public void TestSTUnaryUnion()
{
using (var db = new PostGisTestDataConnection(TestDatabaseConnectionString))
{
const string Wkt1 = "POLYGON((0 1, 0 3, 2 3, 2 1, 0 1))";
const string Wkt2 = "POLYGON((1 0, 1 2, 3 2, 3 0, 1 0))";
db.TestGeometries
.Value(g => g.Id, 1)
.Value(g => g.Geometry, () => GeometryInput.STGeomFromText(Wkt1, SRID4326))
.Insert();
db.TestGeometries
.Value(g => g.Id, 2)
.Value(g => g.Geometry, () => GeometryInput.STGeomFromText(Wkt2, SRID4326))
.Insert();
var result1 = db.TestGeometries
.Select(g => GeometryConstructors.STCollect(
db.TestGeometries.Where(g1 => g1.Id == 1).Single().Geometry,
db.TestGeometries.Where(g2 => g2.Id == 2).Single().Geometry)
.STUnaryUnion())
.First() as NTSGS.Polygon;
// "POLYGON((1 0,1 1,0 1,0 3,2 3,2 2,3 2,3 0,1 0))"
Assert.IsNotNull(result1);
Assert.AreEqual(9, result1.Coordinates.Length);
var result2 = db.Select(() => OverlayFunctions.STUnaryUnion("MULTIPOLYGON(((0 1,0 3,2 3,2 1,0 1)),((1 0,1 2,3 2,3 0,1 0)))")) as NTSGS.Polygon;
Assert.IsNotNull(result2);
Assert.AreEqual(9, result2.Coordinates.Length);
Assert.IsNull(db.Select(() => OverlayFunctions.STUnaryUnion((NTSG)null)));
}
}
public void TestSTClipByBox2D()
{
using (var db = new PostGisTestDataConnection(TestDatabaseConnectionString))
{
var geom1 = db.Select(() => GeometryInput.STGeomFromText("LINESTRING(0 0, 20 20)"));
var box1 = db.Select(() => GeometryConstructors.STMakeEnvelope(0, 0, 10, 10));
var clipped1 = db.Select(() => OverlayFunctions.STClipByBox2D(geom1, box1).STAsText());
Assert.AreEqual("LINESTRING(0 0,10 10)", clipped1);
Assert.IsNull(db.Select(() => OverlayFunctions.STClipByBox2D(null, null)));
}
}
public void TestSTTransformText()
{
using (var db = new PostGisTestDataConnection(TestDatabaseConnectionString))
{
const string Gnom = "+proj=gnom +ellps=WGS84 +lat_0=70 +lon_0=-160 +no_defs";
const string Wkt1 = "POLYGON((170 50,170 72,-130 72,-130 50,170 50))";
const string Wkt2 = "POLYGON((-170 68,-170 90,-141 90,-141 68,-170 68))";
db.TestGeometries
.Value(g => g.Id, 1)
.Value(g => g.Geometry, () => GeometryInput.STGeomFromText(Wkt1, SRID4326))
.Insert();
db.TestGeometries
.Value(g => g.Id, 2)
.Value(g => g.Geometry, () => GeometryInput.STGeomFromText(Wkt2, SRID4326))
.Insert();
var result = db.TestGeometries
.Select(g => OverlayFunctions
.STIntersection(
db.TestGeometries.Where(g1 => g1.Id == 1).Single().Geometry.STTransform(Gnom),
db.TestGeometries.Where(g2 => g2.Id == 2).Single().Geometry.STTransform(Gnom))
.STTransform(Gnom, SRID4326))
.First() as NTSGS.Polygon;
var expected = new double[][]
{
new[] { -170, 74.053793645338 },
new[] { -141, 73.4268621378904 },
new[] { -141, 68.0 },
new[] { -170, 68.0 },
new[] { -170, 74.053793645338 },
};
Assert.AreEqual(expected.Length, result.Coordinates.Length);
// TODO: order of vertices depends on PostGIS version
////for (var i = 0; i < expected.Length; i++)
////{
//// Assert.AreEqual(expected[i][0], result.Coordinates[i].X, 1.0E-12);
//// Assert.AreEqual(expected[i][1], result.Coordinates[i].Y, 1.0E-12);
////}
}
}
