text: // ----------------------------------------------------------------------------
  // -                        Open3D: www.open3d.org                            -
  // ----------------------------------------------------------------------------
  // The MIT License (MIT)
  //
  // Copyright (c) 2019 www.open3d.org
  //
  // 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.
  // ----------------------------------------------------------------------------
  
  #pragma once
  
  #include <memory>
  
  #include "open3d/visualization/rendering/MaterialModifier.h"
  
  /// @cond
  namespace filament {
  class MaterialInstance;
  class TextureSampler;
  }  // namespace filament
  /// @endcond
  
  namespace open3d {
  namespace visualization {
  namespace rendering {
  
  class FilamentMaterialModifier : public MaterialModifier {
  public:
      static filament::TextureSampler SamplerFromSamplerParameters(
              const TextureSamplerParameters& sampler_config);
  
      FilamentMaterialModifier(const std::shared_ptr<filament::MaterialInstance>&
                                       material_instance,
                               const MaterialInstanceHandle& id);
      FilamentMaterialModifier() = default;
  
      void Reset();
      void
      Init(const std::shared_ptr<filament::MaterialInstance>& material_instance,
           const MaterialInstanceHandle& id);
  
      MaterialModifier& SetParameter(const char* parameter, int value) override;
      MaterialModifier& SetParameter(const char* parameter, float value) override;
      MaterialModifier& SetParameter(const char* parameter,
                                     const Eigen::Vector3f& value) override;
      MaterialModifier& SetColor(const char* parameter,
                                 const Eigen::Vector3f& value,
                                 bool srgb) override;
      MaterialModifier& SetColor(const char* parameter,
                                 const Eigen::Vector4f& value,
                                 bool srgb) override;
  
      MaterialModifier& SetTexture(
              const char* parameter,
              const TextureHandle& texture,
              const TextureSamplerParameters& sampler) override;
  
      MaterialModifier& SetDoubleSided(bool double_sided) override;
  
      MaterialInstanceHandle Finish() override;
  
  private:
      MaterialInstanceHandle current_handle_;
      std::shared_ptr<filament::MaterialInstance> material_instance_;
  };
  
  }  // namespace rendering
  }  // namespace visualization
  }  // namespace open3d
  