private static (float extraDistance, float percentageAlongRoute) ExtraDistanceIncurred(
GalacticSystem systemA, GalacticSystem systemB, GalacticPOI poi, float originalDistance)
{
var a = systemA.Coordinates;
var b = systemB.Coordinates;
var p = poi.Coordinates;
var aToPOI = System.Numerics.Vector3.Distance(a, p);
if (a == b)
{
return(aToPOI, 0f);
}
// Find the closest point to the POI along the straight line route, expressed as 0 (closest to a) to 1 (closest to b).
float distanceSquared = originalDistance * originalDistance;
float distanceAlongRoute = Math.Max(0f, Math.Min(1f, System.Numerics.Vector3.Dot(p - a, b - a) / distanceSquared));
var bToPOI = System.Numerics.Vector3.Distance(b, p);
var distanceViaPOI = aToPOI + bToPOI;
var extraDistance = distanceViaPOI - originalDistance;
var approxPercentageAlongRoute = distanceAlongRoute * 100f;
return(extraDistance, approxPercentageAlongRoute);
}
public ScenicSuggestionResults GenerateSuggestions(
GalacticSystem from,
GalacticSystem to,
float acceptableExtraDistance)
{
if (DistanceFromSol(to.Coordinates) < bubbleIgnoreRadius && DistanceFromSol(from.Coordinates) < bubbleIgnoreRadius)
{
// Warn user that their trip is very close to Earth and we won't have any useful POI suggestions!
throw new TripWithinBubbleException();
}
var originalDistance = DistanceBetweenPoints(from, to);
var edsmSuggestions = SuggestionsForList(POIs.Where(p => (int)p.Type < 100));
var codexSuggestions = SuggestionsForList(POIs.Where(p => (int)p.Type >= 100));
return(new ScenicSuggestionResults()
{
StraightLineDistance = originalDistance,
Suggestions = edsmSuggestions.Concat(codexSuggestions).ToList()
});
List <ScenicSuggestion> SuggestionsForList(IEnumerable <GalacticPOI> pois)
{
return(pois.
Where(p => p.DistanceFromSol > bubbleIgnoreRadius). // Ignore the "bubble" of near-Earth POIs
Select(p =>
{
var result = ExtraDistanceIncurred(@from, to, p, originalDistance);
return new ScenicSuggestion(p, result.extraDistance, result.percentageAlongRoute);
}).
Where(ss => ss.ExtraDistance <= acceptableExtraDistance && ss.ExtraDistance > 0f).
OrderBy(ss => ss.ExtraDistance).
Take(MAX_SUGGESTIONS / 2).
ToList());
}
}
public async Task <ScenicSuggestionResults> GenerateSuggestions(
GalacticSystem from,
GalacticSystem to,
float acceptableExtraDistance)
{
var calculator = new ScenicSuggestionCalculator(await repository.GetPOIs(), repository.Systems, BUBBLE_IGNORE_RADIUS);
return(calculator.GenerateSuggestions(from, to, acceptableExtraDistance));
}
