X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?a=blobdiff_plain;f=lib%2Ffpa%2FBase%2FMinimumSpanningTree.hxx;h=e8ed6a2c286e94b5701e022531a9e418a105cec1;hb=a993dd7dc7f3154d00eed3d3a4796fb9e3ff582d;hp=d932247c7bc2dcbc739e5902848da20879509bb5;hpb=b4ed6ddfa7e90e892f07cad9a760961bd4e84e6b;p=FrontAlgorithms.git

diff --git a/lib/fpa/Base/MinimumSpanningTree.hxx b/lib/fpa/Base/MinimumSpanningTree.hxx
index d932247..e8ed6a2 100644
--- a/lib/fpa/Base/MinimumSpanningTree.hxx
+++ b/lib/fpa/Base/MinimumSpanningTree.hxx
@@ -1,28 +1,38 @@
-#ifndef __FPA__BASE__MINIMUMSPANNINGTREE__HXX__
-#define __FPA__BASE__MINIMUMSPANNINGTREE__HXX__
+#ifndef __fpa__Base__MinimumSpanningTree__hxx__
+#define __fpa__Base__MinimumSpanningTree__hxx__
 
 #include <limits>
 
 // -------------------------------------------------------------------------
-template< class V, class C, class B >
-const unsigned long fpa::Base::MinimumSpanningTree< V, C, B >::INF_VALUE =
-  std::numeric_limits< unsigned long >::max( ) >> 1;
+template< class _TVertex, class _TPath, class _TSuperclass >
+const typename
+fpa::Base::MinimumSpanningTree< _TVertex, _TPath, _TSuperclass >::
+TCollisions&
+fpa::Base::MinimumSpanningTree< _TVertex, _TPath, _TSuperclass >::
+GetCollisions( ) const
+{
+  return( this->m_Collisions );
+}
 
 // -------------------------------------------------------------------------
-template< class V, class C, class B >
-void fpa::Base::MinimumSpanningTree< V, C, B >::
+template< class _TVertex, class _TPath, class _TSuperclass >
+void fpa::Base::MinimumSpanningTree< _TVertex, _TPath, _TSuperclass >::
 SetCollisions( const TCollisions& collisions )
 {
+  static const unsigned long _inf =
+    std::numeric_limits< unsigned long >::max( );
+  if( this->m_Collisions == collisions )
+    return;
+
   this->m_Collisions = collisions;
 
-  // Prepare fronts graph using Floyd-Warshall
-  unsigned long nSeeds = this->m_Collisions.size( );
-  _TMatrix dist( nSeeds, _TRow( nSeeds, Self::INF_VALUE ) );
+  // Prepare a front graph
+  unsigned long N = this->m_Collisions.size( );
+  _TMatrix dist( N, _TRow( N, _inf ) );
   this->m_FrontPaths = dist;
-
-  for( unsigned long i = 0; i < nSeeds; ++i )
+  for( unsigned long i = 0; i < N; ++i )
   {
-    for( unsigned long j = 0; j < nSeeds; ++j )
+    for( unsigned long j = 0; j < N; ++j )
     {
       if( this->m_Collisions[ i ][ j ].second )
       {
@@ -38,15 +48,25 @@ SetCollisions( const TCollisions& collisions )
     this->m_FrontPaths[ i ][ i ] = i;
 
   } // rof
-  for( unsigned long k = 0; k < nSeeds; ++k )
+
+  // Use Floyd-Warshall to compute all possible paths between fronts
+  for( unsigned long k = 0; k < N; ++k )
   {
-    for( unsigned long i = 0; i < nSeeds; ++i )
+    for( unsigned long i = 0; i < N; ++i )
     {
-      for( unsigned long j = 0; j < nSeeds; ++j )
+      for( unsigned long j = 0; j < N; ++j )
       {
-        if( ( dist[ i ][ k ] + dist[ k ][ j ] ) < dist[ i ][ j ] )
+        // WARNING: you don't want a numeric overflow!!!
+        unsigned long dik = dist[ i ][ k ];
+        unsigned long dkj = dist[ k ][ j ];
+        unsigned long sum = _inf;
+        if( dik < _inf && dkj < _inf )
+          sum = dik + dkj;
+
+        // Ok, continue Floyd-Warshall
+        if( sum < dist[ i ][ j ] )
         {
-          dist[ i ][ j ] = dist[ i ][ k ] + dist[ k ][ j ];
+          dist[ i ][ j ] = sum;
           this->m_FrontPaths[ i ][ j ] = this->m_FrontPaths[ i ][ k ];
 
