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 __future__ import division
  
  from panda3d.core import CS_yup_right, CS_zup_right, invert, Vec3, Mat4, Vec4
  from panda3d.core import SamplerState
  from direct.stdpy.file import open
  
  from rpcore.globals import Globals
  from rpcore.rpobject import RPObject
  from rpcore.loader import RPLoader
  
  from rpcore.util.shader_input_blocks import GroupedInputBlock
  
  
  class CommonResources(RPObject):
  
      """ This class manages the loading and binding of commonly used resources,
      such as textures, models, but also shader inputs """
  
      def __init__(self, pipeline):
          RPObject.__init__(self)
          self._pipeline = pipeline
          self._showbase = Globals.base
          self._ptas = {}
          self._load_fonts()
          self._load_textures()
          self._setup_inputs()
  
      def _load_fonts(self):
          """ Loads the default font used for rendering and assigns it to
          Globals.font for further usage """
          font = RPLoader.load_font("/$$rp/data/font/Roboto-Medium.ttf")
          font.set_pixels_per_unit(35)
          font.set_poly_margin(0.0)
          font.set_texture_margin(1)
          font.set_bg(Vec4(1, 1, 1, 0))
          font.set_fg(Vec4(1, 1, 1, 1))
          Globals.font = font
  
      def _setup_inputs(self):
          """ Creates commonly used shader inputs such as the current mvp and
          registers them to the stage manager so they can be used for rendering """
  
          self._input_ubo = GroupedInputBlock("MainSceneData")
          inputs = (
              ("camera_pos", "vec3"),
              ("view_proj_mat_no_jitter", "mat4"),
              ("last_view_proj_mat_no_jitter", "mat4"),
              ("last_inv_view_proj_mat_no_jitter", "mat4"),
              ("view_mat_z_up", "mat4"),
              ("proj_mat", "mat4"),
              ("inv_proj_mat", "mat4"),
              ("view_mat_billboard", "mat4"),
              ("frame_delta", "float"),
              ("smooth_frame_delta", "float"),
              ("frame_time", "float"),
              ("current_film_offset", "vec2"),
              ("frame_index", "int"),
              ("screen_size", "ivec2"),
              ("native_screen_size", "ivec2"),
              ("lc_tile_count", "ivec2"),
              ("ws_frustum_directions", "mat4"),
              ("vs_frustum_directions", "mat4"),
          )
          for name, ipt_type in inputs:
              self._input_ubo.register_pta(name, ipt_type)
  
          self._pipeline.stage_mgr.input_blocks.append(self._input_ubo)
  
          # Main camera and main render have to be regular inputs, since they are
          # used in the shaders by that name.
          self._pipeline.stage_mgr.inputs["mainCam"] = self._showbase.cam
          self._pipeline.stage_mgr.inputs["mainRender"] = self._showbase.render
  
          # Set the correct frame rate interval
          Globals.clock.set_average_frame_rate_interval(3.0)
  
          # Set initial value for view_proj_mat_no_jitter
          view_mat = Globals.render.get_transform(self._showbase.cam).get_mat()
          proj_mat = Mat4(self._showbase.camLens.get_projection_mat())
          proj_mat.set_cell(1, 0, 0.0)
          proj_mat.set_cell(1, 1, 0.0)
          self._input_ubo.update_input("view_proj_mat_no_jitter", view_mat * proj_mat)
  
      def write_config(self):
          """ Generates the shader configuration for the common inputs """
          content = self._input_ubo.generate_shader_code()
          try:
              # Try to write the temporary file
              with open("/$$rptemp/$$main_scene_data.inc.glsl", "w") as handle:
                  handle.write(content)
          except IOError as msg:
              self.error("Failed to write common resources shader configuration!", msg)
  
      def _load_textures(self):
          """ Loads commonly used textures and makes them available via the
          stage manager """
          self._load_environment_cubemap()
          self._load_prefilter_brdf()
          self._load_skydome()
  
      def _load_environment_cubemap(self):
          """ Loads the default cubemap used for the environment, which is used
          when no other environment data is available """
          envmap = RPLoader.load_cube_map(
              "/$$rp/data/default_cubemap/cubemap.txo", read_mipmaps=True)
          envmap.set_minfilter(SamplerState.FT_linear_mipmap_linear)
          # envmap.set_format(Image.F_rgba16)
          envmap.set_magfilter(SamplerState.FT_linear)
          envmap.set_wrap_u(SamplerState.WM_repeat)
          envmap.set_wrap_v(SamplerState.WM_repeat)
          envmap.set_wrap_w(SamplerState.WM_repeat)
          self._pipeline.stage_mgr.inputs["DefaultEnvmap"] = envmap
  
      def _load_prefilter_brdf(self):
          """ Loads the prefiltered brdf """
          luts = [
              {"src": "slices/env_brdf_#.png", "input": "PrefilteredBRDF"},
              {"src": "slices_metal/env_brdf.png", "input": "PrefilteredMetalBRDF"},
              {"src": "slices_coat/env_brdf.png", "input": "PrefilteredCoatBRDF"},
          ]
  
