I am storing some location data in Azure CosmosDB as following:
{
...
"Polygon": {
"type": "Polygon",
"coordinates": [
[
-72.2811341,
42.9275741
],
[
-72.2816062,
42.9256955
],
[
-72.2780764,
42.9261986
],
[
-72.2811341,
42.9275741
]
]
},
...
}
I want to check if a particular Point is inside this polygon, but the polygon can have multiple rings inside it. I am using the following code to check if a point is inside a single ring polygon:
private bool IsPointInPolygon(Point p, Position[] polygon)
{
double minX = polygon[0].Latitude;
double maxX = polygon[0].Latitude;
double minY = polygon[0].Longitude;
double maxY = polygon[0].Longitude;
for (int i = 1; i < polygon.Length; i++)
{
Position q = polygon[i];
minX = Math.Min(q.Latitude, minX);
maxX = Math.Max(q.Latitude, maxX);
minY = Math.Min(q.Longitude, minY);
maxY = Math.Max(q.Longitude, maxY);
}
if (p.Position.Latitude < minX || p.Position.Latitude > maxX || p.Position.Longitude < minY || p.Position.Longitude > maxY)
{
return false;
}
bool inside = false;
for (int i = 0, j = polygon.Length - 1; i < polygon.Length; j = i++)
{
if ((polygon[i].Longitude > p.Position.Longitude) != (polygon[j].Longitude > p.Position.Longitude) &&
p.Position.Latitude < (polygon[j].Latitude - polygon[i].Latitude) * (p.Position.Longitude - polygon[i].Longitude) / (polygon[j].Longitude - polygon[i].Longitude) + polygon[i].Latitude)
{
inside = !inside;
}
}
return inside;
}
Is there a way that I can modify this method to check for multiple rings in polygon which means the first ring is the outer ring and the others basically exclude areas inside this outer ring?
