public SpriteGeneratorSearchNode SearchStep(SpriteGeneratorSearchProblem problem)
{
// If the fringe is empty, return null to indicate that no solution was found
if (fringe.Empty)
{
return(null);
}
// Select the next node
var node = fringe.Remove();
// If the node is a solution, then we're done! Otherwise expand the node and add to the queue
if (!problem.IsGoal(node.State))
{
AddNodes(fringe, node, problem);
}
// Return the node that we selected to the caller
return(node);
}
