# redef fun debug_a_star do return true
#end
+# Simple node with a name
class NamedNode
super Node
redef fun to_s do return "node:{name}"
end
+# Node with a name and position
+class PositionedNamedNode
+ super NamedNode
+
+ redef type N: PositionedNamedNode
+
+ var x: Int
+ var y: Int
+
+ init(graph: Graph[N, Link], name: String, x, y: Int)
+ do
+ super
+
+ self.x = x
+ self.y = y
+ end
+
+ redef fun to_s do return "{super}-at-({x},{y})"
+
+ fun dist_with(o: PositionedNamedNode): Int
+ do
+ var dx = o.x - x
+ var dy = o.y - y
+ var d2 = dx*dx + dy*dy
+ return d2.sqrt
+ end
+end
+
+# Link for nodes with a position
+class PositionedLink
+ super Link
+
+ redef type N: PositionedNamedNode
+end
+
+# Context for a graph with positions
+class PositionPathContext
+ super PathContext
+
+ redef type N: PositionedNamedNode
+ redef type L: PositionedLink
+
+ init(graph: Graph[N,L])
+ do
+ super
+
+ for l in graph.links do
+ var this_cost = cost(l)
+ if this_cost > worst_cost then worst_cost = this_cost
+ end
+ end
+
+ redef var worst_cost = 0
+
+ redef fun cost(link) do return link.from.dist_with(link.to)
+
+ redef fun is_blocked(link) do return false
+
+ redef fun heuristic_cost(a, b)
+ do
+ var cost = a.dist_with(b)
+ if cost > 100 then return 100
+ return cost
+ end
+
+ redef fun worst_heuristic_cost do return 100
+end
+
fun print_path(path: nullable Path[NamedNode]) do if path == null then
print "null path"
else
print_path(path)
end
+# "Big" weighted graph
+#
+# a -2- b -1- f -1- g
+# / / \ /
+# 3 1 4 1
+# / / \ /
+# c -3- d -8- e -2- h -2- i -3- j
+#
+fun case_weighted_big
+do
+ var graph = new Graph[NamedNode,WeightedLink]
+
+ var na = new NamedNode(graph, "a")
+ var nb = new NamedNode(graph, "b")
+ var nc = new NamedNode(graph, "c")
+ var nd = new NamedNode(graph, "d")
+ var ne = new NamedNode(graph, "e")
+ var nf = new NamedNode(graph, "f")
+ var ng = new NamedNode(graph, "g")
+ var nh = new NamedNode(graph, "h")
+ var ni = new NamedNode(graph, "i")
+ var nj = new NamedNode(graph, "j")
+
+ var lab = new WeightedLink(graph, na, nb, 2)
+ var lac = new WeightedLink(graph, na, nc, 3)
+ var lbd = new WeightedLink(graph, nb, nd, 1)
+ var lcd = new WeightedLink(graph, nc, nd, 3)
+ var lde = new WeightedLink(graph, nd, ne, 8)
+ var lbf = new WeightedLink(graph, nb, nf, 1)
+ var lfg = new WeightedLink(graph, nf, ng, 1)
+ var leh = new WeightedLink(graph, ne, nh, 2)
+ var lhi = new WeightedLink(graph, nh, ni, 2)
+ var lij = new WeightedLink(graph, ni, nj, 3)
+ var lfh = new WeightedLink(graph, nf, nh, 4)
+ var lgh = new WeightedLink(graph, ng, nh, 1)
+
+ var context = new WeightedPathContext(graph)
+
+ var path = na.path_to(nj, 100, context)
+ print_path(path)
+end
+
+# Double-edge graph with coordinates on nodes
+#
+# a--b--d--e
+# \ |
+# c------f
+#
+fun cases_with_positions_and_heuristic
+do
+ var graph = new Graph[PositionedNamedNode,PositionedLink]
+
+ var na = new PositionedNamedNode(graph, "a", 0, 0)
+ var nb = new PositionedNamedNode(graph, "b", 2, 0)
+ var nc = new PositionedNamedNode(graph, "c", 2, 2)
+ var nd = new PositionedNamedNode(graph, "d", 5, 0)
+ var ne = new PositionedNamedNode(graph, "e", 8, 0)
+ var nf = new PositionedNamedNode(graph, "f", 8, 2)
+
+ var lab = new PositionedLink(graph, na, nb)
+ var lac = new PositionedLink(graph, na, nc)
+ var lbd = new PositionedLink(graph, nb, nd)
+ var lde = new PositionedLink(graph, nd, ne)
+ var lef = new PositionedLink(graph, ne, nf)
+ var lcf = new PositionedLink(graph, nc, nf)
+
+ # inverted
+ var lba = new PositionedLink(graph, nb, na)
+ var lca = new PositionedLink(graph, nc, na)
+ var ldb = new PositionedLink(graph, nd, nb)
+ var led = new PositionedLink(graph, ne, nd)
+ var lfe = new PositionedLink(graph, nf, ne)
+ var lfc = new PositionedLink(graph, nf, nc)
+
+ var context = new PositionPathContext(graph)
+
+ print_path(na.path_to(nf, 100, context))
+ print_path(nf.path_to(na, 100, context))
+ print_path(nc.path_to(ne, 100, context))
+ print_path(nd.path_to(nc, 100, context))
+end
+
case_simple
case_failed
case_weighted
case_weighted_too_long
+case_weighted_big
+cases_with_positions_and_heuristic