Перерисовка линии

TForm1 *Form1;
Bez B;
int cnt=0;
int cn=0;
 
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::FormMouseDown(TObject *Sender, TMouseButton Button,
      TShiftState Shift, int X, int Y)
{
cnt++;
int n;
n=cnt-1;
//B.drow(X,Y);
if(Shift.Contains(ssMiddle))
  {
  B.drow(X,Y);
   B.linep(X,Y);
 
  }
if(Shift.Contains(ssRight))
  {
  B.drow(X,Y);
  B.linek(X,Y);
  B.roz(X,Y,n);
  }

class Bez{
vector <int> mx;
vector <int> my;
public:
 
void drow(int x,int y);
void linep(int x,int y);
void linek(int x,int y);
void roz(int x,int y,int n);
int fact(int n);
public:
Bez();
~Bez();
};

Bez::Bez()
{};
Bez::~Bez()
{};
 
int Bez::fact(int n){
 if (n==0)
return 1;
else
return n*fact(n-1);
}
 
void Bez::drow(int x,int y){
mx.push_back(x);
my.push_back(y);
Form1->Canvas->Pen->Color=clBlack;
Form1->Canvas->Pen->Width=5;
int r=3;
Form1->Canvas->Ellipse(x+r,y+r,x-r,y-r);
Form1->Canvas->Pen->Width=4;
Form1->Canvas->Pen->Color=clBlue;
}
 
void Bez::linep(int x,int y){
Form1->Canvas->MoveTo(x,y);
}
 
void Bez::linek(int x,int y){
Form1->Canvas->LineTo(x,y);
}
 
void Bez::roz(int x,int y,int n){
double t;
double xt=mx[0];
double yt=my[0];
Form1->Canvas->MoveTo(mx[0],my[0]);
for  (t=0.0001;t<1.0;t+=0.0001)
{
xt = 0;
yt = 0;
for (int i=0;i<mx.size();i++)
{
xt+= double(mx[i])*(double(fact(n))/double(fact(i)*fact(n-i)))*pow(t,double(i))*pow(1-t,double(n-i));
yt+= double(my[i])*(double(fact(n))/double(fact(i)*fact(n-i)))*pow(t,double(i))*pow(1-t,double(n-i));
 
}
Form1->Canvas->Pen->Width=1;
Form1->Canvas->Pen->Color=clRed;
 Form1->Canvas->LineTo(int(xt),int(yt));
 
}
 
    }