В-сплайновые кривые - C++ Builder - Ответ 9137640

TForm3 *Form3;
//---------------------------------------------------------------------------
__fastcall TForm3::TForm3(TComponent* Owner)
    : TForm(Owner)
{
#define ic Image1->Canvas
}
int count, flag=0;
TPoint point[100];
double tmin = 0., tmax = 200.;
double step = count-1. + count + 1;
 
double N(UINT q, UINT k, double t)
{
  if (q == 1)
  {
    if (t >= tmin + step * k && t <= tmin + step * (k + 1))
      return 1;
    else
      return 0;
  }
  else
    return (t - tmin - step * k) / (tmin + step * (k + q + 1) - tmin - step * k) * N(q-1, k, t) +
           (tmin + step * (k + q) - t) / (tmin + step * (k + q) - tmin - step * (k + 1)) * N(q-1, k+1, t);
}
//---------------------------------------------------------------------------
TPoint R(UINT q, double t)
{
  TPoint b = TPoint(0, 0);
  double temp;
  for (UINT i = 0; i < count; i++)
  {
    temp = N(q, i, t);
    b.x += point[i].x * temp;
    b.y += point[i].y * temp;
  }
  return b;
}
//---------------------------------------------------------------------------
void __fastcall TForm3::Button1Click(TObject *Sender)
{
 
    if (flag) {
    Refresh();
    UINT n = count-1;
    TPoint a;
 
    double step = 0.001;
 
     for(double t = tmin + step; t <= tmax; t += step)
    {
        a = R(n, t);
        if (a.x > 10 && a.y > 10)
          ic->LineTo(a.x, a.y);
     }
     flag=0;
} else count = 0;
flag=1;
}
//---------------------------------------------------------------------------
void __fastcall TForm3::Image1MouseDown(TObject *Sender, TMouseButton Button, TShiftState Shift,
          int X, int Y)
{
ic->Pen->Width=10;
ic->Pen->Color=clBlack;
point[count]= TPoint(X,Y);
ic->MoveTo(X,Y);
ic->LineTo(X,Y);
if (count) {
   ic->Pen->Width=3;
   ic->Pen->Color=clSilver;
   ic->MoveTo(point[count-1].X, point[count-1].Y);
   ic->LineTo(X,Y);
}
count++;
}