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

Mon Nov 23 03:15:44 EST 2009

Me too ;-).
Unfortunately this is not the first thing I'm going to work on, first
need to make the current functionality work with canvas.

But you can follow the progress by checking my sandbox on
http://dev.openlayers.org/sandbox/krisgeus/openlayers

I added 2 examples already:
http://dev.openlayers.org/sandbox/krisgeus/openlayers/examples/tilecache
Canvas.html
and
http://dev.openlayers.org/sandbox/krisgeus/openlayers/examples/transitio
nWithCanvas.html

If you find any bugs or strange behavior please let me know.

Cheers Kris

-----Original Message-----
From: Adam Ratcliffe [mailto:adam.ratcliffe at gmail.com] On Behalf Of Adam
Ratcliffe
Sent: Monday, November 23, 2009 9:14 AM
To: Kris Geusebroek
Cc: users at openlayers.org
Subject: Re: [OpenLayers-Users] First try with html5 canvas for layers

OK, that makes sense.  Will be interesting to hear more of how this  
works out with a browser-based database.

Cheers
Adam

On 23/11/2009, at 8:43 AM, Kris Geusebroek wrote:

> Hi Adam,
>
> As Chris rightly point out there is already a canvas implementation  
> of the OpenLayers.Renderer which can be used instead of VML or SVG  
> renderer.
> My changes for using canvas in OpenLayers are currently  
> concentrating on the other layer types like WMS or Grid layers.
>
> Cheers Kris
>
>
>
>
> -----Original Message-----
> From: adam.ratcliffe at gmail.com [mailto:adam.ratcliffe at gmail.com] On  
> Behalf Of Adam Ratcliffe
> Sent: Saturday, November 21, 2009 1:54 AM
> To: Kris Geusebroek
> Cc: users at openlayers.org
> Subject: Re: [OpenLayers-Users] First try with html5 canvas for layers
>
> Hi Kris,
>
> I'm fairly new to OpenLayers and assumed that when creating a vector
> layer for use with wfs-t that the layer features would be rendered
> using either SVG or VML, thus allowing for the full range of mouse
> interactions that other DOM elements support (click, mouseover,
> mouseout etc).
>
> With the canvas implementation how do you support edting of a polygon
> for instance?
>
> Cheers
> Adam
>
> On Sat, Nov 21, 2009 at 1:32 PM, Kris Geusebroek
<kgeusebroek at xebia.com 
> > wrote:
>> Hi Adam,
>>
>> I think it doesn't make a difference in the current way OpenLayers  
>> works
>> other then replacing a lot of div's by a single canvas. Nothing to do
>> with interactivity I guess.
>>
>> The current div based vector layer can be used together with wfs-t or
>> getfeatureinfo request to make it interactive.
>>
>> And together with the refresh strategy (in trunk) you can make it  
>> look
>> like you are following the changes in data near real time.
>>
>>
>> Perhaps I misunderstood your remark. If so feel free to contact me
>>
>> Cheers Kris
>>
>> -----Original Message-----
>> From: users-bounces at openlayers.org
[mailto:users-bounces at openlayers.org 
>> ]
>> On Behalf Of Adam Ratcliffe
>> Sent: Saturday, November 21, 2009 12:45 AM
>> To: users at openlayers.org
>> Subject: Re: [OpenLayers-Users] First try with html5 canvas for  
>> layers
>>
>> Hi Kris,
>>
>> Am I correct in thinking this technique would be useful for  
>> displaying
>> read-only vector data only?  Or are you considering an approach such
>> as overlaying a transparent image map to allow interactivity?
>>
>> Cheers
>> Adam
>>
>> On Thu, Nov 19, 2009 at 8:58 PM, Kris Geusebroek
<kgeusebroek at xebia.com 
>> >
>> wrote:
>>> 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:
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> Hi All,
>>>>
>>>>
>>>>
>>>> I'm currently investigating the
>>>> possibilities of integrating html5 functionality into openlayers.
>>>>
>>>> My first try is using canvas for a layer
>>>> instead of div's
>>>>
>>>>
>>>>
>>>> I've setup a sandbox which you can
>>>> use to have a look:
>>>
>>
http://dev.openlayers.org/sandbox/krisgeus/openlayers/examples/tilecache
>>> Canvas.html
>>>>
>>>>
>>>>
>>>> This is the first example to show it's
>>>> possible ;-). Only features now are zoom and pan without the resize
>>> transition effect.
>>>>
>>>> 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
>>> _______________________________________________
>>> Users mailing list
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>>> http://openlayers.org/mailman/listinfo/users
>>>
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