Scratch

Fyffer wrote:

Without having to manually change ALL the x-y coordinates that I entered, is there any way to, say, globally add or subtract from every x-y position entry I've created?

I'm not sure if it's possible to do in any other way other than manually editing it, but next time you do something like that, use a variable for the starting position coordinates:

[blocks]<go to x   <{ starting position x }> )y   <{ starting position y }>[/blocks]

Fyffer wrote:

Also, I noticed that with only 5 sprites, and rather simple motion, much of my prescribed motion is supposed to be in sync, i.e. the sprites follow similar paths in parallel, I find the final product to be jumpy - they don't all move at precisely the same time, which will eventually be in sync with music.  When I get up to the 30 I need, I can see it's going to be a mess.  Does it have anything to do with the complexity of the sprite itself?  Or is it just a global issue with the software?

Scratch is quite slow in the default speed mode, so no, it's not a problem with your sprites. You can activate the Turbo Speed mode by going to Edit/Set single stepping/Turbo Speed. However, that feature is not available onine, so JSO's suggestion would be a better choice (that's how I synchronize my MIDI projects).

If you're looking for more advanced ways of synchronizing your MIDI project (assuming that it's MIDI), you might want to check out Jens' stuff: http://scratch.mit.edu/users/jens He has been known for creating synchronized MIDI projects especially adapted for the online player. (although, I'm not quite sure how they work, since I'm not a programming expert) 

First of, this is not Scratch API. This is Scratch IDE. With huge accent on I(ntegrated). You can't edit proper Scratch scripts outside it. That's why there is a spin-off with big chance of success, called M3OW (or Emerald).

There's a specification on .sb file somewhere.

Syncing is a problem for projects with many sprites and scripts. Broadcasts are quick enough to fix it in a way.

To modify all the coords, use global-x and global-y variables and then formulae to convert them to individual sprite coords.

If you came here for an advanced things to make a ballet on screen, I recommend you to use Flash - easier with lots of sprites. If you're still here, though, and want to upload the project to the site, get ready for pain, because it's painstaking.

Also, online player is bad at timing and rendering.

You can possibly edit the scripts programmatically using macros. Scratch provides no native support for them, but there are general system ones.

Jens' Chirp has an XML script export feature...

As far as changing all of the sprites at the same time, I would do this:
1. Make an X and Y variable.
2. Make a broadcast script that runs as follows:
<when I receive[ MoveSprites ]>
<change x by( X )>
<change y by( Y )>
<stop script>
Now, just place above script in all 5 sprites.

If you need to move them, just set X and Y to the values that the sprites
should move (can also be negative), and run this:
<broadcast[ MoveSprites ]>

If you plan to do this in a loop, it is best to use
<repeat( n )>
|<broadcast[ MoveSprites ]and wait c>
<end>

Hope this helps!