Re: [Plib-devel] ssg animation

[Steve B. <sjb...@ai...>]

> Dave McClurg wrote:
> 
> Proposed changes:
> 
> ssgSelector would allow more than 32 frames by adding a max_kids param to the constructor
> 
>   ssgSelector ( int max_kids = 32 ) ;
> 
> the derived classed ssgRangeSelector and ssgTimedSelector would also take this param.

What about the current ability (which I use quite a bit) to pass an integer mask
with one bit per child object to enable you to select multiple child objects at
once?

> also, i would like to move this
> 
>   _ssgFrameCounter++ ;
> 
> from the top of ssgCullAndDraw() to the bottom of ssgCullAndDraw() because i want
> the animation rate to be based on logic frames and not render frames.

Yes - that's becoming important.

I was planning on making a new member function in ssgTimedSelector to allow you
to ask for either 'realtime' of 'frame-locked' animation.

There are cases when each is useful - and I'd like to mix them in the same
application sometimes.

> I'll just call ssgSetFrameCounter(fc) before calling ssgCullAndDraw().

That'll work in the short term.

> My logic frames are scheduled with a timer so that I always have 60 logic frames
> per second regardless of my render frame rate.  My animation plays correctly
> on slow machines and fast ones.  I prefer this over non-determistic simulations
> where the number of logic frames varies and uses floating point time intervals.

Yes - but there are times when frame-locked synchronisation is *CRITICAL*.

One example is in a weather simulation model we have at work that does
lightning bolts.  You need the lightning bolt to appear as briefly as
possible - yet never NOT happen because the previous frame took too long
to render.  To make the lightning look brighter, we do the visual trick
of pre-rendering a black lightning bolt, then doing the white one and
then another black one.  Its CRUCIAL that each of those three things
lasts just one frame - irrespective of the elapsed wall-clock time.

Anyway - doing this per-object rather than for the entire program
seems crucial to me.
 
> Please tell me your thoughts

Wibble, wibble, wibble.

  -- You did ask.  :-)


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