Re: Caching with custom elements

[James W. W. <os...@jw...>]

On Feb 14, 2007, at 2:57 AM, Roger Holmes wrote:

>
> On 13 Feb, 2007, at 23:49, James Walker wrote:
>
>> In the renderers, I'm using a custom element to cache an optimized
>> version of a TriMesh.  The element contains an edit index along
>> with the
>> TriMesh reference, so that a stale cache can be detected.  That works
>> fine in principle, though there's a bug at the moment.
>>
>> But now suppose I have another similar custom element, say to cache a
>> triangle strip.  When I update the triangle strip, it bumps the edit
>> index, so the other cache becomes stale.  Which causes the other  
>> cache
>> to get updated, bumping the edit index, which makes the triangle  
>> cache
>> stale...
>>
>> How can I get out of this infinite loop?  The simplest way, I  
>> suppose,
>> would be to add a Q3Shared_SetEditIndex function, and use it when
>> setting these cache elements. Is there a more elegant way I haven't
>> thought of?
>> -- 
>
>
> I don't exactly understand what you are trying to do. You have an
> object A
> which has two caches B and C, both of which hold the edit index of A.
> Why would updating B or C update the edit index of A?

Because B and C are custom elements, and Q3Object_AddElement and  
Q3Shape_AddElement update the edit index.

> Or is C a cache of B? If so, C holds the edit indexes of A and B.

Elements don't even have edit indexes, only shared objects do.