public void SutherLandHodgmanTest()
{
////a 5 sided polyline
var clip = Create.Polyline(new List <Point> {
Create.Point(0.15127, 1.985252, 0),
Create.Point(2.390837, 4.912972, 0),
Create.Point(6.715149, 7.422141, 0),
Create.Point(13.361243, 1.555223, 0),
Create.Point(6.021124, -1.413337, 0),
Create.Point(0.15127, 1.985252, 0),
});
//a W shaped polyline
var subject = Create.Polyline(new List <Point> {
Create.Point(4.468621, -0.202845, 0),
Create.Point(4.253897, 0.574251, 0),
Create.Point(4.039173, 1.351347, 0),
Create.Point(3.463167, 3.440645, 0),
Create.Point(2.887162, 5.529943, 0),
Create.Point(2.253215, 5.529943, 0),
Create.Point(1.619268, 5.529943, 0),
Create.Point(2.726971, 1.910311, 0),
Create.Point(3.834674, -1.709321, 0),
Create.Point(4.475437, -1.709321, 0),
Create.Point(5.116201, -1.709321, 0),
Create.Point(5.848989, 1.075274, 0),
Create.Point(6.581777, 3.859868, 0),
Create.Point(6.721518, 3.242963, 0),
Create.Point(6.861259, 2.626058, 0),
Create.Point(7.437264, 0.458369, 0),
Create.Point(8.01327, -1.709321, 0),
Create.Point(8.650625, -1.709321, 0),
Create.Point(9.28798, -1.709321, 0),
Create.Point(10.419541, 1.910311, 0),
Create.Point(11.551102, 5.529943, 0),
Create.Point(10.954647, 5.529943, 0),
Create.Point(10.358191, 5.529943, 0),
Create.Point(9.737878, 3.437237, 0),
Create.Point(9.117564, 1.344531, 0),
Create.Point(8.909657, 0.645826, 0),
Create.Point(8.701749, -0.052879, 0),
Create.Point(8.521109, 0.639009, 0),
Create.Point(8.340468, 1.330897, 0),
Create.Point(7.798546, 3.43042, 0),
Create.Point(7.256623, 5.529943, 0),
Create.Point(6.626085, 5.529943, 0),
Create.Point(5.995546, 5.529943, 0),
Create.Point(5.419541, 3.40997, 0),
Create.Point(4.843535, 1.289998, 0),
Create.Point(4.495887, -0.086962, 0),
Create.Point(4.468621, -0.202845, 0)
});
//the expected result
var expectedresult = Create.Polyline(new List <Point> {
Create.Point(4.843535, 1.289998, 0),
Create.Point(4.495887, -0.086962, 0),
Create.Point(4.468621, -0.202845, 0),
Create.Point(4.253897, 0.574251, 0),
Create.Point(4.039173, 1.351347, 0),
Create.Point(3.502262, 3.29884, 0),
Create.Point(2.965352, 5.246332, 0),
Create.Point(2.678094, 5.079652, 0),
Create.Point(2.390837, 4.912972, 0),
Create.Point(2.182718, 4.640903, 0),
Create.Point(1.974598, 4.368835, 0),
Create.Point(2.614177, 2.278889, 0),
Create.Point(3.253755, 0.188943, 0),
Create.Point(4.278598, -0.404431, 0),
Create.Point(5.303442, -0.997806, 0),
Create.Point(5.942609, 1.431031, 0),
Create.Point(6.581777, 3.859868, 0),
Create.Point(6.721518, 3.242963, 0),
Create.Point(6.861259, 2.626058, 0),
Create.Point(7.305098, 0.95575, 0),
Create.Point(7.748938, -0.714558, 0),
Create.Point(8.807826, -0.286312, 0),
Create.Point(9.866715, 0.141933, 0),
Create.Point(10.417745, 1.904568, 0),
Create.Point(10.968776, 3.667202, 0),
Create.Point(10.507983, 4.073972, 0),
Create.Point(10.04719, 4.480742, 0),
Create.Point(9.582377, 2.912637, 0),
Create.Point(9.117564, 1.344531, 0),
Create.Point(8.909657, 0.645826, 0),
Create.Point(8.701749, -0.052879, 0),
Create.Point(8.521109, 0.639009, 0),
Create.Point(8.340468, 1.330897, 0),
Create.Point(7.798546, 3.43042, 0),
Create.Point(7.256623, 5.529943, 0),
Create.Point(6.626085, 5.529943, 0),
Create.Point(5.995546, 5.529943, 0),
Create.Point(5.419541, 3.40997, 0),
Create.Point(4.843535, 1.289998, 0)
});
var expectedArea = expectedresult.Area();
var result = Compute.ClipPolylines(subject, clip);
var area = result.Area();
var areadiff = Math.Abs(area - expectedArea) / expectedArea;
if (areadiff > 0.001)
{
//for the avalue 0.1% is probably good enough
throw new Exception("Incorrect result from SutherLandHodgman test");
}
//get the points in a file for a visual compare
using (StreamWriter writer = new StreamWriter("points.txt"))
{
foreach (Point p in result.ControlPoints)
{
writer.WriteLine(string.Format("{{{0:0.000000},{1:0.000000},0}}", p.X, p.Y));
}
}
}