[OpenLayers-Users] First try with html5 canvas for layers

[Kris Geusebroek]

Hi Eric,

Indeed it's cool, thanks.
My goal was to write an application with open source technologies to
track cars driving around.
I wrote a prototype with geoserver and openlayers and this was
succesfull. The big problem was the memory consumption (especially in
IE) because of the large amount of DOM manipulation that is done when
panning and zooming and drawing vector's (the cars, with fills, stroke,
label etc.)

Since using a plugin is out of the question here I began investigating
the html5 canvas.
I know it's not supported in IE, but for me that was a good thing
because it gave me the opportunity to have the client choose a different
browser then IE.

My plans for the future of the app is to also use workers and the
browser database (to be able to store historical responses clientside to
draw a route the car has followed for the last 10 minutes or so)

Also I think the canvas gives us the opportunity to create a print
control or a save map as, because in the end it's just an image. (have
to combine the layer specific canvasses into one but that's easy ;-))

If you have any other ideas or see different opportunities let me know,
my client is fundning me to experiment with html5 so I might be able to
spent some time on other's feature requests ;-)

Cheers Kris


-----Original Message-----
From: Eric Lemoine [mailto:eric.lemoine at camptocamp.com] 
Sent: Thursday, November 19, 2009 6:53 AM
To: Kris Geusebroek
Cc: OpenLayers Users
Subject: Re: [OpenLayers-Users] First try with html5 canvas for layers

On Wednesday, November 18, 2009, Kris Geusebroek <kgeusebroek at xebia.com>
wrote:
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> Hi All,
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> I'm currently investigating the
> possibilities of integrating html5 functionality into openlayers.
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> My first try is using canvas for a layer
> instead of div's
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> I've setup a sandbox which you can
> use to have a look:
http://dev.openlayers.org/sandbox/krisgeus/openlayers/examples/tilecache
Canvas.html
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> This is the first example to show it's
> possible ;-). Only features now are zoom and pan without the resize
transition effect.
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> If anyone has remarks, ideas, feature
> requests, help offerings etc. Feel free to contact me.

This is cool!

May I ask what's your goal with displaying tiles using canvas? Is it
performance? I have never played with canvas so I'm interested to know
and talk about what it can bring to OpenLayers.

Thanks Kris,

-- 
Eric Lemoine

Camptocamp France SAS
Savoie Technolac, BP 352
73377 Le Bourget du Lac, Cedex

Tel : 00 33 4 79 44 44 96
Mail : eric.lemoine at camptocamp.com
http://www.camptocamp.com