[OpenLayers-Dev] Performance question

[Lance Dyas]

Lorenzo Becchi wrote:
>>
>> > The primary issues with supporting this are not issues that can be
>> > solved on the client side.   WMS layers from the same server can be 
>> told to composite on the WMserver ... if they were managed in the 
>> layer switcher as separate layers the user would get the controls but 
>> not the quick switch ... but much fewer images requested from the 
>> servers... it is about creating a good illusion.
>> These comma separated layers could be listed individually or like 
>> subfolders in a tree
>>  
>
> Actually quick switching from the same WMS server would be feasible if 
> we allow the interface to move up and down wms layers inside the same 
> OL layer.
> Then we just need to refresh the OL layer.
Layer shuffling( turning off a layer for example is instantaneous) as 
they are stored as separate graphics client side is fast and even the 
adding of a new layer to the mix is faster as the server is only 
processing that one...  but the server side composited, reordering or 
exclusion of a layer will be slow as it is processing/re-rendering all 
the combined layers..  its not "Quick" anymore. We get different benefits
>
> All this is still colliding with TileCache or ka-Map cache as it is 
> make poor sense to store/cache all layer combinations from one server.
>
indubitably
> ciao
> Lorenzo

>
>
> Lance Dyas wrote:
>> Christopher Schmidt wrote:
>>  
>>> On Sat, Jul 28, 2007 at 02:29:13PM +0100, Ludwig M Brinckmann wrote:
>>>  
>>>    
>>>>> In general, I would advise against having 11 seperate layers on a 
>>>>> map.
>>>>> It's possible that this really is neccesary, but in general, 11 
>>>>> layers
>>>>> is more likely to confuse the user: You're the map maker, make some
>>>>> decisions about how the map should look, and combine some of the 
>>>>> layers.
>>>>>               
>>>> Well, I think there are many situations where one would want to 
>>>> give a user,
>>>> which might not be the general public, a _lot_ of layers and I 
>>>> would argue
>>>> that OL should should support this.
>>>>           
>>> The primary issues with supporting this are not issues that can be
>>> solved on the client side.     
>> WMS layers from the same server can be told to composite on the 
>> WMserver ... if they were managed in the layer switcher as separate 
>> layers the user would get the controls but not the quick switch ... 
>> but much fewer images requested from the servers... it is about 
>> creating a good illusion.
>> These comma separated layers could be listed individually or like 
>> subfolders in a tree
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>>   
>
> .
>