[ka-Map-users] Number of tiles displayed

[Paul Spencer]

Are you zooming to a specific area as the map loads?  Its possible  
that it could be triggering loading of tiles at the most-zoomed-out  
scale and then again at the requested extents.

But that wouldn't really account for what is happening here.  I'm not  
sure what would be causing this.

Possibly changing the size in startUp.js would cause some new tiles  
to be requested, but even if it re-requested all of them, it would be  
less than 180.

Paul

On 1-Aug-06, at 11:41 AM, Jorden Dunne wrote:

> Thanks Paul,
>
> I had made the images 300 x 200 on a map that is 600 x 500 and I am
> displaying one layer - the base. However it seems to be trying to pull
> 180 images when the map is loading. Here are the values that the
> variables are set to in config.php;
>
> $tileWidth = 300;
> $tileHeight =200;
> $metaWidth = 3;
> $metaHeight = 3;
> $metaBuffer = 40;
>
> The tiles are also being created as GIF's.
>
> The same index.html file is being used to serve both a full screen
> instance of kaMap and the 600 x 500 map, based on request  
> parameters the
> size of the map is altered in startup.js. Would this have an influence
> on the amount of images being requested?
>
> Thanks,
> Jorden
>
> -----Original Message-----
> From: Paul Spencer [mailto:pspencer at dmsolutions.ca]
> Sent: 01 August 2006 15:18
> To: Jorden Dunne
> Cc: ka-map-users at lists.maptools.org
> Subject: Re: [ka-Map-users] Number of tiles displayed
>
> Jorden,
>
> the number of tiles that are initially loaded depend on:
>
> 1) size of map in the page and tile size.  If your map is 600 x 400
> and your tile size is 200 x 200, you need a minimum of 3x2 = 6 tiles
> to fill the map.  ka-Map also adds tiles around the edge to ensure
> that as the user drags, there's something to fill in with.  This
> would typically add 3 more tiles in each direction so you end up with
> 6 x 5 = 30 tiles.  A 'full page' map can easily end up requesting 80
> tiles ...
>
> 2) number of discrete layers in the client (GROUPS on the server
> side).  For each one that is ON, multiple by the number above.
>
> 3) depending on the version of ka-Map you are using, it may load
> tiles for layers that are not ON
>
> 4) size of individual tiles depends on the output format you have
> chosen.  If you are using PNG24 or JPEG with a low compression, you
> will have 20-40kb tiles.  GIF and 8bit PNG (and high compression
> JPEG) will end up in the 8-20kb range.
>
> If you only have one layer and a large map, try starting the users
> off with a small map size and giving them a control to dynamically
> make it larger if they want to take the performance hit.
>
> If you have multiple layers and they are all on by default, try
> turning the extra layers off for the first load to prevent the extra
> tiles on initial page load and allow the users to turn them on as
> required.
>
> Cheers
>
> Paul
>
> On 1-Aug-06, at 9:44 AM, Jorden Dunne wrote:
>
>> Hi,
>>
>>
>>
>> Is there a way to specify the amount of tiles that will be
>> generated when the user loads kaMap. A lot of our users may still
>> be using dial-up and sometimes our map tries to load about 80
>> images/tiles. I had a look at tile.php but can't seem to see where
>> this can be changed.
>>
>>
>>
>> Thanks,
>>
>> Jorden
>>
>>
>>
>> __________________________________________
>>
>>
>>
>> Jorden Dunne
>>
>> IT / MIS
>>
>>
>>
>> Irish Broadband
>>
>> Unit 6B
>>
>> Sandyford Business Centre
>>
>> Sandyford Industrial Estate
>>
>> Dublin 18
>>
>>
>>
>> tel:          (01) 481 1495
>>
>> email:     jorden.dunne at irishbroadband.ie
>>
>>
>>
>>
>>
>> _______________________________________________
>> ka-Map-users mailing list
>> ka-Map-users at lists.maptools.org
>> http://lists.maptools.org/mailman/listinfo/ka-map-users
>
> +-----------------------------------------------------------------+
> |Paul Spencer                           pspencer at dmsolutions.ca   |
> +-----------------------------------------------------------------+
> |Applications & Software Development                              |
> |DM Solutions Group Inc                 http://www.dmsolutions.ca/|
> +-----------------------------------------------------------------+
>
>
>
>
>

+-----------------------------------------------------------------+
|Paul Spencer                           pspencer at dmsolutions.ca   |
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|Applications & Software Development                              |
|DM Solutions Group Inc                 http://www.dmsolutions.ca/|
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