/* initGraphAttrs:
* Set attributes based on original root graph.
* This is obtained by taking a node of g, finding its node
* in the original graph, and finding that node's graph.
*/
static void initGraphAttrs(Agraph_t * g, circ_state * state)
{
static Agraph_t *rootg;
static attrsym_t *N_artpos;
static attrsym_t *N_root;
static attrsym_t *G_mindist;
static char *rootname;
Agraph_t *rg;
node_t *n = agfstnode(g);
rg = agraphof(ORIGN(n));
if (rg != rootg) { /* new root graph */
state->blockCount = 0;
rootg = rg;
G_mindist = agattr(rootg,AGRAPH, "mindist", NULL);
N_artpos = agattr(rootg,AGNODE, "articulation_pos", NULL);
N_root = agattr(rootg,AGNODE, "root", NULL);
}
rootname = agget(rootg, "root");
initBlocklist(&state->bl);
state->orderCount = 1;
state->min_dist = late_double(rootg, G_mindist, MINDIST, 0.0);
state->N_artpos = N_artpos;
state->N_root = N_root;
state->rootname = rootname;
}
block_t *mkBlock(Agraph_t * g)
{
block_t *sn;
sn = NEW(block_t);
initBlocklist(&sn->children);
sn->sub_graph = g;
return sn;
}
/* create_block_tree:
* Construct block tree by peeling nodes from block list in state.
* When done, return root. The block list is empty
* FIX: use largest block as root
*/
block_t *createBlocktree(Agraph_t * g, circ_state * state)
{
block_t *bp;
block_t *next;
block_t *root;
int min;
/* int ordercnt; */
find_blocks(g, state);
bp = state->bl.first; /* if root chosen, will be first */
/* Otherwise, just pick first as root */
root = bp;
/* Find node with minimum VAL value to find parent block */
/* FIX: Should be some way to avoid search below. */
/* ordercnt = state->orderCount; */
for (bp = bp->next; bp; bp = next) {
Agnode_t *n;
Agnode_t *parent;
Agnode_t *child;
Agraph_t *subg = bp->sub_graph;
child = n = agfstnode(subg);
min = VAL(n);
parent = PARENT(n);
for (n = agnxtnode(subg, n); n; n = agnxtnode(subg, n)) {
if (VAL(n) < min) {
child = n;
min = VAL(n);
parent = PARENT(n);
}
}
SET_PARENT(parent);
CHILD(bp) = child;
next = bp->next; /* save next since list insertion destroys it */
appendBlock(&(BLOCK(parent)->children), bp);
}
initBlocklist(&state->bl); /* zero out list */
return root;
}
/* find_blocks:
*/
static void find_blocks(Agraph_t * g, circ_state * state)
{
Agnode_t *n;
Agnode_t *root = NULL;
block_t *rootBlock = NULL;
blocklist_t ublks;
#ifdef USER_BLOCKS
graph_t *clust_subg;
graph_t *mg;
edge_t *me;
node_t *mm;
int isRoot;
#endif
initBlocklist(&ublks);
/* check to see if there is a node which is set to be the root
*/
if (state->rootname) {
root = agfindnode(g, state->rootname);
}
if (!root && state->N_root) {
for (n = agfstnode(g); n; n = agnxtnode(g, n)) {
if (late_bool(ORIGN(n), state->N_root, 0)) {
root = n;
break;
}
}
}
#ifdef USER_BLOCKS
/* process clusters first */
/* by construction, all subgraphs are blocks and are non-empty */
mm = g->meta_node;
mg = mm->graph;
for (me = agfstout(mg, mm); me; me = agnxtout(mg, me)) {
block_t *block;
clust_subg = agusergraph(me->head);
isRoot = 0;
block = mkBlock(clust_subg);
/* block = makeBlock(g, state); */
for (n = agfstnode(clust_subg); n; n = agnxtnode(clust_subg, n)) {
if (!BCDONE(n)) { /* test not necessary if blocks disjoint */
SET_BCDONE(n);
BLOCK(n) = block;
if (n == root)
isRoot = 1;
}
}
if (isRoot) {
/* Assume blocks are disjoint, so don't check if rootBlock is
* already assigned.
*/
rootBlock = block;
insertBlock(&state->bl, block);
} else {
appendBlock(&state->bl, block);
}
}
ublks.first = state->bl.first;
ublks.last = state->bl.last;
#endif
if (!root)
root = agfstnode(g);
dfs(g, root, state, !rootBlock);
#ifdef USER_BLOCKS
/* If g has user-supplied blocks, it may be disconnected.
* We then fall into the following ugly loop.
* We are guaranteed !VISITED(n) and PARENT(n) has been
* set to a visited node.
*/
if (ublks.first) {
while (n = findUnvisited(&ublks)) {
dfs(g, n, state, 0);
}
}
#endif
}
