/*
 * Copyright 2011-2013 Blender Foundation
 *
 * 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 __LIGHT_H__
#define __LIGHT_H__

#include "kernel/kernel_types.h"

#include "graph/node.h"

#include "util/util_ies.h"
#include "util/util_thread.h"
#include "util/util_types.h"
#include "util/util_vector.h"

CCL_NAMESPACE_BEGIN

class Device;
class DeviceScene;
class Object;
class Progress;
class Scene;
class Shader;

class Light : public Node {
 public:
  NODE_DECLARE;

  Light();

  LightType type;
  float3 strength;
  float3 co;

  float3 dir;
  float size;
  float angle;

  float3 axisu;
  float sizeu;
  float3 axisv;
  float sizev;
  bool round;

  Transform tfm;

  int map_resolution;

  float spot_angle;
  float spot_smooth;

  bool cast_shadow;
  bool use_mis;
  bool use_diffuse;
  bool use_glossy;
  bool use_transmission;
  bool use_scatter;

  bool is_portal;
  bool is_enabled;

  Shader *shader;
  int samples;
  int max_bounces;
  uint random_id;

  void tag_update(Scene *scene);

  /* Check whether the light has contribution the scene. */
  bool has_contribution(Scene *scene);
};

class LightManager {
 public:
  bool use_light_visibility;
  bool need_update;

  /* Need to update background (including multiple importance map) */
  bool need_update_background;

  LightManager();
  ~LightManager();

  /* IES texture management */
  int add_ies(const string &ies);
  int add_ies_from_file(const string &filename);
  void remove_ies(int slot);

  void device_update(Device *device, DeviceScene *dscene, Scene *scene, Progress &progress);
  void device_free(Device *device, DeviceScene *dscene, const bool free_background = true);

  void tag_update(Scene *scene);

  /* Check whether there is a background light. */
  bool has_background_light(Scene *scene);

 protected:
  /* Optimization: disable light which is either unsupported or
   * which doesn't contribute to the scene or which is only used for MIS
   * and scene doesn't need MIS.
   */
  void disable_ineffective_light(Scene *scene);

  void device_update_points(Device *device, DeviceScene *dscene, Scene *scene);
  void device_update_distribution(Device *device,
                                  DeviceScene *dscene,
                                  Scene *scene,
                                  Progress &progress);
  void device_update_background(Device *device,
                                DeviceScene *dscene,
                                Scene *scene,
                                Progress &progress);
  void device_update_ies(DeviceScene *dscene);

  /* Check whether light manager can use the object as a light-emissive. */
  bool object_usable_as_light(Object *object);

  struct IESSlot {
    IESFile ies;
    uint hash;
    int users;
  };

  vector<IESSlot *> ies_slots;
  thread_mutex ies_mutex;
};

CCL_NAMESPACE_END

#endif /* __LIGHT_H__ */