StructuringElement.h

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//     ____   ______ __
//    / __ \ / ____// /
//   / /_/ // /    / /
//  / ____// /___ / /___   PixInsight Class Library
// /_/     \____//_____/   PCL 2.7.0
// ----------------------------------------------------------------------------
// pcl/StructuringElement.h - Released 2024-06-18T15:48:54Z
// ----------------------------------------------------------------------------
// This file is part of the PixInsight Class Library (PCL).
// PCL is a multiplatform C++ framework for development of PixInsight modules.
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// ----------------------------------------------------------------------------
 
#ifndef __PCL_StructuringElement_h
#define __PCL_StructuringElement_h
 
 
#include <pcl/Defs.h>
#include <pcl/Diagnostics.h>
 
#include <pcl/Atomic.h>
#include <pcl/AutoLock.h>
#include <pcl/Math.h>
#include <pcl/Rotate.h>     // Reverse()
#include <pcl/StringList.h> // BitmapStructure
#include <pcl/Utility.h>
#include <pcl/Vector.h>
 
#include <memory.h>
 
namespace pcl
{
 
// ----------------------------------------------------------------------------
 
class PCL_CLASS StructuringElement
{
public:
 
   using existence_mask_element = uint32;
 
   using existence_mask = GenericVector<existence_mask_element>;
 
   using existence_mask_set = GenericVector<existence_mask>;
 
   using existence_mask_count = GenericVector<int>;
 
   StructuringElement( int size = 3, int n = 1 )
      : m_size( Max( 3, size|1 ) )
      , m_mask( Max( 1, n ) )
      , m_count( 0, Max( 1, n ) )
   {
      PCL_PRECONDITION( size >= 3 )
      PCL_PRECONDITION( (size & 1) != 0 )
      PCL_PRECONDITION( n >= 1 )
      for ( int k = 0; k < NumberOfWays(); ++k )
         m_mask[k] = existence_mask( existence_mask_element( 0 ), NumberOfElements() );
   }
 
   StructuringElement( const StructuringElement& x )
      : m_size( x.m_size )
      , m_mask( x.NumberOfWays() )
      , m_count( 0, x.NumberOfWays() )
   {
      for ( int k = 0; k < NumberOfWays(); ++k )
         m_mask[k] = existence_mask( existence_mask_element( 0 ), NumberOfElements() );
   }
 
   virtual ~StructuringElement()
   {
   }
 
   virtual StructuringElement* Clone() const = 0;
 
   StructuringElement& operator =( const StructuringElement& x )
   {
      if ( &x != this )
      {
         volatile AutoLock lock( m_mutex );
         m_size = x.m_size;
         m_mask = existence_mask_set( x.NumberOfWays() );
         m_count = existence_mask_count( 0, x.NumberOfWays() );
         m_reflected = false;
         m_initialized = 0;
         for ( int k = 0; k < NumberOfWays(); ++k )
            m_mask[k] = existence_mask( existence_mask_element( 0 ), NumberOfElements() );
      }
      return *this;
   }
 
   int NumberOfWays() const
   {
      return int( m_mask.Length() );
   }
 
   int Size() const
   {
      return m_size;
   }
 
   int NumberOfElements() const
   {
      return m_size*m_size;
   }
 
   virtual bool IsBox( int k ) const
   {
      PCL_PRECONDITION( k >= 0 && k < NumberOfWays() )
      Initialize();
      return m_count[k] == NumberOfElements();
   }
 
   virtual bool ElementExists( int i, int j, int k ) const
   {
      PCL_PRECONDITION( i >= 0 && i < m_size )
      PCL_PRECONDITION( j >= 0 && j < m_size )
      PCL_PRECONDITION( k >= 0 && k < NumberOfWays() )
      return true;
   }
 
   template <typename T>
   void PeekElements( T* h1, int& nh1, const T* h, int k ) const
   {
      PCL_PRECONDITION( h1 != 0 )
      PCL_PRECONDITION( h != 0 )
      PCL_PRECONDITION( k >= 0 && k < NumberOfWays() )
      Initialize();
      nh1 = 0;
      for ( existence_mask::const_iterator m = m_mask[k].Begin(), m1 = m_mask[k].End(); m < m1; ++m, ++h )
         if ( *m )
         {
            *h1++ = *h;
            ++nh1;
         }
   }
 
