// ------------------------------------------------------------------
// R-C3D
// Copyright (c) 2017 Boston University
// Licensed under The MIT License [see LICENSE for details]
// Written by Huijuan Xu
// ------------------------------------------------------------------

#ifndef CAFFE_ROI_POOLING_LAYER_HPP_
#define CAFFE_ROI_POOLING_LAYER_HPP_

#include <vector>

#include "caffe/blob.hpp"
#include "caffe/common.hpp"
#include "caffe/layer.hpp"
#include "caffe/proto/caffe.pb.h"

#include "caffe/layers/loss_layer.hpp"

namespace caffe {

/* ROIPoolingLayer - Region of Interest Pooling Layer
 * */
template <typename Dtype>
class ROIPoolingLayer : public Layer<Dtype> {
 public:
  explicit ROIPoolingLayer(const LayerParameter& param)
      : Layer<Dtype>(param) {}
  virtual void LayerSetUp(const vector<Blob<Dtype>*>& bottom,
      const vector<Blob<Dtype>*>& top);
  virtual void Reshape(const vector<Blob<Dtype>*>& bottom,
      const vector<Blob<Dtype>*>& top);

  virtual inline const char* type() const { return "ROIPooling"; }

  virtual inline int MinBottomBlobs() const { return 2; }
  virtual inline int MaxBottomBlobs() const { return 2; }
  virtual inline int MinTopBlobs() const { return 1; }
  virtual inline int MaxTopBlobs() const { return 1; }

 protected:
  virtual void Forward_cpu(const vector<Blob<Dtype>*>& bottom,
      const vector<Blob<Dtype>*>& top);
  virtual void Forward_gpu(const vector<Blob<Dtype>*>& bottom,
      const vector<Blob<Dtype>*>& top);
  virtual void Backward_cpu(const vector<Blob<Dtype>*>& top,
      const vector<bool>& propagate_down, const vector<Blob<Dtype>*>& bottom);
  virtual void Backward_gpu(const vector<Blob<Dtype>*>& top,
      const vector<bool>& propagate_down, const vector<Blob<Dtype>*>& bottom);

  int channels_;
  int length_;
  int height_;
  int width_;
  int pooled_length_;
  int pooled_height_;
  int pooled_width_;
  Dtype temporal_scale_;
  Dtype spatial_scale_;
  Blob<int> max_idx_;
};

}  // namespace caffe

#endif  // CAFFE_ROI_POOLING_LAYER_HPP_

