Improving network visualization in show/&show.

src/aig/aig/aigShow.c

@@ -47,7 +47,7 @@ void Aig_WriteDotAig( Aig_Man_t * pMan, char * pFileName, int fHaig, Vec_Ptr_t *
 {
     FILE * pFile;
     Aig_Obj_t * pNode;//, * pTemp, * pPrev;
-    int LevelMax, Level, i;
+    int LevelMax, Prev, Level, i;
 
     if ( Aig_ManNodeNum(pMan) > 200 )
     {
@@ -252,6 +252,14 @@ void Aig_WriteDotAig( Aig_Man_t * pMan, char * pFileName, int fHaig, Vec_Ptr_t *
     fprintf( pFile, "title1 -> title2 [style = invis];\n" );
     Aig_ManForEachCo( pMan, pNode, i )
         fprintf( pFile, "title2 -> Node%d [style = invis];\n", pNode->Id );
+    // generate invisible edges among the COs
+    Prev = -1;
+    Aig_ManForEachCo( pMan, pNode, i )
+    {
+        if ( i > 0 )
+            fprintf( pFile, "Node%d -> Node%d [style = invis];\n", Prev, pNode->Id );
+        Prev = pNode->Id;
+    }
 
     // generate edges
     Aig_ManForEachObj( pMan, pNode, i )

src/base/io/ioWriteDot.c

@@ -73,7 +73,7 @@ void Io_WriteDotNtk( Abc_Ntk_t * pNtk, Vec_Ptr_t * vNodes, Vec_Ptr_t * vNodesSho
     FILE * pFile;
     Abc_Obj_t * pNode, * pFanin;
     char * pSopString;
-    int LevelMin, LevelMax, fHasCos, Level, i, k, fHasBdds, fCompl;
+    int LevelMin, LevelMax, fHasCos, Level, i, k, fHasBdds, fCompl, Prev;
     int Limit = 300;
 
     assert( Abc_NtkIsStrash(pNtk) || Abc_NtkIsLogic(pNtk) );
@@ -365,6 +365,18 @@ void Io_WriteDotNtk( Abc_Ntk_t * pNtk, Vec_Ptr_t * vNodes, Vec_Ptr_t * vNodesSho
             continue;
         fprintf( pFile, "title2 -> Node%d [style = invis];\n", pNode->Id );
     }
+    // generate invisible edges among the COs
+    Prev = -1;
+    Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pNode, i )
+    {
+        if ( (int)pNode->Level != LevelMax )
+            continue;
+        if ( !Abc_ObjIsPo(pNode) )
+            continue;
+        if ( Prev >= 0 )
+            fprintf( pFile, "Node%d -> Node%d [style = invis];\n", Prev, pNode->Id );
+        Prev = pNode->Id;
+    }
 
     // generate edges
     Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pNode, i )
@@ -424,7 +436,7 @@ void Io_WriteDotSeq( Abc_Ntk_t * pNtk, Vec_Ptr_t * vNodes, Vec_Ptr_t * vNodesSho
     FILE * pFile;
     Abc_Obj_t * pNode, * pFanin;
     char * pSopString;
-    int LevelMin, LevelMax, fHasCos, Level, i, k, fHasBdds, fCompl;
+    int LevelMin, LevelMax, fHasCos, Level, i, k, fHasBdds, fCompl, Prev;
     int Limit = 300;
 
     assert( Abc_NtkIsStrash(pNtk) || Abc_NtkIsLogic(pNtk) );
@@ -713,6 +725,18 @@ void Io_WriteDotSeq( Abc_Ntk_t * pNtk, Vec_Ptr_t * vNodes, Vec_Ptr_t * vNodesSho
             continue;
         fprintf( pFile, "title2 -> Node%d [style = invis];\n", pNode->Id );
     }
+    // generate invisible edges among the COs
+    Prev = -1;
+    Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pNode, i )
+    {
+        if ( (int)pNode->Level != LevelMax )
+            continue;
+        if ( !Abc_ObjIsPo(pNode) )
+            continue;
+        if ( Prev >= 0 )
+            fprintf( pFile, "Node%d -> Node%d [style = invis];\n", Prev, pNode->Id );
+        Prev = pNode->Id;
+    }
 
     // generate edges
     Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pNode, i )