          for config in luts:
              loader_method = RPLoader.load_texture
              if "#" in config["src"]:
                  loader_method = RPLoader.load_3d_texture
  
              brdf_tex = loader_method("/$$rp/data/environment_brdf/{}".format(config["src"]))
              brdf_tex.set_minfilter(SamplerState.FT_linear)
              brdf_tex.set_magfilter(SamplerState.FT_linear)
              brdf_tex.set_wrap_u(SamplerState.WM_clamp)
              brdf_tex.set_wrap_v(SamplerState.WM_clamp)
              brdf_tex.set_wrap_w(SamplerState.WM_clamp)
              brdf_tex.set_anisotropic_degree(0)
              self._pipeline.stage_mgr.inputs[config["input"]] = brdf_tex
  
      def _load_skydome(self):
          """ Loads the skydome """
          skydome = RPLoader.load_texture("/$$rp/data/builtin_models/skybox/skybox.txo")
          skydome.set_wrap_u(SamplerState.WM_clamp)
          skydome.set_wrap_v(SamplerState.WM_clamp)
          self._pipeline.stage_mgr.inputs["DefaultSkydome"] = skydome
  
      def load_default_skybox(self):
          skybox = RPLoader.load_model("/$$rp/data/builtin_models/skybox/skybox.bam")
          return skybox
  
      def update(self):
          """ Updates the commonly used resources, mostly the shader inputs """
          update = self._input_ubo.update_input
  
          # Get the current transform matrix of the camera
          view_mat = Globals.render.get_transform(self._showbase.cam).get_mat()
  
          # Compute the view matrix, but with a z-up coordinate system
          zup_conversion = Mat4.convert_mat(CS_zup_right, CS_yup_right)
          update("view_mat_z_up", view_mat * zup_conversion)
  
          # Compute the view matrix without the camera rotation
          view_mat_billboard = Mat4(view_mat)
          view_mat_billboard.set_row(0, Vec3(1, 0, 0))
          view_mat_billboard.set_row(1, Vec3(0, 1, 0))
          view_mat_billboard.set_row(2, Vec3(0, 0, 1))
          update("view_mat_billboard", view_mat_billboard)
  
          update("camera_pos", self._showbase.camera.get_pos(Globals.render))
  
          # Compute last view projection mat
          curr_vp = self._input_ubo.get_input("view_proj_mat_no_jitter")
          update("last_view_proj_mat_no_jitter", curr_vp)
          curr_vp = Mat4(curr_vp)
          curr_vp.invert_in_place()
          curr_inv_vp = curr_vp
          update("last_inv_view_proj_mat_no_jitter", curr_inv_vp)
  
          proj_mat = Mat4(self._showbase.camLens.get_projection_mat())
  
          # Set the projection matrix as an input, but convert it to the correct
          # coordinate system before.
          proj_mat_zup = Mat4.convert_mat(CS_yup_right, CS_zup_right) * proj_mat
          update("proj_mat", proj_mat_zup)
  
          # Set the inverse projection matrix
          update("inv_proj_mat", invert(proj_mat_zup))
  
          # Remove jitter and set the new view projection mat
          proj_mat.set_cell(1, 0, 0.0)
          proj_mat.set_cell(1, 1, 0.0)
          update("view_proj_mat_no_jitter", view_mat * proj_mat)
  
          # Store the frame delta
          update("frame_delta", Globals.clock.get_dt())
          update("smooth_frame_delta", 1.0 / max(1e-5, Globals.clock.get_average_frame_rate()))
          update("frame_time", Globals.clock.get_frame_time())
  
          # Store the current film offset, we use this to compute the pixel-perfect
          # velocity, which is otherwise not possible. Usually this is always 0
          # except when SMAA and reprojection is enabled
          update("current_film_offset", self._showbase.camLens.get_film_offset())
          update("frame_index", Globals.clock.get_frame_count())
  
          # Compute frustum corners in the order BL, BR, TL, TR
          ws_frustum_directions = Mat4()
          vs_frustum_directions = Mat4()
          inv_proj_mat = Globals.base.camLens.get_projection_mat_inv()
          view_mat_inv = Mat4(view_mat)
          view_mat_inv.invert_in_place()
  
          for i, point in enumerate(((-1, -1), (1, -1), (-1, 1), (1, 1))):
              result = inv_proj_mat.xform(Vec4(point[0], point[1], 1.0, 1.0))
              vs_dir = (zup_conversion.xform(result)).xyz.normalized()
              vs_frustum_directions.set_row(i, Vec4(vs_dir, 1))
              ws_dir = view_mat_inv.xform(Vec4(result.xyz, 0))
              ws_frustum_directions.set_row(i, ws_dir)
  
          update("vs_frustum_directions", vs_frustum_directions)
          update("ws_frustum_directions", ws_frustum_directions)
  
          update("screen_size", Globals.resolution)
          update("native_screen_size", Globals.native_resolution)
          update("lc_tile_count", self._pipeline.light_mgr.num_tiles)
  