private async Task BuildNodeGraph(float regionRadius, float bodyRadius, float toleranceRadius, CancellationToken cancellation)
{
this.regionRadius = Mathf.Max(regionRadius, 0);
this.bodyRadius = Mathf.Max(bodyRadius, 0);
cancellation.ThrowIfCancellationRequested();
// Build stencil.
var stencil = await VisionStencil.BuildAsync(regionRadius, bodyRadius, toleranceRadius);
cancellation.ThrowIfCancellationRequested();
// Build vision edges.
int visionMaxOffset = Mathf.FloorToInt(regionRadius);
var tasks = new List <Task>();
foreach (var node in nodes)
{
if (node is null)
{
continue;
}
var currentNode = node;
var task = Task.Run(() => {
// See all nodes around current one; add edge in graph for every visible node.
foreach (var destinationPosition in Enumerables.InSegment2(
currentNode.Position - visionMaxOffset * Vector2Int.one, currentNode.Position + visionMaxOffset * Vector2Int.one))
{
cancellation.ThrowIfCancellationRequested();
if (!Enumerables.IsIndex(destinationPosition, nodes))
{
continue;
}
var visionPath = stencil.GetVisionPath(currentNode.Position, destinationPosition);
if (visionPath is null)
{
continue;
}
bool visible = true;
foreach (var passedPosition in visionPath)
{
var passedNode = nodes[passedPosition.x, passedPosition.y];
if (passedNode is null)
{
visible = false;
break;
}
}
if (visible)
{
var destinationNode = nodes[destinationPosition.x, destinationPosition.y];
currentNode.AddVisible(destinationNode);
}
}
});
tasks.Add(task);
cancellation.ThrowIfCancellationRequested();
}
await Task.WhenAll(tasks);
cancellation.ThrowIfCancellationRequested();
// Build reach edges.
tasks.Clear();
foreach (var node in nodes)
{
if (node is null)
{
continue;
}
var currentNode = node;
var task = Task.Run(() => {
// Try reach all nodes around current one; add edge in graph for every reachable node.
var reachable = DijkstraDense.FindAllReachable(currentNode.AsVision, regionRadius);
cancellation.ThrowIfCancellationRequested();
foreach (var nodeAndDistance in reachable)
{
var reachedPosition = nodeAndDistance.Key.Position;
var reachedNode = nodes[reachedPosition.x, reachedPosition.y];
currentNode.AddReachable(reachedNode, nodeAndDistance.Value);
}
cancellation.ThrowIfCancellationRequested();
});
tasks.Add(task);
cancellation.ThrowIfCancellationRequested();
}
await Task.WhenAll(tasks);
cancellation.ThrowIfCancellationRequested();
}
