int
shortPath (sgraph* g, snode* from, snode* to)
{
snode* n;
sedge* e;
snode* adjn;
int d;
int x, y;
for (x = 0; x<g->nnodes; x++) {
snode* temp;
temp = &(g->nodes[x]);
N_VAL(temp) = UNSEEN;
}
PQinit();
if (PQ_insert (from)) return 1;
N_DAD(from) = NULL;
N_VAL(from) = 0;
while ((n = PQremove())) {
#ifdef DEBUG
fprintf (stderr, "process %d\n", n->index);
#endif
N_VAL(n) *= -1;
if (n == to) break;
for (y=0; y<n->n_adj; y++) {
e = &(g->edges[n->adj_edge_list[y]]);
adjn = adjacentNode(g, e, n);
if (N_VAL(adjn) < 0) {
d = -(N_VAL(n) + E_WT(e));
if (N_VAL(adjn) == UNSEEN) {
#ifdef DEBUG
fprintf (stderr, "new %d (%d)\n", adjn->index, -d);
#endif
N_VAL(adjn) = d;
if (PQ_insert(adjn)) return 1;
N_DAD(adjn) = n;
N_EDGE(adjn) = e;
}
else {
if (N_VAL(adjn) < d) {
#ifdef DEBUG
fprintf (stderr, "adjust %d (%d)\n", adjn->index, -d);
#endif
PQupdate(adjn, d);
N_DAD(adjn) = n;
N_EDGE(adjn) = e;
}
}
}
}
}
/* PQfree(); */
return 0;
}
static route
convertSPtoRoute (sgraph* g, snode* fst, snode* lst)
{
route rte;
snode* ptr;
snode* next;
snode* prev; /* node in shortest path just previous to next */
int i, sz = 0;
cell* cp;
cell* ncp;
segment seg;
double fix, b1, b2;
int l1, l2;
pointf bp1, bp2, prevbp; /* bend points */
/* count no. of nodes in shortest path */
for (ptr = fst; ptr; ptr = N_DAD(ptr)) sz++;
rte.n = 0;
rte.segs = N_NEW(sz-2, segment); /* at most sz-2 segments */
seg.prev = seg.next = 0;
ptr = prev = N_DAD(fst);
next = N_DAD(ptr);
if (IsNode(ptr->cells[0]))
cp = ptr->cells[1];
else
cp = ptr->cells[0];
bp1 = sidePt (ptr, cp);
while (N_DAD(next)!=NULL) {
ncp = cellOf (prev, next);
updateWts (g, ncp, N_EDGE(ptr));
/* add seg if path bends or at end */
if ((ptr->isVert != next->isVert) || (N_DAD(next) == lst)) {
if (ptr->isVert != next->isVert)
bp2 = midPt (ncp);
else
bp2 = sidePt(next, ncp);
if (ptr->isVert) { /* horizontal segment */
if (ptr == N_DAD(fst)) l1 = B_NODE;
else if (prevbp.y > bp1.y) l1 = B_UP;
else l1 = B_DOWN;
if (ptr->isVert != next->isVert) {
if (next->cells[0] == ncp) l2 = B_UP;
else l2 = B_DOWN;
}
else l2 = B_NODE;
fix = cp->bb.LL.y;
b1 = cp->bb.LL.x;
b2 = ncp->bb.LL.x;
}
else { /* vertical segment */
if (ptr == N_DAD(fst)) l1 = B_NODE;
else if (prevbp.x > bp1.x) l1 = B_RIGHT;
else l1 = B_LEFT;
if (ptr->isVert != next->isVert) {
if (next->cells[0] == ncp) l2 = B_RIGHT;
else l2 = B_LEFT;
}
else l2 = B_NODE;
fix = cp->bb.LL.x;
b1 = cp->bb.LL.y;
b2 = ncp->bb.LL.y;
}
setSeg (&seg, !ptr->isVert, fix, b1, b2, l1, l2);
rte.segs[rte.n++] = seg;
cp = ncp;
prevbp = bp1;
bp1 = bp2;
if ((ptr->isVert != next->isVert) && (N_DAD(next) == lst)) {
bp2 = sidePt(next, ncp);
l2 = B_NODE;
if (next->isVert) { /* horizontal segment */
if (prevbp.y > bp1.y) l1 = B_UP;
else l1 = B_DOWN;
fix = cp->bb.LL.y;
b1 = cp->bb.LL.x;
b2 = ncp->bb.LL.x;
}
else {
if (prevbp.x > bp1.x) l1 = B_RIGHT;
else l1 = B_LEFT;
fix = cp->bb.LL.x;
b1 = cp->bb.LL.y;
b2 = ncp->bb.LL.y;
}
setSeg (&seg, !next->isVert, fix, b1, b2, l1, l2);
rte.segs[rte.n++] = seg;
}
ptr = next;
}
prev = next;
next = N_DAD(next);
}
rte.segs = realloc (rte.segs, rte.n*sizeof(segment));
for (i=0; i<rte.n; i++) {
if (i > 0)
rte.segs[i].prev = rte.segs + (i-1);
if (i < rte.n-1)
rte.segs[i].next = rte.segs + (i+1);
}
return rte;
}