         } // fi
@@ -60,89 +80,144 @@ SetCollisions( const TCollisions& collisions )
 }
 
 // -------------------------------------------------------------------------
-template< class V, class C, class B >
-void fpa::Base::MinimumSpanningTree< V, C, B >::
-GetPath( std::vector< V >& path, const V& a, const V& b ) const
+template< class _TVertex, class _TPath, class _TSuperclass >
+void fpa::Base::MinimumSpanningTree< _TVertex, _TPath, _TSuperclass >::
+ClearSeeds( )
 {
-  typename TDecorated::const_iterator aIt = this->Get( ).find( a );
-  typename TDecorated::const_iterator bIt = this->Get( ).find( b );
+  this->m_Seeds.clear( );
+  this->Modified( );
+}
 
-  if( aIt == this->Get( ).end( ) || bIt == this->Get( ).end( ) )
-    return;
-  
-  short fa = aIt->second.second;
-  short fb = bIt->second.second;
+// -------------------------------------------------------------------------
+template< class _TVertex, class _TPath, class _TSuperclass >
+void fpa::Base::MinimumSpanningTree< _TVertex, _TPath, _TSuperclass >::
+AddSeed( const _TVertex& seed )
+{
+  this->m_Seeds.push_back( seed );
+  this->Modified( );
+}
 
-  if( fa == fb )
+// -------------------------------------------------------------------------
+template< class _TVertex, class _TPath, class _TSuperclass >
+void fpa::Base::MinimumSpanningTree< _TVertex, _TPath, _TSuperclass >::
+GetPath( typename _TPath::Pointer& path, const _TVertex& a ) const
+{
+  std::vector< _TVertex > vertices;
+  _TVertex it = a;
+  _TVertex p = this->GetParent( it );
+  while( it != p )
   {
-    std::vector< V > ap, bp;
-    this->_Path( ap, a );
-    this->_Path( bp, b );
-
-    // Ignore common part
-    typename std::vector< V >::const_reverse_iterator raIt, rbIt;
-    raIt = ap.rbegin( );
-    rbIt = bp.rbegin( );
-    while( *raIt == *rbIt && raIt != ap.rend( ) && rbIt != bp.rend( ) )
-    {
-      ++raIt;
-      ++rbIt;
-
-    } // elihw
-    if( raIt != ap.rbegin( ) ) --raIt;
-    if( rbIt != bp.rbegin( ) ) --rbIt;
-
-    // Add part from a
-    typename std::vector< V >::const_iterator iaIt = ap.begin( );
-    for( ; iaIt != ap.end( ) && *iaIt != *raIt; ++iaIt )
-      path.push_back( *iaIt );
-
-    // Add part from b
-    for( ; rbIt != bp.rend( ); ++rbIt )
-      path.push_back( *rbIt );
-  }
-  else
+    vertices.push_back( it );
+    it = p;
+    p = this->GetParent( it );
+
+  } // elihw
+  vertices.push_back( it );
+
+  if( path.IsNull( ) )
+    path = _TPath::New( );
+  for( auto v = vertices.begin( ); v != vertices.end( ); ++v )
+    path->AddVertex( *v );
+}
+
+// -------------------------------------------------------------------------
+template< class _TVertex, class _TPath, class _TSuperclass >
+void fpa::Base::MinimumSpanningTree< _TVertex, _TPath, _TSuperclass >::
+GetPath(
+  typename _TPath::Pointer& path, const _TVertex& a, const _TVertex& b
+  ) const
+{
+  static const unsigned long _inf =
+    std::numeric_limits< unsigned long >::max( );
+
+  if( path.IsNull( ) )
+    path = _TPath::New( );
+  typename _TPath::Pointer pa, pb;
+  this->GetPath( pa, a );
+  this->GetPath( pb, b );
+  if( pa->GetSize( ) > 0 && pb->GetSize( ) > 0 )
   {
-    // Use this->m_FrontPaths from Floyd-Warshall
-    if( this->m_FrontPaths[ fa ][ fb ] != Self::INF_VALUE )
+    // Find front identifiers
+    unsigned long ia = _inf, ib = _inf;
+    unsigned long N = this->m_Seeds.size( );
+    for( unsigned long i = 0; i < N; ++i )
+    {
+      if( this->m_Seeds[ i ] == pa->GetVertex( pa->GetSize( ) - 1 ) )
+        ia = i;
+      if( this->m_Seeds[ i ] == pb->GetVertex( pb->GetSize( ) - 1 ) )
+        ib = i;
+
+    } // rof
+
+    // Check if there is a front-jump between given seeds
+    if( ia != ib )
     {
       // Compute front path
       std::vector< long > fpath;
-      fpath.push_back( fa );
-      while( fa != fb )
+      fpath.push_back( ia );
+      while( ia != ib )
       {
-        fa = this->m_FrontPaths[ fa ][ fb ];
-        fpath.push_back( fa );
+        ia = this->m_FrontPaths[ ia ][ ib ];
+        fpath.push_back( ia );
 
