program SetPixelApp;

uses
  KolibriOS;

var
  WndLeft, WndTop, WndWidth, WndHeight: Integer;
  X, Y: Integer;

begin
  with GetScreenSize do
  begin
    WndWidth := 180;
    WndHeight := 180;
    WndLeft := (Width - WndWidth) div 2;
    WndTop := (Height - WndHeight) div 2;
  end;

  while True do
    case WaitEvent of
      REDRAW_EVENT:
        begin
          BeginDraw;

          DrawWindow(WndLeft, WndTop, WndWidth, WndHeight, 'Set Pixel', $00FFFFFF,
            WS_SKINNED_FIXED + WS_CLIENT_COORDS + WS_CAPTION, CAPTION_MOVABLE);

          for Y := 0 to 50 do
            for X := 0 to 50 do
              if ((X mod 2) = 0) or ((Y mod 2) = 0) then
                SetPixel(X, Y, $00FF0000);

          for Y := 50 to 100 do
            for X := 50 to 100 do
              if ((X mod 3) = 0) or ((Y mod 3) = 0) then
                SetPixel(X, Y, $00007F00);

          for Y := 100 to 150 do
            for X := 100 to 150 do
              if ((X mod 4) = 0) or ((Y mod 4) = 0) then
                SetPixel(X, Y, $000000FF);

          EndDraw;
        end;
      KEY_EVENT:
        GetKey;
      BUTTON_EVENT:
        if GetButton.ID = 1 then
          Break;
    end;
end.