/********************************************************************
**                Image Component Library (ICL)                    **
**                                                                 **
** Copyright (C) 2006-2013 CITEC, University of Bielefeld          **
**                         Neuroinformatics Group                  **
** Website: www.iclcv.org and                                      **
**          http://opensource.cit-ec.de/projects/icl               **
**                                                                 **
** File   : ICLCV/src/ICLCV/ContourDetector.h                      **
** Module : ICLCV                                                  **
** Authors: Sergius Gaulik, Christof Elbrechter                    **
**                                                                 **
**                                                                 **
** GNU LESSER GENERAL PUBLIC LICENSE                               **
** This file may be used under the terms of the GNU Lesser General **
** Public License version 3.0 as published by the                  **
**                                                                 **
** Free Software Foundation and appearing in the file LICENSE.LGPL **
** included in the packaging of this file.  Please review the      **
** following information to ensure the license requirements will   **
** be met: http://www.gnu.org/licenses/lgpl-3.0.txt                **
**                                                                 **
** The development of this software was supported by the           **
** Excellence Cluster EXC 277 Cognitive Interaction Technology.    **
** The Excellence Cluster EXC 277 is a grant of the Deutsche       **
** Forschungsgemeinschaft (DFG) in the context of the German       **
** Excellence Initiative.                                          **
**                                                                 **
********************************************************************/

#pragma once

#include <ICLUtils/CompatMacros.h>
#include <ICLUtils/Uncopyable.h>
#include <ICLCore/Img.h>

#include <vector>

namespace icl{
  namespace cv{
    
    struct ContourImpl{
      virtual bool hasHierarchy() const = 0;
      virtual int getID() const = 0;
      virtual bool isHole() const = 0;
      virtual const std::vector<int> &getChildren() const = 0;
      virtual const utils::Point *begin() const = 0;
      virtual const utils::Point *end() const = 0;
    };
    
    /// Utility class used by the ContourDetector
    class ICLCV_API Contour{ 
      ContourImpl *impl;

      public:
      Contour(ContourImpl *impl = 0):impl(impl){}
      
      inline bool isNull() const { 
        return !impl;
      }
      inline operator bool() const {
        return !!impl;
      }
      inline bool hasHierarchy() const{
        return impl->hasHierarchy();
      }
      inline int getID() const {
        return impl->getID();
      }
      bool isHole() const{
        return impl->isHole();
      }
      const std::vector<int> &getChildren() const{
        return impl->getChildren();
      }
      const utils::Point *begin() const{
        return impl->begin();
      }
      const utils::Point *end() const{
        return impl->end();
      }
      const int getSize() const{
        return (int)(end() - begin());
      }
      // draws the contour in the first channel of the given image
      void drawTo(core::ImgBase *img, const icl64f &value);
    };

    /// The ContourDetector extracts all contours of a given image.
    /** Internally, the implementation works on binary images only,
        but a compatiblity layer is provided that allows for working
        on arbitraryly-typed images by internally converting the input
        image before the compuation takes place. The algorithms alters
        the values of the input image for performance reasons. If a
        const image is passed to the ContourDetector::detect method,
        the image is copied/converted before

        \section HIER Contour Hierarchy
        
        The ContourDetector can be set up to also extract a countour
        hierarchy.
        
        \section ALG Algorithms
        
        Internally 2 different contour tracing algorithms are implemented. While
        the "Fast" method uses a 4-point neighbourhood, the Accurate method uses 
        a 8-point neighborhood an can also optionally be used to obtain a region
        hierarchy. The fast method uses its own memory allocator to improve runtime
        performance.

    **/
    class ICLCV_API ContourDetector : public utils::Uncopyable{
      
      /// internal data type
      struct Data;

      /// internal data pointer
      Data *m_data;
      
      public:
      
      /// contour tracing algorithm used
      enum Algorithm{
        Fast,                  //!< fast contour detection algorithm (using 4-point neighbourhood)
        Accurate,              //!< accurate contour detection algorithm (using 8-point neighborhood)
        AccurateWithHierarchy  //!< same as Accurate, but with Hierarchy estimation
      };

      // contructor
      /** @param thesh threshold for creating the binary image
          @param hierarchy shows if the relationship of the contours should be calculated
      */
      ContourDetector(const icl8u thresh=128, Algorithm a = Fast);
  
      // destructor
      virtual ~ContourDetector();

      // draws all contours to the first channel of the given image with the given value
      void drawAllContours(core::ImgBase *img, const icl64f &value);

      // calculates all contours (creates a deep copy/conversion to Img8u of the input image)
      const std::vector<Contour> &detect(const core::ImgBase *image);

      // calculates all controus (alters the values of the input image)
      const std::vector<Contour> &detect(core::Img8u &image);

      /// sets new binarization threshold
      void setThreshold(const icl8u &threshold);
      
      /// sets whether a contour hierarchy is created
      void setAlgorithm(Algorithm a);
    };
  
  } // namespace cv
}