/// <summary>
/// Reads a LineString or multiple LineString geometries using the specified reader.
/// </summary>
/// <typeparam name="TMultipoint"></typeparam>
/// <typeparam name="TLinestring"></typeparam>
/// <typeparam name="TPoint"></typeparam>
/// <param name="reader"></param>
/// <param name="geometryType"></param>
/// <param name="ordinates"></param>
/// <param name="geometryBuilder"></param>
/// <returns></returns>
protected static IEnumerable <TLinestring> ReadLinestrings <TMultipoint, TLinestring, TPoint>(
[NotNull] BinaryReader reader,
WkbGeometryType geometryType,
Ordinates ordinates,
[NotNull] GeometryBuilderBase <TMultipoint, TLinestring, TPoint> geometryBuilder)
{
IEnumerable <TLinestring> linestrings;
if (geometryType == WkbGeometryType.MultiLineString ||
geometryType == WkbGeometryType.Polygon ||
geometryType == WkbGeometryType.MultiPolygon)
{
linestrings =
ReadLinestrings(reader, ordinates, geometryBuilder);
}
else if (geometryType == WkbGeometryType.LineString)
{
TLinestring linestring = ReadLinestringCore(reader, ordinates, geometryBuilder);
linestrings = new[] { linestring };
}
else
{
throw new NotSupportedException(
$"Cannot read {geometryType} as lineString or multiple lineStrings.");
}
return(linestrings);
}
/// <summary>
/// Reads multiple (>1) line strings, including the initial count.
/// </summary>
/// <typeparam name="TMultipoint"></typeparam>
/// <typeparam name="TLinestring"></typeparam>
/// <typeparam name="TPoint"></typeparam>
/// <param name="reader"></param>
/// <param name="ordinates"></param>
/// <param name="geometryBuilder"></param>
/// <returns></returns>
private static IEnumerable <TLinestring> ReadLinestrings <TMultipoint, TLinestring, TPoint>(
[NotNull] BinaryReader reader,
Ordinates ordinates,
[NotNull] GeometryBuilderBase <TMultipoint, TLinestring, TPoint> geometryBuilder)
{
int linestringCount = checked ((int)reader.ReadUInt32());
return(ReadLinestrings(reader, ordinates, linestringCount, geometryBuilder));
}
private static L ReadLinestringCore <L, P>(BinaryReader reader, Ordinates ordinates,
GeometryBuilderBase <L, P> geometryBuilder)
{
int pointCount = checked ((int)reader.ReadUInt32());
IPointFactory <P> builder = geometryBuilder.GetPointFactory(ordinates);
return(geometryBuilder.CreateLinestring(
ReadPointsCore(reader, ordinates, builder, pointCount), pointCount));
}
protected static IEnumerable <L> ReadLinestringsCore <L, P>(
[NotNull] BinaryReader reader,
Ordinates ordinates,
int linestringCount,
[NotNull] GeometryBuilderBase <L, P> geometryBuilder)
{
for (int i = 0; i < linestringCount; i++)
{
yield return(ReadLinestringCore(reader, ordinates, geometryBuilder));
}
}
protected static TMultipoint ReadMultipointCore <TMultipoint, TLinestring, TPoint>(
[NotNull] BinaryReader reader,
Ordinates ordinates,
int pointCount,
[NotNull] GeometryBuilderBase <TMultipoint, TLinestring, TPoint> geometryBuilder)
{
IPointFactory <TPoint> builder = geometryBuilder.GetPointFactory(ordinates);
const bool reReadPointTypes = true;
IEnumerable <TPoint> readPointsCore =
ReadPointsCore(reader, ordinates, builder, pointCount, reReadPointTypes);
return(geometryBuilder.CreateMultipoint(readPointsCore, pointCount));
}
/// <summary>
/// Reads multiple (>1) line strings, without the initial count.
/// </summary>
/// <typeparam name="TMultipoint"></typeparam>
/// <typeparam name="TLinestring"></typeparam>
/// <typeparam name="TPoint"></typeparam>
/// <param name="reader"></param>
/// <param name="expectedOrdinates"></param>
/// <param name="linestringCount"></param>
/// <param name="geometryBuilder"></param>
/// <returns></returns>
private static IEnumerable <TLinestring> ReadLinestrings <TMultipoint, TLinestring, TPoint>(
[NotNull] BinaryReader reader,
Ordinates expectedOrdinates,
int linestringCount,
[NotNull] GeometryBuilderBase <TMultipoint, TLinestring, TPoint> geometryBuilder)
{
for (int i = 0; i < linestringCount; i++)
{
ReadWkbType(reader, false,
out WkbGeometryType geometryType, out Ordinates ordinates);
Assert.AreEqual(WkbGeometryType.LineString, geometryType,
"Unexpected geometry type");
Assert.AreEqual(expectedOrdinates, ordinates,
"Linestring with inconsistent ordinates encountered.");
yield return(ReadLinestringCore(reader, ordinates, geometryBuilder));
}
}
