Thanks, I think that'll do the trick!
It only works for Javascript types, right? I can't pass an image through the
state machine in the same way, can I? Doesn't matter, I can make it work with
strings, just curious.
--
Rick
On Jun 17, 2011, at 1:16 , Achim Breidenbach wrote:
> Hello Rick,
>
> in BoinxTV most of such time critical things that are triggered by events I
> implemented as a state machine in Javascript. A state machine is a program
> that has a certain state and keeps it for the next run loop. The state will
> only be changed if a certain condition is matched. In your case such a
> machine could look like this:
>
> var oldString = "";
> var currentString = "";
> var startTime = 0;
> var state = 0;
>
> function (__string string1, __string string2, __number animationTime)
> main (__number currentTime, __string newString, __number transitionDuration)
>
> {
> var animationTime = 0;
>
> switch(state)
> {
> case 0: // wait for new string
>
> if(oldString != newString){
> startTime = currentTime;
> currentString = newString;
> state = 1; // make transition to new string
> }
> break;
>
> case 1: // make transition to new string
>
>
> animationTime = (currentTime - startTime) / transitionDuration;
>
> if(animationTime >= 1.0){
> // transition is over
> oldString = currentString;
> state = 0; // wait for next string
> }
>
> break;
>
> default:
> state = 0;
> }
>
> var result = new Object();
> result.string1 = oldString;
> result.string2 = currentString;
> result.animationTime = animationTime;
> return result;
>
> }
>
> find attached a little composition where this code is embedded. Just change
> the text from the "Message" input field to make it transition to the next
> text.
>
> <text transition.qtz>
>
> The big advantage of such a state machine is, that you can add more states to
> it without breaking the others. even if there are states that jumps to other
> states only for certain conditions, you are always sure that the other parts
> don't get affected. Also you can easily trace the "state" variable within
> your code to see if you finally arrives at the start again. This programming
> pattern gives you a very robust code. In this case nothing can dusturb the
> transition animation. Only when the transition has finished a new text will
> be accepted.
>
> best,
>
> Achim Breidenbach
> Boinx Software
>
>
>
> On 17.06.2011, at 09:09, Rick Mann wrote:
>
>> I've been doing these on-screen graphics for a web channel that covers space
>> launches. We show a couple of different countdown clocks, as well as a block
>> of ascent parameters.
>>
>> But for the last nine minutes of a shuttle launch, there's not much to show.
>> I have a couple dozen events that occur at various times during the count. I
>> want to display each one as it occurs. An event is just a text string
>> describing the event ("APU Start," "Steering Test," etc.).
>>
>> My custom patch can either output each string on a output port, or output an
>> array of structures that has the string and the associated time. The former
>> is easier for me.
>>
>> How can I crossfade from the last event string to the next, especially when
>> they come in rapid succession (perhaps more quickly than the crossfade
>> duration)?
>>
>> I was doing a similar cross fade between a set of images, and it was a real
>> pain to build the structure for it.
>>
>> Thanks for any suggestions,
>> Rick
>>
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