mujoco

// Copyright 2025 DeepMind Technologies Limited
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef MUJOCO_SRC_RENDER_FILAMENT_SUPPORT_MODEL_LIGHTS_H_
#define MUJOCO_SRC_RENDER_FILAMENT_SUPPORT_MODEL_LIGHTS_H_

#include <vector>

#include <mujoco/mjrfilament.h>
#include <mujoco/mujoco.h>
#include "render/filament/mjrfilament_cpp.h"
#include "render/filament/support/model_objects.h"

namespace mujoco {

// Manages Light entities in an mjrfScene for an mjModel.
class ModelLights {
 public:
  ModelLights(mjrfScene* scene, ModelObjects* model_objects);
  ~ModelLights();

  // Updates the state of the lights in the scene.
  void Update(const mjData* data = nullptr);

  // Returns the light with the given index in the mjModel. Note that an extra
  // headlight is assigned of the index `nlight`.
  mjrfLight* GetLight(int index);

  ModelLights(const ModelLights&) = delete;
  ModelLights& operator=(const ModelLights&) = delete;

 private:
  void Prepare();

  // Applies changes of mjVisual quality.shadowsize to the lights' shadow
  // maps. A filament.shadows.map_size custom element remains in effect until
  // shadowsize is edited.
  void UpdateShadowMapSize();

  mjrfScene* scene_ = nullptr;
  ModelObjects* model_objects_ = nullptr;

  UniquePtr<mjrfLight> fallback_ibl_{nullptr, nullptr};
  UniquePtr<mjrfLight> fallback_directional_{nullptr, nullptr};
  UniquePtr<mjrfTexture> fallback_ibl_texture_{nullptr, nullptr};
  std::vector<UniquePtr<mjrfLight>> lights_;
  int shadowsize_ = 0;
  float fallback_head_light_intensity_ = 0.f;
  float fallback_scene_light_intensity_ = 80'000.f;
  float fallback_environment_light_intensity_ = 5'000.f;
};

}  // namespace mujoco

#endif  // MUJOCO_SRC_RENDER_FILAMENT_SUPPORT_MODEL_LIGHTS_H_