program MinApp;
uses OWindows, wintypes, winprocs, strings;

type Circle = record
   top: double;
   left: double;
   r:integer;
   g:integer;
   b:integer;
end;

type
TMyApplication = object(TApplication)
   procedure InitMainWindow; virtual;
end;

  PGraphWindow = ^TGraphWindow;
  TGraphWindow = object(TWindow)
    circles: array[1..1000] of Circle;
    i: integer;
    k: integer;
    n: bool;
    procedure Paint(PaintDC: HDC; var PaintInfo: TPaintStruct); virtual;
    procedure WMLButtonDown(var Msg: TMessage); virtual wm_First + wm_LButtonDown;
    procedure Render(TheDC: HDC);
    constructor Init(AParent: PWindowsObject; ATitle:PChar);
end;


constructor TGraphWindow.Init;
 begin
  inherited Init(AParent, ATitle);
  i := 0;
  k := 0;
  n := false;
 end;


procedure TMyApplication.InitMainWindow;
begin
   MainWindow := New(PGraphWindow, Init(nil,'Graph'));
end;


procedure TGraphWindow.WMLButtonDown;
 var
   NewBrush, OldBrush: HBrush;
   TheDC: HDC;
   MyRect: TRect;
 begin
   n := true;
   TheDC := GetDC(HWindow);
   GetClientRect(HWindow, MyRect);

   if (Msg.LParamLo < MyRect.right / 2 and Msg.LParamHi < MyRect.bottom / 2) then begin
    NewBrush:=CreateSolidBrush(RGB(0,0,255));
    OldBrush:=SelectObject(TheDC, NewBrush);
	k := k + 1;
	Ellipse(TheDC, Msg.LParamLo-15, Msg.LParamHi-15, Msg.LParamLo+15, Msg.LParamHi+15);
	circles[k].top := Msg.LParamHi/MyRect.bottom;
	circles[k].left := Msg.LParamLo/MyRect.right;
    circles[k].r := 0;
    circles[k].g := 0;
    circles[k].b := 255;
   end

   if (Msg.LParamLo < MyRect.right / 2 and Msg.LParamHi > MyRect.bottom / 2) then begin
    NewBrush:=CreateSolidBrush(RGB(255,0,0));
    OldBrush:=SelectObject(TheDC, NewBrush);
	k := k + 1;
	Ellipse(TheDC, Msg.LParamLo-15, Msg.LParamHi-15, Msg.LParamLo+15, Msg.LParamHi+15);
	circles[k].top := Msg.LParamHi/MyRect.bottom;
	circles[k].left := Msg.LParamLo/MyRect.right;
    circles[k].r := 255;
    circles[k].g := 0;
    circles[k].b := 0;
   end

   if (Msg.LParamLo > MyRect.right / 2 and Msg.LParamHi < MyRect.bottom / 2) then begin
    NewBrush:=CreateSolidBrush(RGB(0,255,0));
    OldBrush:=SelectObject(TheDC, NewBrush);
	k := k + 1;
	Ellipse(TheDC, Msg.LParamLo-15, Msg.LParamHi-15, Msg.LParamLo+15, Msg.LParamHi+15);
	circles[k].top := Msg.LParamHi/MyRect.bottom;
	circles[k].left := Msg.LParamLo/MyRect.right;
    circles[k].r := 0;
    circles[k].g := 255;
    circles[k].b := 0;
   end

   if (Msg.LParamLo > MyRect.right / 2 and Msg.LParamHi > MyRect.bottom / 2) then begin
    NewBrush:=CreateSolidBrush(RGB(255,255,255));
    OldBrush:=SelectObject(TheDC, NewBrush);
	k := k + 1;
	Ellipse(TheDC, Msg.LParamLo-15, Msg.LParamHi-15, Msg.LParamLo+15, Msg.LParamHi+15);
	circles[k].top := Msg.LParamHi/MyRect.bottom;
	circles[k].left := Msg.LParamLo/MyRect.right;
    circles[k].r := 255;
    circles[k].g := 255;
    circles[k].b := 255;
   end

   NewBrush:=SelectObject(TheDC, OldBrush);
   DeleteObject(NewBrush);
   ReleaseDC(HWindow, TheDC);
 end;

procedure TGraphWindow.Render;
  var l: integer;
  NewBrush, OldBrush: HBrush;
  MyRect:TRect;
begin
  TheDC := GetDC(HWindow);
  GetClientRect(HWindow, MyRect);

  for l := 1 to k do begin
    NewBrush:=CreateSolidBrush(RGB(circles[l].r, circles[l].g, circles[l].b));
    OldBrush:=SelectObject(TheDC, NewBrush);
    Ellipse(TheDC, round(MyRect.right*circles[l].left - 15), round(MyRect.bottom*circles[l].top-15),
      round(MyRect.right*circles[l].left + 15), round(MyRect.bottom*circles[l].top+15));
  end;
end;

procedure TGraphWindow.Paint;
var
  MyRect:TRect;
begin
  GetClientRect(HWindow, MyRect);
  MoveTo(PaintDC, MyRect.left, MyRect.top);
  LineTo(PaintDC, MyRect.right, MyRect.bottom);

  if (n = true) then
    Render(PaintDC);

end;

var
   MyApp: TMyApplication;
begin
   MyApp.Init('TestApp');
   MyApp.Run;
   MyApp.Done;


end.