reflections_node.h

/*
Copyright 2018 Google Inc. All Rights Reserved.
 
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 RESONANCE_AUDIO_GRAPH_REFLECTIONS_NODE_H_
#define RESONANCE_AUDIO_GRAPH_REFLECTIONS_NODE_H_
 
#include <vector>
 
#include "ambisonics/foa_rotator.h"
#include "api/resonance_audio_api.h"
#include "base/audio_buffer.h"
#include "base/misc_math.h"
#include "dsp/reflections_processor.h"
#include "graph/system_settings.h"
#include "node/processing_node.h"
 
namespace vraudio {
 
// Node that accepts a single mono buffer as input and outputs an ambisonically
// encoded sound field buffer of the mix of all the early room reflections.
class ReflectionsNode : public ProcessingNode {
 public:
  // Initializes |ReflectionsNode| class.
  //
  // @param system_settings Global system configuration.
  explicit ReflectionsNode(const SystemSettings& system_settings);
 
  // Updates the reflections. Depending on whether to use RT60s for reverb
  // according to the global system settings, the reflections are calculated
  // either by the current room properties or the proxy room properties.
  void Update();
 
 protected:
  // Implements ProcessingNode.
  const AudioBuffer* AudioProcess(const NodeInput& input) override;
 
 private:
  const SystemSettings& system_settings_;
 
  // First-order-ambisonics rotator to be used to rotate the reflections with
  // respect to the listener's orientation.
  FoaRotator foa_rotator_;
 
  // Processes and encodes reflections into an ambisonic buffer.
  ReflectionsProcessor reflections_processor_;
 
  // Most recently updated reflection properties.
  ReflectionProperties reflection_properties_;
 
  // Most recently updated listener position.
  WorldPosition listener_position_;
 
  size_t num_frames_processed_on_empty_input_;
 
  // Ambisonic output buffer.
  AudioBuffer output_buffer_;
 
  // Silence mono buffer to render reflection tails during the absence of input
  // buffers.
  AudioBuffer silence_mono_buffer_;
};
 
}  // namespace vraudio
 
#endif  // RESONANCE_AUDIO_GRAPH_REFLECTIONS_NODE_H_