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

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

On 27 Feb, 2007, at 17:34, James W. Walker wrote:

>
> On Feb 27, 2007, at 3:23 AM, Roger Holmes wrote:
>
>> 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 ay 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.
>
> I'm not sure how any custom attributes would get in that attribute
> set.  It looks like the only way an attribute is added to that set is
> by e3view_stack_update_attribute, which is called by
> e3view_stack_update only for specific known attribute types.

Well that's fine then. I thought there was a way of adding attributes
to the view object itself and that was what we were talking about.

So carry on.

Roger.