public virtual void TestCreation1()
{
// Simple area and length calcul test
com.esri.core.geometry.Polygon poly = new com.esri.core.geometry.Polygon();
int number = poly.GetStateFlag();
com.esri.core.geometry.Envelope env = new com.esri.core.geometry.Envelope(1000, 2000, 1010, 2010);
env.ToString();
poly.AddEnvelope(env, false);
poly.ToString();
number = poly.GetStateFlag();
NUnit.Framework.Assert.IsTrue(System.Math.Abs(poly.CalculateArea2D() - 100) < 1e-12);
NUnit.Framework.Assert.IsTrue(System.Math.Abs(poly.CalculateLength2D() - 40) < 1e-12);
poly.SetEmpty();
number = poly.GetStateFlag();
poly.AddEnvelope(env, true);
number = poly.GetStateFlag();
NUnit.Framework.Assert.IsTrue(System.Math.Abs(poly.CalculateArea2D() + 100) < 1e-12);
number = poly.GetStateFlag();
}
public static void TestPolygonAreaAndLength()
{
com.esri.core.geometry.Polygon poly;
/* const */
double r = 1.0;
/* const */
double epsilon = 1.0e-14;
/* const */
int nMax = 40;
// If r == 1.0 and nMax == 40 and epsilon == 1.0e-14, it will pass.
// But if r == 1.0 and nMax == 40 and epsilon == 1.0e-15, it will fail.
for (int n = 3; n < nMax; n++)
{
// regular polygon with n vertices and length from center to vertex
// = r
poly = new com.esri.core.geometry.Polygon();
double theta = 0.0;
poly.StartPath(r, 0.0);
for (int k = 1; k <= n; k++)
{
theta -= 2 * System.Math.PI / n;
poly.LineTo(r * System.Math.Cos(theta), r * System.Math.Sin(theta));
}
double sinPiOverN = System.Math.Sin(System.Math.PI / n);
double sinTwoPiOverN = System.Math.Sin(2.0 * System.Math.PI / n);
double analyticalLength = 2.0 * n * r * sinPiOverN;
double analyticalArea = 0.5 * n * r * r * sinTwoPiOverN;
double calculatedLength = poly.CalculateLength2D();
double calculatedArea = poly.CalculateArea2D();
NUnit.Framework.Assert.IsTrue(System.Math.Abs(analyticalLength - calculatedLength) < epsilon);
NUnit.Framework.Assert.IsTrue(System.Math.Abs(analyticalArea - calculatedArea) < epsilon);
}
}
