Условное перемещение параллелограмма

//---------------------------------------------------------------------------
 
#include <vcl.h>
#include <iostream>
#pragma hdrstop
 
#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
int origin_x=0, origin_y=0, i=0;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::Button1Click(TObject *Sender)
{
i++;
Canvas->FillRect(Rect(0, 0, Form1->ClientWidth, Form1->ClientHeight));
TPoint points[4];
 
points[0] = Point(50+origin_x, 50+origin_y);
points[1] = Point(150+origin_x, 50+origin_y);
points[2] = Point(120+origin_x, 100+origin_y);
points[3] = Point(20+origin_x, 100+origin_y);
Canvas->Polygon(points, 3);
 
if(i=3){
origin_y++;}
 
else if(i=2){
origin_x++;}
 
else if(i=1){
origin_y++;
origin_x++;}
Canvas->Ellipse(37,50,135,100);
}
//---------------------------------------------------------------------------