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Support multi starts/ends in the Dijkstra pathfinding engine. [rebuild] [release]

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This commit is contained in:
Dustin Carlino 2021-07-11 10:11:50 -07:00
parent 7b98dd72e2
commit 843dd38f7e
1 changed files with 26 additions and 9 deletions
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35
map_model/src/pathfind/engine.rs
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@ -38,15 +38,32 @@ impl PathfindEngine {
match self {
PathfindEngine::Empty => unreachable!(),
PathfindEngine::Dijkstra { ref graph } => {
// TODO Handle multiple sources/targets by brute-force
let end = NodeIndex::new(ends[0].0);
let (raw_weight, raw_nodes) = petgraph::algo::astar(
graph,
NodeIndex::new(starts[0].0),
|node| node == end,
|edge| *edge.weight(),
|_| 0,
)?;
// If there are multiple starts and ends, calculate each individual path and take
// the lowest cost.
let mut best_pair: Option<(usize, Vec<NodeIndex>)> = None;
for (start_node, weight1) in starts {
let start_node = NodeIndex::new(start_node);
for (end_node, weight2) in &ends {
let end_node = NodeIndex::new(*end_node);
if let Some((raw_weight, raw_nodes)) = petgraph::algo::astar(
graph,
start_node,
|node| node == end_node,
|edge| *edge.weight(),
|_| 0,
) {
let total_weight = raw_weight + weight1 + weight2;
if best_pair
.as_ref()
.map(|pair| total_weight < pair.0)
.unwrap_or(true)
{
best_pair = Some((total_weight, raw_nodes));
}
}
}
}
let (raw_weight, raw_nodes) = best_pair?;
Some((
raw_weight,
raw_nodes.into_iter().map(|n| n.index()).collect(),