Sparrow Forum

1. 

   marwic
   Member

   Hi there!

   Just starting out with Sparrow It looks great so far!

   I'm trying to animate a quad up and down on the screen by chaining two tweens. One tween that moves the quad down 100 px in 2 secs and one that moves it back in 2 secs (as in http://www.sparrow-framework.org/2010/10/tweens-jugglers-unleashed/).

   It works, but when the second tween is completed and we're back at the starting position I would like the animation to start again, so it runs in a loop. Preferably by reusing the tweens.

   I tried [juggler advanceTime -4], thinking that it might work, but no.

   Any ideas (except from recreating the tweens again)?

   /Thanks!

   Posted 1 year ago #
2. 

   Dan
   Member

   Hi,

   You need to set each tween to have the other tween as the completion of the other - I explained that really badly!

   Have a look at the second post in this thread and the code there should make more sense than my waffle: http://forum.sparrow-framework.org/topic/custom-tween-blink-flicker-spin

   Posted 1 year ago #
3. 

   marwic
   Member

   Dan, thanks.

   Yes that might do it. Letting tweens call each other when they are done. Seems a bit of a hack though.

   As it is the juggler who controls the tweens, I think it would be nice if it was possible to tell the juggler to restart it's list of tweens. Maybe a repeatCount or something like that.

   Posted 1 year ago #
4. 

   Daniel
   Primary Feather

   The next Sparrow version makes this easier, as it allows tweens to loop:

   tween.loop = SPLoopTypeReverse;
   // or
   tween.loop = SPLoopTypeRepeat;

   You can grab it via SVN, if you can't wait

   Posted 1 year ago #
5. 

   marwic
   Member

   Daniel, that sounds nice. Will that work when you have a series of tweens that you want to repeat? Ie

   1. run tween one ,then
   2. run tween two, then
   3. goto 1

   I'm thinking it should be juggler.loop = SPLoopTypeRepeat as well?

   (Disclaimer: I'm new to Sparrow so I'm probably missing some stuff)

   Posted 1 year ago #
6. 

   baike
   Moderator

   You can do this if you want:

   - (void)toggleTween {
      SPTween *tween = [SPTween tweenWithTarget:myQuad time:2];
      [tween animateProperty:@"y" targetValue:((SP_IS_FLOAT_EQUAL(myQuad.y, 0)) ? 100 : 0)];
      [self.stage.juggler addObject:tween];
      [[self.stage.juggler delayInvocationAtTarget:self byTime:tween.time] toggleTween];
   }

   Posted 1 year ago #
7. 

   marwic
   Member

   balke, clever!

   Works really good plus I don't have to mess with event handlers.

   Posted 1 year ago #

RSS feed for this topic

Reply

You must log in to post.