Program Malovani;
// příklad použití externích funkcí ze syst. knihoven Windows

const 
  uroven = 99;
  opakovani = 130;
  penwidth = 50;

function MessageBox(x:short; var s,t:string[20]; y: short) : 
short;
  external 'USER.EXE' name 'MESSAGEBOX';
function TextOut(x,y,z:short; var s:string[1]; v: short) : 
short;
  external 'GDI.EXE' name 'TEXTOUT';
function SetWindowPos(u,v,w,x,y,z,zz:short) : short;
  external 'USER.EXE' name 'SetWindowPos';
function ShowWindow(u,v:short) : short;
  external 'USER.EXE' name 'ShowWindow';

function GetCurrentTime : integer;
  external 'USER.EXE' name 'GETCURRENTTIME';
function GetInputState: short;
  external 'USER.EXE' name 'GETINPUTSTATE';
function GetActiveWindow : short;
  external 'USER.EXE' name 'GETACTIVEWINDOW';
function GetWindowDC(x:short) : short;
  external 'USER.EXE' name 'GETWINDOWDC';
function ReleaseDC(x,y:short) : short;
  external 'USER.EXE' name 'RELEASEDC';
function CreatePen(x, y, z : integer): short;
  external 'GDI.EXE' name 'CREATEPEN';
function DeleteObject(x: short): short;
  external 'GDI.EXE' name 'DELETEOBJECT';
function SelectObject(x, y: short): short;
  external 'GDI.EXE' name 'SELECTOBJECT';
function MoveTo(x,y,z: short): short;
  external 'GDI.EXE' name 'MOVETO';
function LineTo(x,y,z: short): short;
  external 'GDI.EXE' name 'LINETO';

var 
  d_start : date;
  t_start : time;
  hwnd, hdc, hpen, hpenOld : short;
  i, j, is, js, k, l : short;
  seed : integer;
  s : string[20];

function Random(mez : short):short;
const   
  c1 = 13849;
  c2 = 27181;
  c3 = 65536;
var 
  pom : integer;
begin
  seed := (c1 + (c2 * seed)) mod c3;
  pom := Round(seed / (65536 / mez));
  if pom = 0 then pom := 1;
  Random := pom;
end;

function RGB(r,g,b : short): integer;
begin
  RGB := (b*256 + g)*256 + r;
end;

function konec : boolean;
const
  Miliseconds = 3000;

var
  dt : date;
  tm : time;
  limit : boolean;
begin
  dt := Today;
  tm := Now;
  limit := Day(dt) <> Day(d_start);
  if not limit then 
    limit := tm - t_start > Miliseconds;
  if limit 
    then konec := GetInputState <> 0
    else konec := false;
end;

begin
  d_start := Today;
  t_start := Now;
  seed := Seconds(t_start);

  hwnd := GetActiveWindow;
  hDC := GetWindowDC(hwnd);
  hpen := CreatePen(0, Random(penwidth), 
            RGB(Random(255), Random(255), Random(255)));
  hpenOld := SelectObject(hDC, hpen);

  k := 0;
  i := 10;
  j := 10;
  is := Random(uroven);
  js := Random(uroven);

  repeat

    if (i+is>640) or (i+is<0) then
    begin
      SelectObject(hDC, hpenOld);
      DeleteObject(hpen);
      hpen := CreatePen(0, Random(penwidth), 
                 RGB(Random(255), Random(255), Random(255)));
      hpenOld := SelectObject(hDC, hpen);
      if is > 0 
        then is := -Random(uroven)
        else is := Random(uroven);
    end;

    if (j+js>480) or (j+js<0) then
    begin
      SelectObject(hDC, hpenOld);
      DeleteObject(hpen);
      hpen := CreatePen(0, Random(penwidth), 
                RGB(Random(255), Random(255), Random(255)));
      hpenOld := SelectObject(hDC, hpen);
      if js > 0 
        then js := -Random(uroven)
        else js := Random(uroven);
    end;

    MoveTo( hDC, i, j);
    i := i + is;
    j := j + js;
    LineTo( hDC, i, j);

    k := k + 1;
    if (k mod opakovani = 0) and (GetInputState = 0) then
    begin
      TextOut(hDC, Random(600), Random(400),
        "Klikni nebo stiskni klávesu...", 30);
    end;


  until konec;

  SelectObject(hDC, hpenOld);
  DeleteObject(hpen);
  ReleaseDC(hwnd, hDC);

/*  SetWindowPos(hwnd, 1,0,0,0,0, 1 or 2);
  SetWindowPos(hwnd, 0,0,0,0,0, 1 or 2 or 64);*/
  ShowWindow(hwnd, 2);
  ShowWindow(hwnd, 3);
  MessageBox(0, "Konec makra", "Makro", 0 or 64 || 8192);
end.