axiosengine/axios/Common/Decomposition/CDT/Util/PolygonGenerator.cs

98 lines
4.0 KiB
C#

/* Poly2Tri
* Copyright (c) 2009-2010, Poly2Tri Contributors
* http://code.google.com/p/poly2tri/
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Poly2Tri nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
using System;
using Poly2Tri.Triangulation.Polygon;
namespace Poly2Tri.Triangulation.Util
{
public class PolygonGenerator
{
private static readonly Random RNG = new Random();
private static double PI_2 = 2.0*Math.PI;
public static Polygon.Polygon RandomCircleSweep(double scale, int vertexCount)
{
PolygonPoint point;
PolygonPoint[] points;
double radius = scale/4;
points = new PolygonPoint[vertexCount];
for (int i = 0; i < vertexCount; i++)
{
do
{
if (i%250 == 0)
{
radius += scale/2*(0.5 - RNG.NextDouble());
}
else if (i%50 == 0)
{
radius += scale/5*(0.5 - RNG.NextDouble());
}
else
{
radius += 25*scale/vertexCount*(0.5 - RNG.NextDouble());
}
radius = radius > scale/2 ? scale/2 : radius;
radius = radius < scale/10 ? scale/10 : radius;
} while (radius < scale/10 || radius > scale/2);
point = new PolygonPoint(radius*Math.Cos((PI_2*i)/vertexCount),
radius*Math.Sin((PI_2*i)/vertexCount));
points[i] = point;
}
return new Polygon.Polygon(points);
}
public static Polygon.Polygon RandomCircleSweep2(double scale, int vertexCount)
{
PolygonPoint point;
PolygonPoint[] points;
double radius = scale/4;
points = new PolygonPoint[vertexCount];
for (int i = 0; i < vertexCount; i++)
{
do
{
radius += scale/5*(0.5 - RNG.NextDouble());
radius = radius > scale/2 ? scale/2 : radius;
radius = radius < scale/10 ? scale/10 : radius;
} while (radius < scale/10 || radius > scale/2);
point = new PolygonPoint(radius*Math.Cos((PI_2*i)/vertexCount),
radius*Math.Sin((PI_2*i)/vertexCount));
points[i] = point;
}
return new Polygon.Polygon(points);
}
}
}