public static int AngleNum(this Polygon2d polygon2d, double tarAngle = 90)
{
int angleCount = 0;
for (int i = 0; i < polygon2d.VertexCount; i++)
{
if (polygon2d.OpeningAngleDeg(i).EqualPrecision(tarAngle))
{
angleCount += 1;
}
}
return(angleCount);
}
/// <summary>
/// 删除多边形的尖角 删除共线的点
/// </summary>
/// <returns></returns>
public static Polygon2d RemoveSharpCcorners(this Polygon2d polygon2d, double AnglePRECISION = 1.0)
{
List <Vector2d> vector2ds = new List <Vector2d>();
for (int i = 0; i < polygon2d.VertexCount; i++)
{
double openingAngle = polygon2d.OpeningAngleDeg(i);
if (openingAngle >= AnglePRECISION && openingAngle <= 180 - AnglePRECISION)
{
vector2ds.Add(polygon2d[i]);
}
}
return(new Polygon2d(vector2ds));
}
/// <summary>
/// 线圈是否为矩形
/// </summary>
/// <returns></returns>
public static bool IsRectangle(this Polygon2d polygon2d)
{
int count = polygon2d.VertexCount;
if (count != 4)
{
return(false);
}
for (int i = 0; i < polygon2d.VertexCount; i++)
{
if (!polygon2d.OpeningAngleDeg(i).EqualPrecision(90))
{
return(false);
}
}
return(true);
}
/// <summary>
/// 线圈是否为直角梯形
/// </summary>
/// <returns></returns>
public static bool IsTrapezoid_RightAngle(this Polygon2d polygon2d)
{
int count = polygon2d.VertexCount;
if (count != 4)
{
return(false);
}
int calAngleCounr = 0;
for (int i = 0; i < polygon2d.VertexCount; i++)
{
if (polygon2d.OpeningAngleDeg(i).EqualPrecision(90))
{
calAngleCounr += 1;
}
}
if (calAngleCounr != 2)
{
return(false);
}
IEnumerable <Segment2d> segment2ds = polygon2d.SegmentItr();
int segmntCount = segment2ds.Count();
for (int i = 0; i < segmntCount; i++)
{
for (int j = 0; j < segmntCount; j++)
{
if (i <= j)
{
continue;
}
Segment2d segment2d01 = segment2ds.ElementAt(i);
Segment2d segment2d02 = segment2ds.ElementAt(j);
if (segment2d01.Direction.Dot(segment2d02.Direction).EqualPrecision(-1))
{
return(true);
}
}
}
return(false);
}
/// <summary>
/// 线圈是否为三角形
/// </summary>
/// <param name="polygon2d"></param>
/// <returns></returns>
public static bool IsTriangle(this Polygon2d polygon2d)
{
int count = polygon2d.VertexCount;
if (count != 3)
{
return(false);
}
double angle = 0;
for (int i = 0; i < polygon2d.VertexCount; i++)
{
angle += polygon2d.OpeningAngleDeg(i);
}
if (angle.EqualPrecision(180))
{
return(true);
}
return(false);
}