   void Reflect()
   {
      Initialize();
      for ( existence_mask_set::iterator i = m_mask.Begin(); i != m_mask.End(); ++i )
         pcl::Reverse( i->Begin(), i->End() );
      m_reflected = !m_reflected;
   }
 
   bool IsReflected() const
   {
      return m_reflected;
   }
 
   void Initialize() const
   {
      if ( !m_initialized )
      {
         volatile AutoLock lock( m_mutex );
         if ( m_initialized.Load() == 0 )
         {
            int N = NumberOfWays();
            for ( int k = 0; k < N; ++k )
            {
               m_count[k] = 0; // redundant, but doesn't hurt
               existence_mask::iterator m = m_mask[k].Begin();
               for ( int i = 0; i < m_size; ++i )
                  for ( int j = 0; j < m_size; ++j, ++m )
                     if ( ElementExists( i, j, k ) )
                     {
                        *m = 1;
                        ++m_count[k];
                     }
                     else
                        *m = 0;
            }
 
            m_initialized.Store( 1 );
         }
      }
   }
 
private:
 
   /*
    * Structure size.
    */
   int                           m_size;
 
   /*
    * Element existence masks (one mask per way).
    * An element exists iff its corresponding mask element is nonzero.
    */
   mutable existence_mask_set    m_mask;
 
   /*
    * Number of existing elements for each way.
    */
   mutable existence_mask_count  m_count;
 
   /*
    * Flag true when the structure has been reflected.
    */
   bool                          m_reflected = false;
 
   /*
    * Flag true when existence masks have been calculated.
    */
   mutable AtomicInt             m_initialized;
 
   /*
    * Thread synchronization.
    */
   mutable Mutex                 m_mutex;
};
 
// ----------------------------------------------------------------------------
 
class PCL_CLASS BoxStructure : public StructuringElement
{
public:
 
   BoxStructure( int size )
      : StructuringElement( size, 1 )
   {
   }
 
   BoxStructure( const BoxStructure& ) = default;
 
   StructuringElement* Clone() const override
   {
      return new BoxStructure( *this );
   }
 
   bool IsBox( int k ) const override
   {
      PCL_PRECONDITION( k == 0 )
      return true;
   }
};
 
// ----------------------------------------------------------------------------
 
class PCL_CLASS CircularStructure : public StructuringElement
{
public:
 
   CircularStructure( int diameter )
      : StructuringElement( diameter, 1 )
   {
   }
 
   CircularStructure( const CircularStructure& ) = default;
 
   StructuringElement* Clone() const override
   {
      return new CircularStructure( *this );
   }
 
   bool IsBox( int k ) const override
   {
      PCL_PRECONDITION( k == 0 )
      return false;
   }
 
   bool ElementExists( int i, int j, int k ) const override
   {
      PCL_PRECONDITION( i >= 0 && i < Size() )
      PCL_PRECONDITION( j >= 0 && j < Size() )
      PCL_PRECONDITION( k == 0 )
      float n2 = 0.5F*Size();
      float di = i+0.5F - n2;
      float dj = j+0.5F - n2;
      return di*di + dj*dj <= n2*n2;
   }
};
 
// ----------------------------------------------------------------------------
 
class PCL_CLASS OrthogonalStructure : public StructuringElement
{
public:
 
   OrthogonalStructure( int size )
      : StructuringElement( size, 1 )
   {
   }
 
   OrthogonalStructure( const OrthogonalStructure& ) = default;
 
   StructuringElement* Clone() const override
   {
      return new OrthogonalStructure( *this );
   }
 
   bool IsBox( int k ) const override
   {
      PCL_PRECONDITION( k == 0 )
      return false;
   }
 
   bool ElementExists( int i, int j, int k ) const override
   {
      PCL_PRECONDITION( i >= 0 && i < Size() )
      PCL_PRECONDITION( j >= 0 && j < Size() )
      PCL_PRECONDITION( k == 0 )
      int n2 = Size() >> 1;
      return i == n2 || j == n2;
   }
};
 
// ----------------------------------------------------------------------------
 
class PCL_CLASS DiagonalStructure : public StructuringElement
{
public:
 
   DiagonalStructure( int size )
      : StructuringElement( size, 1 )
   {
   }
 
   DiagonalStructure( const DiagonalStructure& ) = default;
 