       } // elihw
 
       // Continue only if both fronts are connected
       unsigned int N = fpath.size( );
-      if( 0 < N )
+      if( N > 0 )
       {
         // First path: from start vertex to first collision
         this->GetPath(
-          path, a, this->m_Collisions[ fpath[ 0 ] ][ fpath[ 1 ] ].first
+          path, a,
+          this->m_Collisions[ fpath[ 0 ] ][ fpath[ 1 ] ].first
           );
 
         // Intermediary paths
         for( unsigned int i = 1; i < N - 1; ++i )
         {
+          typename _TPath::Pointer ipath;
           this->GetPath(
-            path,
+            ipath,
             this->m_Collisions[ fpath[ i ] ][ fpath[ i - 1 ] ].first,
             this->m_Collisions[ fpath[ i ] ][ fpath[ i + 1 ] ].first
             );
+          for( long id = 0; id < ipath->GetSize( ); ++id )
+            path->AddVertex( ipath->GetVertex( id ) );
 
         } // rof
 
         // Final path: from last collision to end point
+        typename _TPath::Pointer lpath;
         this->GetPath(
-          path,
+          lpath,
           this->m_Collisions[ fpath[ N - 1 ] ][ fpath[ N - 2 ] ].first, b
           );
+        for( long id = 0; id < lpath->GetSize( ); ++id )
+          path->AddVertex( lpath->GetVertex( id ) );
 
       } // fi
+    }
+    else
+    {
+      // Ignore common part: find common ancestor
+      long aIt = pa->GetSize( ) - 1;
+      long bIt = pb->GetSize( ) - 1;
+      bool cont = true;
+      while( aIt >= 0 && bIt >= 0 && cont )
+      {
+        cont = ( pa->GetVertex( aIt ) == pb->GetVertex( bIt ) );
+        aIt--;
+        bIt--;
+
+      } // elihw
+      aIt++;
+      bIt++;
+
+      // Glue both parts
+      for( long cIt = 0; cIt <= aIt; ++cIt )
+        path->AddVertex( pa->GetVertex( cIt ) );
+      for( ; bIt >= 0; --bIt )
+        path->AddVertex( pb->GetVertex( bIt ) );
 
     } // fi
 
@@ -150,41 +225,20 @@ GetPath( std::vector< V >& path, const V& a, const V& b ) const
 }
 
 // -------------------------------------------------------------------------
-template< class V, class C, class B >
-fpa::Base::MinimumSpanningTree< V, C, B >::
+template< class _TVertex, class _TPath, class _TSuperclass >
+fpa::Base::MinimumSpanningTree< _TVertex, _TPath, _TSuperclass >::
 MinimumSpanningTree( )
   : Superclass( )
 {
 }
 
 // -------------------------------------------------------------------------
-template< class V, class C, class B >
-fpa::Base::MinimumSpanningTree< V, C, B >::
+template< class _TVertex, class _TPath, class _TSuperclass >
+fpa::Base::MinimumSpanningTree< _TVertex, _TPath, _TSuperclass >::
 ~MinimumSpanningTree( )
 {
 }
 
-// -------------------------------------------------------------------------
-template< class V, class C, class B >
-void fpa::Base::MinimumSpanningTree< V, C, B >::
-_Path( std::vector< V >& path, const V& a ) const
-{
-  typename TDecorated::const_iterator dIt = this->Get( ).find( a );
-  if( dIt != this->Get( ).end( ) )
-  {
-    do
-    {
-      path.push_back( dIt->first );
-      dIt = this->Get( ).find( dIt->second.first );
-
-    } while( dIt->first != dIt->second.first && dIt != this->Get( ).end( ) );
-
-    if( dIt != this->Get( ).end( ) )
-      path.push_back( dIt->first );
-
-  } // fi
-}
-
-#endif // __FPA__BASE__MINIMUMSPANNINGTREE__HXX__
+#endif // __fpa__Base__MinimumSpanningTree__hxx__
 
 // eof - $RCSfile$