text: // Tencent is pleased to support the open source community by making ncnn available.
  //
  // Copyright (C) 2017 THL A29 Limited, a Tencent company. All rights reserved.
  //
  // Licensed under the BSD 3-Clause License (the "License"); you may not use this file except
  // in compliance with the License. You may obtain a copy of the License at
  //
  // https://opensource.org/licenses/BSD-3-Clause
  //
  // 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 NCNN_LAYER_H
  #define NCNN_LAYER_H
  
  #include <stdio.h>
  #include <string>
  #include <vector>
  #include <math.h>
  #include "platform.h"
  #include "mat.h"
  #include "modelbin.h"
  #include "option.h"
  #include "paramdict.h"
  
  #if NCNN_VULKAN
  #include <vulkan/vulkan.h>
  #include "command.h"
  #include "pipeline.h"
  #endif // NCNN_VULKAN
  
  namespace ncnn {
  
  class Layer
  {
  public:
      // empty
      Layer();
      // virtual destructor
      virtual ~Layer();
  
      // load layer specific parameter from parsed dict
      // return 0 if success
      virtual int load_param(const ParamDict& pd);
  
      // load layer specific weight data from model binary
      // return 0 if success
      virtual int load_model(const ModelBin& mb);
  
      virtual void set_h(int h) {(void)(h);}
  
      // layer implementation specific setup
      // return 0 if success
      virtual int create_pipeline(const Option& opt = Option());
  
      // layer implementation specific clean
      // return 0 if success
      virtual int destroy_pipeline(const Option& opt = Option());
  
  public:
      // one input and one output blob
      bool one_blob_only;
  
      // support inplace inference
      bool support_inplace;
  
      // support vulkan compute
      bool support_vulkan;
  
      // accept input blob with packed storage
      bool support_packing;
  
  public:
      // implement inference
      // return 0 if success
      virtual int forward(const std::vector<Mat>& bottom_blobs, std::vector<Mat>& top_blobs, const Option& opt = Option()) const;
      virtual int forward(const Mat& bottom_blob, Mat& top_blob, const Option& opt = Option()) const;
  
      // implement inplace inference
      // return 0 if success
      virtual int forward_inplace(std::vector<Mat>& bottom_top_blobs, const Option& opt = Option()) const;
      virtual int forward_inplace(Mat& bottom_top_blob, const Option& opt = Option()) const;
  
  #if NCNN_VULKAN
  public:
      // upload weight blob from host to device
      virtual int upload_model(VkTransfer& cmd, const Option& opt = Option());
  
  public:
      // implement inference
      // return 0 if success
      virtual int forward(const std::vector<VkMat>& bottom_blobs, std::vector<VkMat>& top_blobs, VkCompute& cmd, const Option& opt = Option()) const;
      virtual int forward(const VkMat& bottom_blob, VkMat& top_blob, VkCompute& cmd, const Option& opt = Option()) const;
  
      // implement inplace inference
      // return 0 if success
      virtual int forward_inplace(std::vector<VkMat>& bottom_top_blobs, VkCompute& cmd, const Option& opt = Option()) const;
      virtual int forward_inplace(VkMat& bottom_top_blob, VkCompute& cmd, const Option& opt = Option()) const;
  
  public:
      // assigned immediately after creating this layer
      const VulkanDevice* vkdev;
  #endif // NCNN_VULKAN
  
  public:
      // layer type index
      int typeindex;
  #if NCNN_STRING
      // layer type name
      std::string type;
      // layer name
      std::string name;
  #endif // NCNN_STRING
      // blob index which this layer needs as input
      std::vector<int> bottoms;
      // blob index which this layer produces as output
      std::vector<int> tops;
  };
  
  // layer factory function
  typedef Layer* (*layer_creator_func)();
  
  struct layer_registry_entry
  {
  #if NCNN_STRING
      // layer type name
      const char* name;
  #endif // NCNN_STRING
      // layer factory entry
      layer_creator_func creator;
  };
  
  #if NCNN_STRING
  // get layer type from type name
  int layer_to_index(const char* type);
  // create layer from type name
  Layer* create_layer(const char* type);
  #endif // NCNN_STRING
  // create layer from layer type
  Layer* create_layer(int index);
  
  #define DEFINE_LAYER_CREATOR(name) \
      ::ncnn::Layer* name##_layer_creator() { return new name; }
  
  } // namespace ncnn
  
  #endif // NCNN_LAYER_H
  