Initial version of Cgraph created.

diff --git a/lib/cgraph/flatten.c b/lib/cgraph/flatten.c
new file mode 100644 (file)
index 0000000..6e09077
--- /dev/null
+++ b/lib/cgraph/flatten.c
@@ -0,0 +1,44 @@
+#include "cghdr.h"
+
+static void agflatten_elist(Dict_t * d, Dtlink_t ** lptr)
+{
+    dtrestore(d, *lptr);
+    (void) dtflatten(d);
+    *lptr = dtextract(d);
+}
+
+void agflatten_edges(Agraph_t * g, Agnode_t * n)
+{
+    Agsubnode_t *sn;
+    Dtlink_t **tmp;
+
+       sn = agsubrep(g,n);
+    tmp = &(sn->out_seq); /* avoiding - "dereferencing type-punned pointer will break strict-aliasing rules" */
+    agflatten_elist(g->e_seq, tmp);
+    tmp = &(sn->in_seq);
+    agflatten_elist(g->e_seq, tmp);
+}
+
+void agflatten(Agraph_t * g, int flag)
+{
+    Agnode_t *n;
+
+    if (flag) {
+       if (g->desc.flatlock == FALSE) {
+           dtflatten(g->n_seq);
+           g->desc.flatlock = TRUE;
+           for (n = agfstnode(g); n; n = agnxtnode(g,n))
+               agflatten_edges(g, n);
+       }
+    } else {
+       if (g->desc.flatlock) {
+           g->desc.flatlock = FALSE;
+       }
+    }
+}
+
+void agnotflat(Agraph_t * g)
+{
+    if (g->desc.flatlock)
+       agerr(AGERR, "flat lock broken");
+}