private static Boolean ContainsAnyState(Dictionary<PathCriticalPoint, PointFunction> dict, Point p, GeometryCollection geom, int key)
{
foreach(var line in geom.LinesAttachedTo(p))
{
PathCriticalPoint state = new PathCriticalPoint(line, line.p1.Equals(p));
if(dict.ContainsKey(state) && dict[state].timings.ContainsKey(key))
{
return true;
}
}
return false;
}
private static Path BestOfAnyState(Dictionary<PathCriticalPoint, PointFunction> dict, Point p, GeometryCollection geom, int key)
{
Path best = null;
foreach (var line in geom.LinesAttachedTo(p))
{
PathCriticalPoint state = new PathCriticalPoint(line, line.p1.Equals(p));
if (dict.ContainsKey(state) && dict[state].timings.ContainsKey(key))
{
if(best==null || dict[state].timings[key].totalTime>best.totalTime)
{
best = dict[state].timings[key];
}
}
}
return best;
}
public static Path PathTo(BoundParticle start, Point end, GeometryCollection geometry, float accel, float gravity)
{
// construct a new critical point
Point newPoint = start.position();
Line line1 = new Line(newPoint, start.boundTo.p1);
Line line2 = new Line(newPoint, start.boundTo.p2);
geometry.Add(line1);
geometry.Add(line2);
geometry.Remove(start.boundTo);
Queue<PathCriticalPoint> bfs = new Queue<PathCriticalPoint>();
// map time function for two attached points
Dictionary<PathCriticalPoint, PointFunction> dict = new Dictionary<PathCriticalPoint, PointFunction>();
PathCriticalPoint state1 = new PathCriticalPoint(line1, true);
PathCriticalPoint state2 = new PathCriticalPoint(line2, true);
dict[state1] = new PointFunction(0);
dict[state2] = new PointFunction(0);
bfs.Enqueue(state1);
bfs.Enqueue(state2);
// bfs will simply search through steps, and will not continue a branch if it doesn't improve anything
while (bfs.Count > 0)
{
var head = bfs.Dequeue();
// TODO: currently not going back to previously visited points, as the logic isn't correct for it
var currPoint = head.firstPoint ? head.line.p1 : head.line.p2;
foreach (var nextLine in geometry.LinesAttachedTo(currPoint).Where(l => !l.Equals(head.line)))
{
var nextPoint = (nextLine.p1.Equals(currPoint)) ? nextLine.p2 : nextLine.p1;
var nextState = new PathCriticalPoint(nextLine, nextLine.p1.Equals(nextPoint));
PointFunction timings = new PointFunction(currPoint, nextPoint, dict[head], accel, gravity);
WorkWithTimings(end, geometry, bfs, dict, nextState, timings);
// also attempt to return along that path
var nextState2 = new PathCriticalPoint(nextLine, nextLine.p1.Equals(currPoint));
PointFunction timings2 = PointFunction.Return(currPoint, nextPoint, dict[head], accel, gravity);
WorkWithTimings(end, geometry, bfs, dict, nextState2, timings2);
}
}
Path answer = null;
if (ContainsAnyState(dict, end, geometry, 0))
{
answer = BestOfAnyState(dict, end, geometry, 0);
}
geometry.Remove(newPoint);
geometry.Add(start.boundTo);
return answer;
}
private static void WorkWithTimings(Point end, GeometryCollection geometry, Queue<PathCriticalPoint> bfs, Dictionary<PathCriticalPoint, PointFunction> dict, PathCriticalPoint nextState, PointFunction timings)
{
if (dict.ContainsKey(nextState))
{
double lowestChange = dict[nextState].improved(timings);
if (!double.IsInfinity(lowestChange))
{
if (!ContainsAnyState(dict, end, geometry, 0) || lowestChange < BestOfAnyState(dict, end, geometry, 0).totalTime)
{
bfs.Enqueue(nextState);
}
}
}
else
{
double lowestChange = (timings.timings.Count > 0) ? timings.timings.OrderBy(p => p.Value.totalTime).First().Value.totalTime : double.PositiveInfinity;
dict[nextState] = timings;
if (!ContainsAnyState(dict, end, geometry, 0) || lowestChange < BestOfAnyState(dict, end, geometry, 0).totalTime)
{
bfs.Enqueue(nextState);
}
}
}