Re: LOGO-L> slowdraw

[George Mills <mills@softronix.com>]

A couple comments:

Your idea of moving along the line is nice.

You certainly can remove the "if not :speed = 0" if you like but you
cannot remove the "restore" code. Otherwise if you call slowdraw more
than once your in big trouble. There are other ways to do it as well.

Note there is no reason for an "external" make.
You could of simply done this:

to slowdraw :thespeed
make "speed :thespeed
.
.
.
end

But I thought my solution was more fun (more in the spirit of logo/lisp)
and
eliminates the need for any "globals". My rule of thumb is not to avoid
MAKE
but avoid GLOBALs when possible.

Note also there are other ways to form the definition of the the new
FD/BK such
that you get certain parameters resolved and not others when it's being
defined.
I think some sprinkled SENTENCE's would of worked out better.

to slowdraw :speed
make "redefp "true
; Restore things if already slow
if primitivep "origforward~
   [
   copydef "forward "origforward
   copydef "fd      "origforward
   erase "origforward
   ]
if primitivep "origback~
   [
   copydef "back    "origback
   copydef "bk      "origback
   erase "origback
   ]
; if a delay was specified define new slow draw routines
if not :speed = 0~
   [
   copydef "origforward "forward
   copydef "origback    "back
   erase "fd
   define "fd (list [d] (list "repeat :speed (list "origforward (word ":
"d) "/ :speed "wait 1)))
   erase "bk
   define "bk (list [d] (list "repeat :speed (list "origback    (word ":
"d) "/ :speed "wait 1)))
   copydef "forward "fd
   copydef "back    "bk
   ]
make "redefp "false
end

MHELHEFNY@FRCU.EUN.EG wrote:
> 
> ;Hello George Mills
> ;Here is another form of the slowdraw procedure;which may look like
> ;a real slowdraw.
> ;(p.s. in this version you can't use slowdraw 0; you also
> ;must assigne a value for the speed befor using the
> ;slowdraw procedure).
> ;Regards
> ;Mhelhefny.
> ;--------------------------------
> 
> to slowdraw :speed
> make "redefp "true
>   copydef "origforward "forward
>   copydef "origback    "back
>   erase "fd
>   define "fd [[d][repeat :speed[origforward :d/:speed wait 1]]]
>   erase "bk
>   define "bk [[d][repeat :speed[origback    :d/:speed wait 1]]]
>   copydef "forward "fd
>   copydef "back    "bk
> end
> 
> to demo
> make "speed 60 slowdraw :speed
> cs repeat 3[cstar 50]
> end
> 
> to cstar :size
> fd :size
> lt 120
> fd 2 * :size
> lt 60
> fd 2 * :size
> lt 120
> fd :size
> rt 60
> end
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-- 
===============================================================
George Mills
email: mills@softronix.com
http://www.softronix.com
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