private static GeoAPI.Geometries.IPolygon ReadPolygon(byte[] geom, ref int idx, bool isLittleEndian, GeoAPI.Geometries.IGeometryFactory factory)
{
var nRings = ReadUInt32(geom, ref idx, isLittleEndian);
if (nRings < 1 || nRings > Int32.MaxValue / (2 * 8))
{
throw new ApplicationException("Currupt SpatialLite geom");
}
List <GeoAPI.Geometries.ILineString> lineStrings = new List <GeoAPI.Geometries.ILineString>();
for (int i = 0; i < nRings; i++)
{
lineStrings.Add(ReadLineString(geom, ref idx, isLittleEndian, factory));
}
List <GeoAPI.Geometries.ILinearRing> holes = null;
var shell = factory.CreateLinearRing(lineStrings[0].Coordinates);
if (lineStrings.Count > 1)
{
holes = new List <GeoAPI.Geometries.ILinearRing>();
for (int i = 1; i < lineStrings.Count; i++)
{
holes.Add(factory.CreateLinearRing(lineStrings[i].Coordinates));
}
}
return(factory.CreatePolygon(shell, holes == null ? null : holes.ToArray()));
}
public static GeoAPI.Geometries.ILinearRing CreateRectangle(GeoAPI.Geometries.IGeometryFactory factory,
GeoAPI.Geometries.Coordinate leftTop, GeoAPI.Geometries.Coordinate rightBottom)
{
var pts = new[]
{
leftTop,
new GeoAPI.Geometries.Coordinate(rightBottom.X, leftTop.Y),
rightBottom,
new GeoAPI.Geometries.Coordinate(leftTop.X, rightBottom.Y),
leftTop
};
return(factory.CreateLinearRing(pts));
}
public static GeoAPI.Geometries.ILinearRing CreateEllipse(GeoAPI.Geometries.IGeometryFactory factory,
GeoAPI.Geometries.Coordinate center, System.Drawing.SizeF size, int segmentsPerQuadrant)
{
const double piHalf = System.Math.PI * 0.5d;
var step = piHalf / segmentsPerQuadrant;
var pts = new GeoAPI.Geometries.Coordinate[4 * segmentsPerQuadrant + 1];
var angle = 0d;
for (var i = 0; i < 4 * segmentsPerQuadrant; i++)
{
pts[i] = new GeoAPI.Geometries.Coordinate(center.X + System.Math.Cos(angle) * size.Width,
center.Y + System.Math.Sin(angle) * size.Height);
angle += step;
}
pts[pts.Length - 1] = pts[0];
return(factory.CreateLinearRing(pts));
}