protected override CoordinateSequence TransformCoordinates(CoordinateSequence coords, Geometry parent)
{
var inputPts = coords.ToCoordinateArray();
Coordinate[] newPts;
if (inputPts.Length == 0)
{
newPts = new Coordinate[0];
}
else
{
newPts = VWLineSimplifier.Simplify(inputPts, _distanceTolerance);
}
return(Factory.CoordinateSequenceFactory.Create(newPts));
}
public void TestNewResultsIdenticalToOldResults()
{
// at 0.02, Simplify deletes about 50% of world.wkt points
const double DistanceTolerance = 0.02;
int pointsRemoved = 0;
int totalPointCount = 0;
// track how long the new takes compared to the old
long oldTicks = 0;
long newTicks = 0;
using (var file = EmbeddedResourceManager.GetResourceStream("NetTopologySuite.Tests.NUnit.TestData.world.wkt"))
{
foreach (LineString line in IOUtil.ReadWKTFile(new StreamReader(file)).SelectMany(LinearComponentExtracter.GetLines))
{
var coordinates = line.Coordinates;
var sw = Stopwatch.StartNew();
var oldResults = OldVWLineSimplifier.Simplify(coordinates, DistanceTolerance);
sw.Stop();
oldTicks += sw.ElapsedTicks;
sw.Restart();
var newResults = VWLineSimplifier.Simplify(coordinates, DistanceTolerance);
sw.Stop();
newTicks += sw.ElapsedTicks;
CollectionAssert.AreEqual(oldResults, newResults);
pointsRemoved += coordinates.Length - newResults.Length;
totalPointCount += coordinates.Length;
}
}
TestContext.WriteLine("Total: Removed {0} of {1} points (reduction: {2:P0}).", pointsRemoved, totalPointCount, pointsRemoved / (double)totalPointCount);
TestContext.WriteLine("Old: {0:N3} seconds. New: {1:N3} seconds (reduction: {2:P0}).", oldTicks / (double)Stopwatch.Frequency, newTicks / (double)Stopwatch.Frequency, (oldTicks - newTicks) / (double)oldTicks);
}
