Fibonacci Word Fractal
lazarus / 39-Graphics

----------------------------------------------------------------------
Boleeman · 2024-06-07 10:04

A Fibonacci Word Fractal.

When the N value is low you will need to increase the step size,
otherwise the curve is drawn too small to be seen correctly.

Wondered how to make the canvas oversized to be able to see the
fractal at larger recursion levels?

(Possibly a Zoom control, BgraVirtualScreen ?)

As shown in the 2nd attached picture, the fractal curve is only partly
seen. How to see that whole curve?

----------------------------------------------------------------------
Handoko · 2024-06-16 21:08

Quote from: Boleeman on June 07, 2024, 12:04:35 pm(Possibly a Zoom
control, BgraVirtualScreen ?)

Done.

I quickly rewrite your code tested on Linux only, it may contain bugs.

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i unit
Unit1; {$mode objfpc}{$H+} interface uses  Classes, SysUtils, Forms,
Controls, Graphics, Dialogs, ExtCtrls, Spin,  StdCtrls, ComCtrls,
OpenGLContext, GL, Math; type   { TForm1 }   TForm1 = class(TForm)   
cbBackcolor: TColorButton;    cbLinecolor: TColorButton;    Label1:
TLabel;    Label2: TLabel;    Label3: TLabel;    Label4: TLabel;   
Label5: TLabel;    OpenGLControl1: TOpenGLControl;    Panel1: TPanel; 
  seLinewidth: TSpinEdit;    seNvalue: TSpinEdit;    seStepSize:
TSpinEdit;    TrackBar1: TTrackBar;    procedure FormCreate(Sender:
TObject);    procedure ControlChange(Sender: TObject);    procedure
OpenGLControl1Resize(Sender: TObject);  private    glTextureID:
array[0..0] of GLuint; // OpenGL texture    procedure DoDraw;   
procedure DrawWordFractal(n: Integer; g: TCanvas; x, y, dx, dy:
integer);    function GetWordFractal(n: Integer): string;  public  
end; var  Form1: TForm1; implementation {$R *.lfm} { TForm1
} procedure TForm1.FormCreate(Sender: TObject);begin   Panel1.Align  
                  := alLeft;  OpenGLControl1.Align              :=
alClient;  OpenGLControl1.AutoResizeViewport := True;  
seNvalue.MinValue                 := 1;  seNvalue.MaxValue           
    := 30;  seNvalue.Value                    := 20;  
seStepSize.MinValue               := 1;  seStepSize.MaxValue         
    := 20;  seStepSize.Value                  := 3;  
seLinewidth.MinValue              := 1;  seLinewidth.MaxValue        
    := 10;  seLinewidth.Value                 := 2;  
cbLinecolor.ButtonColor           := clBlack;  cbBackcolor.ButtonColor
          := clWhite; end; procedure TForm1.ControlChange(Sender:
TObject);begin  DoDraw;end; procedure
TForm1.OpenGLControl1Resize(Sender: TObject);const  ZNear = 0.1;  ZFar
 = 100;var  X, Y: GLdouble;begin  glViewport(0, 0,
OpenGLControl1.Width, OpenGLControl1.Height); 
glMatrixMode(GL_PROJECTION);  glLoadIdentity;  Y := Tan(40 * Pi / 360)
* ZNear;  X := Y * OpenGLControl1.Width / OpenGLControl1.Height; 
glFrustum(-X, X, -Y, Y, ZNear, ZFar);  glMatrixMode(GL_MODELVIEW); 
glLoadIdentity;  DoDraw;end; procedure TForm1.DoDraw;const 
PictureSize = 1000;var  Bitmap: TBitmap;begin   Bitmap        :=
TBitmap.Create;  Bitmap.Height := PictureSize;  Bitmap.Width  :=
PictureSize;  Bitmap.Clear;  DrawWordFractal(seNvalue.Value,
Bitmap.Canvas, 20, Bitmap.Height - 20, seStepSize.Value, 0);  
OpenGLControl1.MakeCurrent;  glGenTextures(1, glTextureID); 
glBindTexture(GL_TEXTURE_2D, glTextureID[0]); 
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP); 
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP); 
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); 
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); 
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, PictureSize, PictureSize, 0,
GL_RGBA,    GL_UNSIGNED_BYTE, Bitmap.RawImage.Data); 
glBindTexture(GL_TEXTURE_2D, glTextureID[0]);  Bitmap.Free;  
glEnable(GL_TEXTURE_2D);  glClear(GL_COLOR_BUFFER_BIT or
GL_DEPTH_BUFFER_BIT);  glLoadIdentity;  glTranslatef(0, 0,
-TrackBar1.Position/2);  glBegin(GL_QUADS);    glTexCoord2f(0, 1);
glVertex3f(-1, -1, 0);    glTexCoord2f(1, 1); glVertex3f( 1, -1, 0); 
 glTexCoord2f(1, 0); glVertex3f( 1,  1, 0);    glTexCoord2f(0, 0);
glVertex3f(-1,  1, 0);  glEnd;  OpenGLControl1.SwapBuffers; 
glDeleteTextures(1, glTextureID); end; function
TForm1.GetWordFractal(n: Integer): string;var  f1, f2, tmp: string; 
i: Integer;begin  case n of    0: Result := '';    1: Result := '1'; 
else    begin      f1 := '1';      f2 := '0';      for i := n - 2
downto 1 do      begin        tmp := f2;        f2 := f2 + f1;       
f1 := tmp;      end;      Result := f2;    end;  end;end; procedure
TForm1.DrawWordFractal(n: Integer; g: TCanvas; x, y, dx, dy:
integer);var  i, tx: Integer;  wordFractal: string;begin  wordFractal
:= GetWordFractal(n);  with g do  begin    Brush.Color :=
cbBackcolor.ButtonColor;    FillRect(ClipRect);    Pen.Color :=
cbLinecolor.ButtonColor;    Pen.Width := seLinewidth.Value;   
MoveTo(x, y);  end;  for i := 1 to wordFractal.Length do  begin   
g.LineTo(x + dx, y + dy);    Inc(x, dx);    Inc(y, dy);    if
wordFractal[i] = '0' then    begin      tx := dx;      if Odd(i) then 
    begin        dx := dy;        dy := -tx;      end      else     
begin        dx := -dy;        dy := tx;      end;    end; 
end;end; end.
Because I used TOpenGLContext, you need to enable LazOpenGLContext
package in your Lazarus by doing:
Lazarus main menu > Package > Install/Uninstall Packages > right
panel, select: LazOpenGLContext 0.0.1 > Install selection > Save and
rebuild IDE

