turtle graph
lazarus / 39-Graphics

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tr_escape · 2013-09-08 18:32

hello everyone

is there anyone remember turtle graph?
i am looking for graph functions like as turtle graph in lazarus

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Bart · 2013-09-08 22:47

Wasn't that part of TP 3?
I should still have a copy of that somewhere.

Bart

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tr_escape · 2013-09-09 05:03

Yes it was in turbo pascal , actually i was cleaning my bookself and i
saw my old books about pascal. When i saw turtle graph , i sopposed
maybe in pascal already there is.

Is there any library or component about it?

Thanks a lot

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Bart · 2013-09-09 10:16

I haven't seen it around.
Would be nice (nostalgia...) to have something like it, both for
FreePascal (using Graph unit) and for Lazarus...

Bart

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eny · 2013-09-09 17:07

The turtle graphic procedures (actually, 5 functions) where
implemented as assembler routines and included in the com-file during
the 1-pass compilation.
You'd either have to disassemble them or do a bit of trial and error
in a DosBox with the original TP3 compiler.
And indeed would be nice from a nostalgic/retro point of view to got
it working in Lazarus

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circular · 2013-09-09 19:45

I suppose you can do this with Canvas2D of BGRABitmap:
Code: [Select]    procedure rotate(angleRad: single);
    procedure translate(x,y: single);
    procedure strokeStyle(color: TColor); overload;
    procedure beginPath;
    procedure moveTo(x,y: single); overload;
    procedure lineTo(x,y: single); overload;
    procedure stroke;

To advance you can do: beginPath; moveTo(0,0); translate(1,0);
lineTo(0,0); stroke;
To turn: rotate(10*Pi/180)
To change color: strokeStyle(...)

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ToBr · 2013-09-16 20:13

Maybe David Dirkse can help you
See www.davdata.nl

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lainz · 2017-11-28 03:05

Hi, I know this is really old but it shows first in a google search,
so I think it worth to comment here.

In no time thanks to @Circular details on how to implement it I made
this turtle graphics demo:
https://github.com/lainz/turtlegraphics

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  
Bitmap.Fill(BGRAWhite);   reset(Bitmap);  set_color(Bitmap, 0, 0, 255,
255);   // 5 points star  translate(Bitmap, (Bitmap.Width div 2) -
100, (Bitmap.Height div 2) - 50);  for i := 1 to 5 do  begin   
move(Bitmap, 200);    rotate(Bitmap, 144);  end;   reset(Bitmap); 
set_color(Bitmap, 0, 255, 0, 255);   // 9 triangles  translate(Bitmap,
(Bitmap.Width div 2) - 50, (Bitmap.Height div 2) - 120);  for i := 1
to 3 do  begin    move(Bitmap, 200);    for j := 1 to 2 do    begin  
  rotate(Bitmap, 120);      move(Bitmap, 100);    end;    for j := 1
to 2 do    begin      rotate(Bitmap, -120);      move(Bitmap, 100);  
end;    rotate(Bitmap, 120);  end;
Hope I will play more with this and include a proper class, standard
naming of functions and demo with pascal scripting.

I get into this thanks to python "turtle demo" in the python IDLE
shell help menu.