/// <summary>
///
/// </summary>
/// <param name="pn"></param>
/// <returns></returns>
internal SvgPathItem CreateRoundCorner(Vector2 pn)
{
var pc = GetPoint();
var pb = befor.GetPoint();
var a1 = MathF.Atan2(pc.Y - pb.Y, pc.X - pb.X); //傾き
var a2 = MathF.Atan2(pn.Y - pc.Y, pn.X - pc.X); //次の線の傾き
var a = (a1 + a2) / 2;
a = MathF.Abs(a);
if (a > MathF.PI)
{
a -= MathF.PI;
}
float r = 2;
float v = 0;
v = r / MathF.Tan(a); // 半径r円の接点の頂点からの距離
float l1 = CmUtils.Length(pb, pc); // 自分の線の長さ
float l2 = CmUtils.Length(pc, pn); // 次の線の長さ
if (l1 < v || l2 < v)
{
return(null);
}
var citem = new SvgPathItem('C', this);
var x = MathF.Cos(a1) * v;
var y = MathF.Sin(a1) * v;
var p1 = new Vector2(pc.X - x, pc.Y - y);
x = MathF.Cos(a2) * v;
y = MathF.Sin(a2) * v;
var p2 = new Vector2(pc.X + x, pc.Y + y);
var c = r * 0.5522847f; // 半径rの円弧に近似するためのコントロールポイントの長さ
x = MathF.Cos(a1) * c;
y = MathF.Sin(a1) * c;
var c1 = new Vector2(p1.X + x, p1.Y + y);
x = MathF.Cos(a2) * c;
y = MathF.Sin(a2) * c;
var c2 = new Vector2(p2.X - x, p2.Y - y);
var points = new List <Vector2>();
points.Add(c1);
points.Add(c2);
points.Add(p2);
citem.SetPoints(points);
this.points[0] = p1;
CmUtils.DebugWriteLine(string.Format("a1:{0:0.00},a2:{1:0.00},vl:{2:0.00},cl:{3:0.00}", CmUtils.ToAngle(a1), CmUtils.ToAngle(a2), v, c));
return(citem);
}