Make sure your computer has VGA driver installed properly. For Linux
users, you need to have libgl1-mesa-dev installed.

In the uses clause I added OpenGLContext, GL, Math (see line #9).  In
Form.OnCreate event I added some lines, see line #53..55. For the
OpenGL control to be able to do proportional resizing, I added the
code for OpenGLControl1Resize event, see line #79.

If you want to change the picture size, see line #99. To change the
zoom increment value, see line #125.

All the repaints now are handled by DoDraw, see line #97. It is done
by doing the fractal drawing to a bitmap and then draw to bitmap's
texture in the OpenGL control.

----------------------------------------------------------------------
Boleeman · 2024-06-17 06:15

Thanks Handoko for your Linux version.

I wanted to do an install of Linux.

Wondered what type of Linux and version I should install that works
reliably with Lazarus?

----------------------------------------------------------------------
TRon · 2024-06-17 06:50

Quote from: Boleeman on June 17, 2024, 08:15:18 amWondered what type
of Linux and version I should install that works reliably with
Lazarus?
Go with what looks like you are most comfortable with.

If you come from f.e. windows then there are special Linux distro's
tailored for windows users (these attempt to try and make you feel at
home).

I would personally advise to go with something debian based and for
your dear life please stay away from wayland.

And whatever you do do not install Lazarus from your distro's package
manager: do it manually or use fpcupdeluxe.

BTW: be advised that such question could potentially end up as a topic
of its own so perhaps worth considering spending a separate thread for
it.

----------------------------------------------------------------------
cdbc · 2024-06-17 07:08

Hi
QuoteWondered what type of Linux and version I should install that
works reliably with Lazarus?<Spoiler Alert>
You should try and have a look at PCLinuxOS:
https://www.pclinuxos.com/?page_id=180 It's an easy transit, when you
come from windows. Even though it's a 'rolling release', it's a bit
conservative e.g.: the distro will wait with Wayland, till it's
matured a bit/lot and we've even got a Debian flavour, if you so wish.
In the repo, we've got the latest release versions of software and
e.g.: I'm running fpc trunk & laz 3.0, installed from "FpcUpDeluxe",
in paralel 
It's definately worth a try.
<Spoiler End>
Regards Benny

----------------------------------------------------------------------
TRon · 2024-06-17 07:16

I forgot to mention something that Boleeman might be interested in and
it is named ventoy which, after initial setup, allows you to copy-
paste iso's to a flash-drive and which you can then pop into a USB
port, boot and select which ISO you wish to run. Most Linux
distribution provide a live mode CD/DVD iso so that you can test-drive
a distribution.

----------------------------------------------------------------------
Boleeman · 2024-06-17 07:22

Thanks for the advice guys.

Going to have a 2 week (teacher) break coming up soon so will start
the install process then.