Programming GPS and OpenStreetMap Applications with Java

128 9. Navigating Objects

from the origin over all moves and retrieve one node for every move. As

soon as a queue is empty, the next one is filled until they are all used up.

Sometimes a look at the data (structures) is more helpful than the pseu-

docode. The graph is transformed into a tree view from the origin’s per-

spective:

graph -> tree view -> collection view -> move loop

currPath[] queues[]

origin: 1 move#: 1 2 3 [0] = origin

move# / | \ : 1 2 5 11 [1] = [0]

1 2 3 4 currPath 1 2 6 X :

/| / \ |\ : 1 3 7 12 [2] = [1]

2 5 6 7 8 9 10 : : : : : :

| / \ | | \ : 1 4 10 16 [moves] =

3 11 12 13 14 15 16 path [0][1][2][3] [moves-1]

The GameMap implementation ...