text: """
  
  RenderPipeline
  
  Copyright (c) 2014-2016 tobspr <tobias.springer1@gmail.com>
  
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
  
  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.
  
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  THE SOFTWARE.
  
  """
  
  from panda3d.core import PTALVecBase2f, PTALMatrix4f, Vec2, OrthographicLens
  from panda3d.core import Camera, NodePath, Mat4
  
  from rpcore.util.generic import snap_shadow_map
  
  class PSSMCameraRig(object):
  
      """ PSSM is not really supported in python yet (too slow), so this is a stub,
      supporting only one cascade """
  
      def __init__(self, num_splits):
          self._split_count = num_splits
          self._mvps = PTALMatrix4f.empty_array(num_splits)
          self._nearfar = PTALVecBase2f.empty_array(num_splits)
          for i in range(num_splits):
              self._nearfar[i] = Vec2(20, 1000)
              mat = Mat4()
              mat.fill(0)
              self._mvps[i] = mat
          self._lens = OrthographicLens()
          self._lens.set_near_far(20, 1000)
          self._lens.set_film_size(100, 100)
          self._camera = Camera("PSSMDummy", self._lens)
          self._cam_node = NodePath(self._camera)
          self._parent = None
          self._resolution = 1024
          self._snap_grid = True
          self._sun_distance = 500.0
  
      def set_resolution(self, resolution):
          self._resolution = resolution
  
      def update(self, cam_node, light_vector):
          cam_pos = cam_node.get_pos()
          self._cam_node.set_pos(cam_pos + light_vector * self._sun_distance)
          self._cam_node.look_at(cam_pos)
  
          if self._snap_grid:
              snap_shadow_map(self.compute_mvp(), self._cam_node, self._resolution)
  
          self._mvps[0] = self.compute_mvp()
  
      def compute_mvp(self):
          transform = self._parent.get_transform(self._cam_node).get_mat()
          return transform * self._lens.get_projection_mat()
  
      def get_camera(self, index): # pylint: disable=W0613
          return self._cam_node
  
      def set_sun_distance(self, dist):
          self._sun_distance = dist
          self._lens.set_near_far(10, 2 * dist)
  
      def reparent_to(self, parent):
          self._cam_node.reparent_to(parent)
          self._parent = parent
  
      def get_mvp_array(self):
          return self._mvps
  
      def get_nearfar_array(self):
          return self._nearfar
  
      def set_use_stable_csm(self, use_stable):
          self._snap_grid = use_stable
  
      def _stub(self, *args, **kwargs): # pylint: disable=W0613
          return None
  
      set_pssm_distance = _stub
      set_logarithmic_factor = _stub
      set_border_bias = _stub
      set_use_fixed_film_size = _stub
      reset_film_size_cache = _stub
  