2 задания по С++Builder2009!

//---------------------------------------------------------------------------
 
#include <vcl.h>
#include <math.h>
#pragma hdrstop
 
#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
int x1, y1, x2, y2, x3, y3, a, d1, d2, r, x0, y0;
float d, r2;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
a=0;
}
//---------------------------------------------------------------------------
 
 
void __fastcall TForm1::FormMouseDown(TObject *Sender, TMouseButton Button,
      TShiftState Shift, int X, int Y)
{
switch (a)
{
case 0:
x1=X;
y1=Y;
a++;
break;
case 1:
x2=X;
y2=Y;
a++;
break;
case 2:
x3=2*x2-x1;
y3=2*y1-y2;
Canvas->MoveTo(x1,y1);
Canvas->LineTo(x2,y2);
Canvas->MoveTo(x2,y2);
Canvas->LineTo(x3,y1);
Canvas->MoveTo(x3,y1);
Canvas->LineTo(x2,y3);
Canvas->MoveTo(x2,y3);
Canvas->LineTo(x1,y1);
a++;
break;
case 3:
d1=x3-x1;
d2=y3-y2;
d=sqrt(((d1*d1)+(d2*d2))*0.25);
r2=(d1*d2)/(4*d) ;
r=ceil(r2);
x0=x2;
y0=y1;
Canvas->Ellipse(x0-r,y0-r,x0+r,y0+r);
a=4;
break;
}
}
//---------------------------------------------------------------------------