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.
   *
   */
  
  
  #include "rp_spot_light.h"
  
  #define _USE_MATH_DEFINES
  #include <math.h>
  
  
  /**
   * @brief Creates a new spot light
   * @details This creates a new spot light with default properties set. You should
   *   set at least a direction, fov, radius and position to make the light useful.
   */
  RPSpotLight::RPSpotLight() : RPLight(RPLight::LT_spot_light) {
      _radius = 10.0;
      _fov = 45.0;
      _direction.set(0, 0, -1);
  }
  
  /**
   * @brief Writes the light to a GPUCommand
   * @details This writes the spot light data to a GPUCommand.
   * @see RPLight::write_to_command
   *
   * @param cmd The target GPUCommand
   */
  void RPSpotLight::write_to_command(GPUCommand &cmd) {
      RPLight::write_to_command(cmd);
      cmd.push_float(_radius);
  
      // Encode FOV as cos(fov)
      cmd.push_float(cos(_fov / 360.0 * M_PI));
      cmd.push_vec3(_direction);
  }
  
  /**
   * @brief Inits the shadow sources of the light
   * @details This inits all required shadow sources for the spot light.
   * @see RPLight::init_shadow_sources
   */
  void RPSpotLight::init_shadow_sources() {
      nassertv(_shadow_sources.size() == 0);
      _shadow_sources.push_back(new ShadowSource());
  }
  
  /**
   * @brief Updates the shadow sources
   * @details This updates all shadow sources of the light.
   * @see RPLight::update_shadow_sources
   */
  void RPSpotLight::update_shadow_sources() {
      _shadow_sources[0]->set_resolution(get_shadow_map_resolution());
      _shadow_sources[0]->set_perspective_lens(_fov, _near_plane, _radius, _position, _direction);
  }
  
  