Re: Optimization ideas (was Re: 64 bit version of Quesa)

[Roger H. <rog...@mi...>]

On 27 Feb, 2007, at 03:08, James Walker wrote:

> I was looking at the view state stack, and wondered if we really need
> the attributeSet member of TQ3ViewStackItem.  It causes a
> Q3Object_Duplicate call every time we push the stack, and it looks  
> like
> it's only there to support Q3View_GetAttributeState and
> Q3View_GetAttributeSetState.  Internally, we only call
> Q3View_GetAttributeSetState when writing view hints, and never call
> Q3View_GetAttributeState.  So I would think that whenever
> Q3View_GetAttributeState or Q3View_GetAttributeSetState is called, we
> could just build an attribute set on the fly from the various  
> attribute
> members of TQ3ViewStackItem.  Anyone see a problem with that?


I am not sure how much generality we would lose by doing this. I did  
come
across a program which included custom attributes in its data which I
picked up on in the Microspot Renderer. I do use lots of custom  
attributes
but our ones do not affect the rendering. I would rather use custom  
groups
or custom geometries to do those sorts of things.

I think we can check if there any other attributes which we don't  
understand.
If there are some then we proceed as now, otherwise we do as you  
suggest.
Hopefully the former case will be very rare. Maybe we could have a  
flag to
say if there are currently any custom attributes there, and only do  
the full
check when the attribute set gets changed.

I agree we do not want to be calling Q3Object_Duplicate for every group
in the data.

Roger.