Yertle the Turtle

[Jim Hurley]

I had been promoting Turtle Graphics in RR/LC for many years.

Here are 4 implementation of Turtle Graphics in LC: http://jamesphurley.com/Revolution.html <http://jamesphurley.com/Revolution.html>

Jim


> 
> Message: 19
> Date: Mon, 30 Jan 2017 22:20:10 +0200
> From: Richmond Mathewson <richmondmathewson at gmail.com>
> To: "u >> How to use LiveCode" <use-livecode at lists.runrev.com>
> Subject: Yertle the Turtle
> Message-ID: <aefb580f-87f2-cd2f-f22f-01e1dd90b9fe at gmail.com>
> Content-Type: text/plain; charset=utf-8; format=flowed
> 
> Having imported an SVG image of a tortoise into a stack . . .
> 
> Being a fan of Seymour Papert . . .
> 
> I thought I'd try and implement turtle graphics in Livecode.
> 
> But came up against something awkward . . .
> 
> [As a caveat, I should like to point out I don't know how the following 
> is implemented
> in any other languages either]
> 
> 1. Rotating my turtle widget is easy.
> 
> 2. But telling the turtle to move forwards or backwards is not easy at all:
> 
> In LOGO one can tell the turtle to turn left by, say, 30 degrees, and 
> then move forward 20 units.
> 
> But in LiveCode, as far as I know, one can either move an object by 
> setting 2 coordinates,
> or by 'set the loc'.
> 
> 2.1. Now if I want my turtle, rotated at 30 degrees to move forward by 
> 20 units I will have to mess
> around with SINE and COSINE and probably not end up with the turtle 
> moving exactly 20 units at 30
> degrees from the vertical.
> 
> 2.2. I wonder how my turtle will be seen to draw a pen line from the two 
> ends of the "line".
> 
> Richmond.
>