//
//ptを通る直交する直線
// A*A' = -1
//
public FN1D GetNormFn(PointF pt)
{
if (this.A == 0.0)
{
//当該直線は水平→垂直の直線を作成
FN1D fn = new FN1D(double.NaN, double.NaN, pt.X);
//fn.A = double.NaN;
//fn.B = double.NaN;
//fn.C = pt.X;
return(fn);
}
else if (double.IsNaN(this.A))
{
//当該直線は垂直→水平の直線を作成
FN1D fn = new FN1D(0, pt.Y, double.NaN);
//fn.A = 0;
//fn.B = pt.Y;
//fn.C = double.NaN;
return(fn);
}
else
{
// double A = this.A * (-1);
double A = (-1) / this.A;
double B = pt.Y - A * pt.X;
return(new FN1D(A, B));
}
}
//---
// Y = A1*X + B1
// と
// Y = A2*X + B2
// 交点を求める
// A1*X + B1 = A2*X + B2
// A1*X - A2*X = B2 - B1
// X(A1-A2) = B2 - B1
// X = (B2 - B1) / (A1 - A2)
public PointF GetCrossPt(FN1D fn)
{
PointF pt = new PointF();
if (this.A == fn.A)
{
pt.X = pt.Y = float.NaN;
}
else if (this.A == fn.A)
{
//両直線は平行
if (double.IsNaN(this.A))
{
G.mlog("here");
this.A = this.A;
}
pt.X = pt.Y = float.NaN;
}
else if (double.IsNaN(this.A))
{
//当該直線は垂直
if (double.IsNaN(fn.A))
{
//対象直線は垂直
pt.X = pt.Y = float.NaN;
}
else if (fn.A == 0.0)
{
//対象直線は水平
pt.X = (float)this.C;
pt.Y = (float)fn.B;
}
else
{
pt.X = (float)this.C;
pt.Y = (float)(fn.A * pt.X + fn.B);
}
}
else if (this.A == 0.0)
{
//当該直線は水平
if (double.IsNaN(fn.A))
{
//対象直線は垂直
pt.X = (float)fn.C;
pt.Y = (float)this.B;
}
else if (fn.A == 0.0)
{
//対象直線は水平
pt.X = pt.Y = float.NaN;
}
else
{
pt.Y = (float)this.B;
pt.X = (float)((pt.Y - fn.B) / fn.A);
}
}
else
{
pt.X = (float)((fn.B - this.B) / (this.A - fn.A));
pt.Y = (float)(this.A * pt.X + this.B);
}
return(pt);
}