
        for k in self.transform.keys():
            self.print_transform(k)

    def get(self, order):
        """
        Returns the vtkTransform corresponding to the slice order.

        :param order: The slice order.
        :return: The vtkTransform to use.
        """
        if order in self.transform.keys():
            return self.transform[order]
        else:
            s = 'No such transform "{:s}" exists.'.format(order)
            raise Exception(s)

    so = SliceOrder()
    # so.print_all_transforms()