Scratch

About Gobo's hairstyle:  If you listen carefully to the "full movie" project at http://byob.berkeley.edu, while looking at byob-Gobo, you'll get a clue. 

I totally agree about the splitting thing. I personally want us all to be able to post our projects to the same website. That is my major concern. One Scratch4All !

markyparky56 wrote:

I can't import any of my sprites into BYOB 2.99! Any idea why?

Have you downloaded 2.99.003?  There was a bug about importing sprites that should be fixed now.

markyparky56 wrote:

Is this a glitch
http://img249.imageshack.us/img249/2199/glitchposs.png

It's a known limitation, let's put it that way.     The AS TEXT block is more a Scratch-1.4-compatibility kludge than a carefully planned feature; the block called LIST in Scratch is translated into this block when a Scratch project is loaded into BYOB.  We have recycled the name LIST for the reporter that constructs a new list.  So AS TEXT works well only for Scratch 1.4 lists, in which the elements can only be text, not sublists.  (And even for those, if we were designing an AS TEXT feature it would put spaces between the items!  But we didn't want to break Scratch projects that depend on the current behavior.)

bharvey wrote:

Kingdaro wrote:

Is there any way you can run an entire list of scripts all at once?

Or better yet, add 4 to all the values in a list all at once? The atomic feature is slow.

There isn't any magic in computers; no matter how you program it, unless you have a superscalar processor that does lots of similar arithmetic operations in parallel, it's going to take time proportional to the length of the list to do anything to every item.

But in terms of programming convenience, in tools.sb you'll find MAP.  Just say

   MAP   [< > + <4>] OVER <my-list>

... but when you're dragging the + block onto the MAP block, after you see the white halo, before you let go of the mouse button, move in a little closer, until the white halo goes away and instead you see a grey border around the + block.  /Then/ let go.

Alternative if you don't like that user interface:

  MAP [THE [< > + <4>] BLOCK] OVER <my-list>

THE BLOCK is down at the bottom of the Operators menu.  The grey-border thing is a shortcut for THE BLOCK.  This will all be explained in tutorial #2, which I'm supposed to be writing right now instead of answering forum messages.     (But this is fun!)

Kingdaro wrote:

Also, sometimes the custom blocks don't work in presentation mode.

Okay, this makes three times today, I think, that I've had to respond the same way to a bug report, so don't take it personally when I start shouting.  HEY, GANG, WE REALLY APPRECIATE BUG REPORTS, BUT IT'S VERY HARD TO EVALUATE AND REPRODUCE A BUG IF THE REPORT SAYS "SOMETIMES" INSTEAD OF GIVING DETAILS!

There, now I feel better.     So, what does your custom block do, and how does it fail -- error message, wrong value computed, right value displayed at the wrong scale, sprite does/doesn't go offscreen...  etc.  Thanks!
A screenshot might be best of all if it's hard to explain in words just what happens.

I forgot about the map block. Thanks. 

Also, here are the custom blocks that don't work in presentation:






If you haven't figured it out, I'm making a DDR simulator. :3
You know what, that map block would do the same thing. -.-

My point is that in Lua, when you do a for loop, it does everything literally instantly in the given parameters. "for i=1, 10000 do", even that would happen instantly.

Last edited by Kingdaro (2010-04-29 15:38:33)

bharvey wrote:

As of just now, the BYOB.image on http://byob.berkeley.edu is 2.99.003, fixing most of the bugs reported here in the past week.  We haven't updated the complete packages; just download the image and replace the one in the package you already have.  Thanks again to everyone who's been testing BYOB!

(If you're wondering, 001 and 002 weren't posted because we weren't sure they really worked.) 

Yay!

bharvey wrote:

ElectricSparx wrote:

Umm, Brain,

  People have been misspelling my name that way since I joined the Cub Scouts 52 years ago and that's what they put on my membership card.  It was a refreshing change when I first went to Australia and met someone who /pronounced/ my name "Brawn"! 

ElectricSparx wrote:

your custom made blocks don't work if you use them in the block editor.

Uh, they do for me, so you'll have to be more specific.  What did you try, exactly, and what happened?  Thanks!

I used the "repeat while" block and it gave me an error whenever I moused over the block.

Jens, whyy does it show you are not part of the SCratch Team?

Does anybody know why the 'the script. Input names' block is so messed up? I mean, I'm calling it and getting scripts with input names I have deleted in the past! I am trying to do a bit of OOP but I can't get anywhere when my zero-argument methods are demanding two arguments!
(bharvey, any suggestions?)

nXIII wrote:

Does anybody know why the 'the script. Input names' block is so messed up? I mean, I'm calling it and getting scripts with input names I have deleted in the past! I am trying to do a bit of OOP but I can't get anywhere when my zero-argument methods are demanding two arguments!
(bharvey, any suggestions?)

b-b-b-BUMP!

shadow_7283 wrote:

I've got a guess as to why Gobo has been changed. The antanae look kinda like a one. I'm not going to say anything further in case I am right...

Why not, I am desperate to know and you guys are acting like it's a big secret.

JUST TELL ME I REALLY WANT TO KNOW WHY ARE YOU BEING SO SECRETIVE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Lucario621 wrote:

The (unofficial) BYOB 3 Discussion Thread!

I think you might as well change that to "official"! 

Kingdaro wrote:

here are the custom blocks that don't work in presentation:

I'm going to leave this part for Jens.

Kingdaro wrote:

My point is that in Lua, when you do a for loop, it does everything literally instantly in the given parameters. "for i=1, 10000 do", even that would happen instantly.

I had to look up Lua.  Looks like an interesting language, and, like BYOB3, Scheme-influenced.     It may be that there's a blindingly fast Lua compiler that can iterate 10K times in the blink of an eye, but if it's running on a conventional computer (without 10K processors working at once), that blink is still 10K times as long as the blink for one iteration.

The speed problem in BYOB, as I understand it from Jens, has to do with the tight interaction between expression evaluation and managing the display.  One design principle in Scratch that we've moved away from (but that still survives in BYOB's implementation, which is mostly still Scratch) is that everything in the program should be visible onstage; this is why variable and list watchers default on.  So it made sense  in the context of Scratch to integrate computation and display, bnt if we ever rewrite it from (sorry) scratch, the two parts of the program will be separate and computation that /isn't/ visible will be much, much faster.

Jens?  You want to weigh in on this one?