/// <summary>
///
/// </summary>
/// <param name="mat"></param>
public override void TransformBy(Matrix2D mat)
{
var vec1 = GetPointAtParam((StartParam + EndParam) / 2) - Center;
Center *= mat;
var vec = Vector2D.XAxis * mat;
Radius *= vec.Length;
if (!Closed)
{
var vec0 = new Vector2D(Radius, StartAngle) * mat;
vec1 *= mat;
var vec2 = new Vector2D(Radius, EndAngle) * mat;
StartAngle = vec0.Angle;
EndAngle = vec2.Angle;
IsClockWise = Vector2D.IsClockWise(vec0, vec1, vec2);
}
}
public CircleArc2D(Point2D pt1, Point2D pt2, Point2D pt3, bool isWholeCircle)
{
if (isWholeCircle)
{
var xy1 = Math.Pow(pt1.X, 2) + Math.Pow(pt1.Y, 2);
var xy2 = xy1 - Math.Pow(pt3.X, 2) - Math.Pow(pt3.Y, 2);
var xy3 = xy1 - Math.Pow(pt2.X, 2) - Math.Pow(pt2.Y, 2);
xy1 = (pt1.X - pt2.X) * (pt1.Y - pt3.Y) - (pt1.X - pt3.X) * (pt1.Y - pt2.Y);
if (GeoUtils.Equals(xy1, 0))
{
throw new Exception("无法创建圆!");
}
Center =
new Point2D(
(xy3 * (pt1.Y - pt3.Y) - xy2 * (pt1.Y - pt2.Y)) / (2 * xy1),
(xy2 * (pt1.X - pt2.X) - xy3 * (pt1.X - pt3.X)) / (2 * xy1));
Radius = (pt1 - Center).Length;
if (GeoUtils.Equals(Radius, 0))
{
throw new Exception("半径为零!");
}
StartAngle = Angle.Zero;
EndAngle = Angle.Degree360;
}
else
{
CircleArc2D cir = new CircleArc2D(pt1, pt2, pt3, true);
Center = cir.Center;
Radius = cir.Radius;
IsClockWise =
Vector2D.IsClockWise(
pt1 - cir.Center,
pt2 - cir.Center,
pt3 - cir.Center);
}
}
/// <summary>
///
/// </summary>
/// <param name="mat"></param>
public override void TransformBy(Matrix2D mat)
{
var pt0 = GetPointAtParam(StartParam);
var pt1 = GetPointAtParam((StartParam + EndParam) / 2);
var pt2 = GetPointAtParam(EndParam);
pt0 *= mat;
pt1 *= mat;
pt2 *= mat;
var vec = MinorAxis * mat;
Minor = vec.Length;
vec = MajorAxis * mat;
Major = vec.Length;
Center *= mat;
Rotation = vec.Angle;
var vec0 = pt0 - Center;
var vec2 = pt2 - Center;
StartAngle = vec0.Angle - Rotation;
EndAngle = vec2.Angle - Rotation;
IsClockWise = Vector2D.IsClockWise(vec0, pt1 - Center, vec2);
}
