unit MainMenuUnit;
interface
uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.ExtCtrls, Vcl.Imaging.pngimage,
  Vcl.StdCtrls, Vcl.Buttons, Vcl.Imaging.jpeg, Vcl.Imaging.GIFImg, Vcl.ComCtrls;

type
  TMainForm = class(TForm)
    LeftCloudImg: TImage;
    RightCloudImg: TImage;
    TimerOfLeft: TTimer;
    TimerOfRight: TTimer;
    StartButton: TBitBtn;
    RainbowImg: TImage;
    RainImg: TImage;
    Image1: TImage;
    TimerOfRain: TTimer;
    procedure TimerOfLeftTimer(Sender: TObject);
    procedure TimerOfRightTimer(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure StartButtonClick(Sender: TObject);
    procedure TimerOfRainTimer(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  MainForm: TMainForm;

implementation
{$R *.dfm}
var
    Sign: Integer;

procedure TMainForm.StartButtonClick(Sender: TObject);
begin
    TimerOfLeft.Enabled := not TimerOfLeft.Enabled;
    TimerOfRight.Enabled := not TimerOfRight.Enabled;
    TimerOfRain.Enabled := not TimerOfRain.Enabled;
    if TimerOfLeft.Enabled then
        StartButton.Caption := 'Прекратить суету'
    else
        StartButton.Caption := 'Навести суету'
end;

procedure TMainForm.FormCreate(Sender: TObject);
begin
    Sign := 1;
    RightCloudImg.Parent.DoubleBuffered := True;
    LeftCloudImg.Parent.DoubleBuffered := True;
    RainImg.Parent.DoubleBuffered := True;
end;

procedure TMainForm.TimerOfLeftTimer(Sender: TObject);
begin
    LeftCloudImg.Left := LeftCloudImg.Left + 1;
end;

procedure TMainForm.TimerOfRainTimer(Sender: TObject);
const
    EXPANSION = 2;
    CONTRACTION = 4;
    RAIN_TRANSLATION = 15;
begin
    if RainImg.Visible then
    begin
        Sign := -Sign;
        RainImg.Top := RainImg.Top + RAIN_TRANSLATION * sign;
        RainImg.Left :=  RightCloudImg.Left;
        RainImg.Width := RainImg.Width + EXPANSION;
        if RightCloudImg.Left - LeftCloudImg.Left < 0 then
        begin
            RainImg.Left :=   LeftCloudImg.Left;
            RainImg.Width := RainImg.Width - CONTRACTION;
        end;
    end;
end;

procedure TMainForm.TimerOfRightTimer(Sender: TObject);
const
    CLOUD_WIDTH = 345;
var
    IsOverlapped: Boolean;
begin
    RightCloudImg.Left := RightCloudImg.Left - 1;
    RainbowImg.Visible := (RightCloudImg.Left - LeftCloudImg.Left + CLOUD_WIDTH) < 0;
    RainImg.Visible := (RightCloudImg.Left - LeftCloudImg.Left < CLOUD_WIDTH) and
    ((RightCloudImg.Left - LeftCloudImg.Left + CLOUD_WIDTH) > 0);
    if RightCloudImg.Left = 0 then
    begin
        LeftCloudImg.Left := 0;
        RightCloudImg.Left := 764;
    end;
end;

end.