unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls;

type
  TForm1 = class(TForm)
    Image1: TImage;
    Button1: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  imhgt,imwid,frame:Integer;
  bm1,bm2:tBitmap;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
 imhgt:=Image1.Height;
 imwid:=Image1.Width;

 bm1:=tBitmap.Create;
 bm2:=tBitmap.Create;
 bm1.Width:=imwid;
 bm2.Width:=imwid;
 bm1.Height:=imhgt;
 bm2.Height:=imhgt;


end;

procedure TForm1.Button1Click(Sender: TObject);
var
 x,y,scale,angle,sina,cosa:real;
 i,j,k,midx,midy,xdelta,ydelta:integer;
 xblock,yblock,blockwid,blockhgt,xblockx,yblocky,xblockxmid,yblockymid,xblocks,yblocks:integer;
 xbase,ybase,xfrom,yfrom,xto,yto:integer;
 color1,color2:tColor;
begin
 bm2.Assign(bm1);

 midy:=imhgt div 2;
 midx:=imwid div 2;
 scale:=0.89;
 angle:=0.08;
 sina:=sin(angle)*scale;
 cosa:=cos(angle)*scale;
 blockhgt:=8;
 blockwid:=2;
 yblocks:=imhgt div blockhgt;
 xblocks:=imwid div blockwid;

//add chaos in the center
 if (frame mod 6)=0
 then
 for i:=-2 to 1 do
  for j:=-2 to 0 do
  begin
   color1:=random(2)shl 23+random(2)shl 15+random(2)shl 7;
   color2:=0;
   if(random(8)=0) then color2:=color1;
   bm2.Canvas.Pixels[midx+j*2,midy+i*2]:=color1;
   bm2.Canvas.Pixels[midx+j*2,midy+i*2+1]:=color2;
   bm2.Canvas.Pixels[midx+j*2+1,midy+i*2]:=color2;
   bm2.Canvas.Pixels[midx+j*2+1,midy+i*2+1]:=color1;
  end;
 inc(frame);

 ydelta:=random(2);
 xdelta:=random(2);

//rotate
 for xblock:=0 to xblocks-1 do
   //pop de for this column, set page for current output layer in #c000
  for yblock:=0 to yblocks-1 do //in vertical lines
   begin
    //pop hl (two pages of input screen are already set in #0000..#7fff)
    yblocky:=yblock*blockhgt;
    xblockx:=xblock*blockwid;
    yblockymid:=yblocky+(blockhgt div 2)-midy;
    xblockxmid:=xblockx+(blockwid div 2)-midx;
    ybase:=trunc(yblockymid*cosa+xblockxmid*sina)-(blockhgt div 2)+midy;
    xbase:=trunc(xblockxmid*cosa-yblockymid*sina)-(blockwid div 2)+midx;
    ybase:=((ybase+ydelta) or 1) - 1{(yblocky and 1)};
    xbase:=((xbase+xdelta) or 1) - 1{(xblockx and 1)};
    for i:=0 to blockhgt-1 do
     for j:=0 to blockwid-1 do
     begin
     //dup blockhgt/2
     //ld a,(hl)
     //ld (de),a
     //add hl,bc
     //exd
     //add hl,bc
     //ld a,(de)
     //ld (hl),a
     //add hl,bc
     //exd
     //add hl,bc
     //edup
     //org $-1
            //or you can use ld a,(nn):ld d/e,a:[push de] instead
      yfrom:=ybase+i;
      xfrom:=xbase+j;
      yto:=yblocky+i;
      xto:=xblockx+j;
      bm1.Canvas.Pixels[xto,yto]:=bm2.Canvas.Pixels[xfrom,yfrom];
     end;
   end;

 Image1.Picture.Assign(bm1);
end;

end.