MultiLayerNeuralTopology.h

//-------------------------------------------------------------------------------------------------------
// Copyright (C) Taylor Woll and panann contributors. All rights reserved.
// Licensed under the MIT license. See LICENSE.txt file in the project root for
// full license information.
//-------------------------------------------------------------------------------------------------------
 
#ifndef MULTILAYERTOPOLOGY_H__
#define MULTILAYERTOPOLOGY_H__
 
#include <vector>
 
#include "NeuronContainer.h"
 
namespace panann {
 
class MultiLayerNeuralTopology : public NeuronContainer {
 protected:
  struct Layer {
    size_t neuron_start_index;
 
    size_t neuron_count;
  };
 
  struct InputConnection {
    size_t from_neuron_index;
    size_t to_neuron_index;
  };
 
  struct OutputConnection {
    size_t input_connection_index;
  };
 
 public:
  MultiLayerNeuralTopology() = default;
  MultiLayerNeuralTopology(const MultiLayerNeuralTopology&) = delete;
  MultiLayerNeuralTopology& operator=(const MultiLayerNeuralTopology&) = delete;
  ~MultiLayerNeuralTopology() override = default;
 
  void AddHiddenLayer(size_t neuron_count);
 
  void EnableShortcutConnections();
  void DisableShortcutConnections();
 
  void ConstructTopology();
 
  bool IsTopologyConstructed() const;
 
  size_t GetHiddenLayerCount() const;
 
  const Layer& GetHiddenLayer(size_t layer_index) const;
 
  size_t GetInputConnectionCount() const;
 
  size_t GetOutputConnectionCount() const;
 
  const InputConnection& GetInputConnection(size_t index) const;
 
  const OutputConnection& GetOutputConnection(size_t index) const;
 
 protected:
  Layer& GetHiddenLayer(size_t layer_index);
 
  InputConnection& GetInputConnection(size_t index);
 
  OutputConnection& GetOutputConnection(size_t index);
 
  size_t AddInputConnections(size_t count);
 
  size_t AddOutputConnections(size_t count);
 
  virtual void FixNeuronConnectionIndices();
 
  void AllocateConnections();
 
  bool AreConnectionsAllocated() const;
 
  virtual void ConnectFully();
  void ConnectLayerToNeuron(size_t from_neuron_index, size_t from_neuron_count,
                            size_t to_neuron_index);
  void ConnectLayers(size_t from_neuron_index, size_t from_neuron_count,
                     size_t to_neuron_index, size_t to_neuron_count);
  void ConnectBiasNeuron(size_t bias_neuron_index, size_t to_neuron_index,
                         size_t to_neuron_count);
  void ConnectNeurons(size_t from_neuron_index, size_t to_neuron_index);
 
 private:
  std::vector<Layer> hidden_layers_;
  std::vector<InputConnection> input_connections_;
  size_t input_connection_count_ = 0;
  std::vector<OutputConnection> output_connections_;
  size_t output_connection_count_ = 0;
 
  bool enable_shortcut_connections_ = false;
  bool is_constructed_ = false;
  bool is_allocated_ = false;
};
 
}  // namespace panann
 
#endif  // MULTILAYERTOPOLOGY_H__