   StructuringElement* Clone() const override
   {
      return new DiagonalStructure( *this );
   }
 
   bool IsBox( int k ) const override
   {
      PCL_PRECONDITION( k == 0 )
      return false;
   }
 
   bool ElementExists( int i, int j, int k ) const override
   {
      PCL_PRECONDITION( i >= 0 && i < Size() )
      PCL_PRECONDITION( j >= 0 && j < Size() )
      PCL_PRECONDITION( k == 0 )
      return j == i || j == Size()-i-1;
   }
};
 
// ----------------------------------------------------------------------------
 
class PCL_CLASS StarStructure : public StructuringElement
{
public:
 
   StarStructure( int size )
      : StructuringElement( size, 1 )
   {
   }
 
   StarStructure( const StarStructure& ) = default;
 
   StructuringElement* Clone() const override
   {
      return new StarStructure( *this );
   }
 
   bool IsBox( int k ) const override
   {
      PCL_PRECONDITION( k == 0 )
      return false;
   }
 
   bool ElementExists( int i, int j, int k ) const override
   {
      PCL_PRECONDITION( i >= 0 && i < Size() )
      PCL_PRECONDITION( j >= 0 && j < Size() )
      PCL_PRECONDITION( k == 0 )
      int n2 = Size() >> 1;
      if ( i == n2 || j == n2 )
         return true;
      if ( j == i || j == Size()-i-1 )
      {
         float n2 = 0.5F*Size();
         float di = i+0.5F - n2;
         float dj = j+0.5F - n2;
         return di*di + dj*dj <= n2*n2;
      }
      return false;
   }
};
 
// ----------------------------------------------------------------------------
 
class PCL_CLASS ThreeWayStructure : public StructuringElement
{
public:
 
   ThreeWayStructure( int size )
      : StructuringElement( size, 3 )
   {
   }
 
   ThreeWayStructure( const ThreeWayStructure& ) = default;
 
   StructuringElement* Clone() const override
   {
      return new ThreeWayStructure( *this );
   }
 
   bool IsBox( int k ) const override
   {
      PCL_PRECONDITION( k >= 0 && k < 3 )
      return false;
   }
 
   bool ElementExists( int i, int j, int k ) const override
   {
      PCL_PRECONDITION( i >= 0 && i < Size() )
      PCL_PRECONDITION( j >= 0 && j < Size() )
      PCL_PRECONDITION( k >= 0 && k < 3 )
      int n2 = Size() >> 1;
      switch ( k )
      {
      default:
      case 0:  // central element
         return i == n2 && j == n2;
      case 1:  // horizontal and vertical elements
         return i == n2 || j == n2;
      case 2:  // diagonal elements
         return (j == i || j == Size()-i-1) && i != n2;
      }
   }
};
 
// ----------------------------------------------------------------------------
 
class PCL_CLASS BitmapStructure : public StructuringElement
{
public:
 
   using bitmap = IsoString;
 
   using bitmap_set = IsoStringList;
 
   BitmapStructure( const char** bitmaps, int size, int n = 1 )
      : StructuringElement( size, n )
   {
      PCL_PRECONDITION( bitmaps != nullptr )
      PCL_PRECONDITION( *bitmaps != '\0' )
      for ( int i = 0; i < NumberOfWays(); ++i )
         m_bitmaps.Add( bitmap( bitmaps[i] ) );
   }
 
   BitmapStructure( const BitmapStructure& ) = default;
 
   StructuringElement* Clone() const override
   {
      return new BitmapStructure( *this );
   }
 
   bool ElementExists( int i, int j, int k ) const override
   {
      PCL_PRECONDITION( i >= 0 && i < Size() )
      PCL_PRECONDITION( j >= 0 && j < Size() )
      PCL_PRECONDITION( k >= 0 && k < NumberOfWays() )
      return m_bitmaps[k][i + j*Size()] == 'x';
   }
 
protected:
 
   bitmap_set m_bitmaps;
};
 
// ----------------------------------------------------------------------------
 
} // pcl
 
#endif   // __PCL_StructuringElement_h
 
// ----------------------------------------------------------------------------
// EOF pcl/StructuringElement.h - Released 2024-06-18T15:48:54Z