[ka-Map-users] Same API, but map images instead of tiles

Mon Sep 19 13:31:01 EDT 2005

hi, re your perl port:
the extra options in the setup in tmap-config.pm <http://tmap-config.pm> to 
allow initial zoom extent and center are a great idea. 

other than that, was there any benefit? why not just use the php stuff? i do 
prefer perl, but i had been sticking with php for mapserver because better 
support and docs. 

re no tiles:
wouldn't that have a similar effect as increasing the tile size in 
config.php? because when i do that, there is a drastic decrease in 
performance. will your implementation avoid that? 

-brent

On 9/19/05, Stephen Woodbridge <woodbri at swoodbridge.com> wrote:
> 
> Paul Spencer wrote:
> > Hi Steve,
> >
> > my feeling on this is that by the time you've done all the changes
> > necessary to make it work without tiles, you won't have much ka-Map
> > left. I understand your rationale, but ... as you acknowledged, ka- Map
> > is for certain types of applications only.
> 
> OK, so I guess that raises the following questions to the community:
> 
> What are other people doing with respect to server side tile management?
> Are you managing it? How?
> 
> How are you pruning the tile cache?
> 
> What kind of algorithm are you using to decide what tiles to keep and
> what tiles to remove and is this tied to a total max. cache size.
> 
> > If you can come up with an alternate implementation that would bypass
> > the tiling stuff, I'd be willing to at least consider it, but it is
> > certainly not high on my priority list to look into it or support it.
> 
> I will consider that if I have some time to work on ka-map. Javascript
> makes me crazy and as you probably know I don't need more help pushing
> me in that direction! :)
> 
> Thanks,
> -Steve
> 
> > Cheers
> >
> > Paul
> >
> > PS what ever happened to the perl port of the tiling code?
> 
> It is here if anyone wants to use or work on it.
> http://www.where2getit.com/mum3/
> Since it was done as part of an evaluation, I have not kept the port up
> to date. If anyone wants to feel free to do that and contribute it to
> the ka-map site.
> 
> > On 19-Sep-05, at 12:09 AM, Stephen Woodbridge wrote:
> >
> >> Delfos, Jacob wrote:
> >>
> >>> Steve,
> >>> I can see your point of view, in the sense that when using a few heavy
> >>> raster layers, it's easy to get your server overloaded by tile-
> >>> requests.
> >>> But what would such a solution have to improve over Chameleon (and
> >>> others), which can be used in an almost no-page-refresh way? Also,
> >>>
> >>
> >> Simplicity for for one and an application that can be deployed with
> >> either tiles or not depending on the javascript loaded.
> >>
> >>
> >>> generating and serving out an image as large as a Ka-Map viewport for
> >>> every redraw is quite CPU and Bandwidth expensive... The client-side
> >>>
> >>
> >> I am thinking of generating the image of just the viewed portion of
> >> the viewport because in many applications the user does not need to
> >> pan. So if you user usage patterns are goto location, zoom in, zoom
> >> out, zoom out, pan, zoom in, zoom in, then you are not getting much
> >> use of the cache and you are loading way more tiles into the viewport
> >> than 7 mapserver image requests. If you done have the tiles already
> >> cached on the server, you still have to generate them, and bandwidth
> >> is higher for the tiles because of all the non- viewed tiles that are
> >> loaded.
> >>
> >> It really makes sense for some application but clearly not for all.
> >> If it is just a matter of changing the javascript that is loaded, the
> >> it can be switchable by the user if you want to export the control
> >> for that.
> >>
> >> Thank you for your comments.
> >>
> >> Anyway something to think about,
> >> -Steve
> >>
> >>
> >>> caching of tiles helps reduce this issue significantly.
> >>> But I agree that keeping application development separate from
> >>> deployment issues is beneficial.
> >>> Regards,
> >>> Jacob
> >>>
> >>>
> >>>> -----Original Message-----
> >>>> From: ka-map-users-bounces at lists.maptools.org [mailto:ka-map-
> >>>> users-bounces at lists.maptools.org] On Behalf Of Stephen Woodbridge
> >>>> Sent: 19 September 2005 02:50
> >>>> To: ka-map-users at lists.maptools.org
> >>>> Subject: [ka-Map-users] Same API, but map images instead of tiles
> >>>>
> >>>> Hi Paul,
> >>>>
> >>>> I really like a lot of what is happening with ka-map. It is great
> >>>> to see all the community effort going into ka-map.
> >>>>
> >>>> I was wondering what it would take to make it work without tiles as
> >>>> an option. The idea would be that most of the code and logic would
> >>>> be the same but instead of pulling tiles it would just request a
> >>>> single image. On a pan the current image would slide like the
> >>>> current code and a new image would be requested and replace the
> >>>> partially obstructed image from the pan operation when it is ready.
> >>>> I was thinking that this part (ie: tile vs map image rendering)
> >>>> could be broken into two separate models with a common API and then
> >>>> depending on which was used you would get different rendering
> >>>> behavior.
> >>>>
> >>>> Why would anyone want this?
> >>>>
> >>>> 1) less server requests
> >>>> 2) no need for tiles and managing the tiles and disk space
> >>>> 3) maintains the rich no page refresh UI
> >>>> 4) would allow richer server side image manipulation than exists
> >>>> today because of the need to generate generic tiles.
> >>>> 5) separates application development from deploy concerns and issues
> >>>> 6) would allow ka-map to do something that google can not do
> >>>>
> >>>> Anyway, I thought I would float the idea and see what you had to
> >>>> say. Also I'm interested if others on the list think there would be
> >>>> value for something like this.
> >>>>
> >>>> -Steve W.
> >>>> _______________________________________________
> >>>> ka-Map-users mailing list
> >>>> ka-Map-users at lists.maptools.org
> >>>> http://lists.maptools.org/mailman/listinfo/ka-map-users
> >>>>
> >>>>
> >>
> >> _______________________________________________
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> >> 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/|
> > +-----------------------------------------------------------------+
> >
> >
> >
> >
> >
> 
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