text: 
  //
  // This source file is part of appleseed.
  // Visit http://appleseedhq.net/ for additional information and resources.
  //
  // This software is released under the MIT license.
  //
  // Copyright (c) 2010-2013 Francois Beaune, Jupiter Jazz Limited
  // Copyright (c) 2014-2016 Francois Beaune, The appleseedhq Organization
  //
  // 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.
  //
  
  #ifndef APPLESEED_RENDERER_KERNEL_RENDERING_SCENEPICKER_H
  #define APPLESEED_RENDERER_KERNEL_RENDERING_SCENEPICKER_H
  
  // appleseed.renderer headers.
  #include "renderer/kernel/shading/shadingpoint.h"
  
  // appleseed.foundation headers.
  #include "foundation/math/transform.h"
  #include "foundation/math/vector.h"
  
  // appleseed.main headers.
  #include "main/dllsymbol.h"
  
  // Forward declarations.
  namespace renderer  { class Assembly; }
  namespace renderer  { class AssemblyInstance; }
  namespace renderer  { class BSDF; }
  namespace renderer  { class BSSRDF; }
  namespace renderer  { class Camera; }
  namespace renderer  { class EDF; }
  namespace renderer  { class Material; }
  namespace renderer  { class Object; }
  namespace renderer  { class ObjectInstance; }
  namespace renderer  { class Project; }
  namespace renderer  { class SurfaceShader; }
  namespace renderer  { class TraceContext; }
  
  namespace renderer
  {
  
  class APPLESEED_DLLSYMBOL ScenePicker
  {
    public:
      struct PickingResult
      {
          bool                            m_hit;
          foundation::Vector3d            m_point;                // world space
          double                          m_distance;             // world space
          ShadingPoint::PrimitiveType     m_primitive_type;
          foundation::Transformd          m_assembly_instance_transform;
  
          const Camera*                   m_camera;
          const AssemblyInstance*         m_assembly_instance;
          const Assembly*                 m_assembly;
          const ObjectInstance*           m_object_instance;
          const Object*                   m_object;
          const Material*                 m_material;
          const SurfaceShader*            m_surface_shader;
          const BSDF*                     m_bsdf;
          const BSSRDF*                   m_bssrdf;
          const EDF*                      m_edf;
      };
  
      explicit ScenePicker(const Project& project);
  
      ~ScenePicker();
  
      PickingResult pick(const foundation::Vector2d& ndc) const;
  
    private:
      struct Impl;
      Impl* impl;
  };
  
  }       // namespace renderer
  
  #endif  // !APPLESEED_RENDERER_KERNEL_RENDERING_SCENEPICKER_H
  