[OpenLayers-Users] Zoomify and fractional zoom

[Andreas Hocevar]

I see. So maybe you need to leave the original z assignement as-is
(without Math.round or Math.floor), and only change the lines that say

this.tierSizeInTiles[z]

to something like

this.tierSizeInTiles[z|0]

(z|0 being a more efficient way of saying Math.floor(z)).

Andreas.

On Wed, Jun 27, 2012 at 12:04 PM, David Régade <dregade at viewsurf.com> wrote:
> I tried Math.floor and the problem is the same. I'm not sure the problem
> comes from Math.round/floor because with my example, for an integer zoom
> value (3 for example), top left displayed tile is 256px width (thanks
> firebug). For a 3.4 zoom value should the top left tile image width be
> greater than 256px ?
>
> So if the displayed tile images are 256px for 3.4 zoom level, you need more
> tile to cover the layer extent in resolution associated to this zoom level.
> That's why on my axample, when you click on the button the displayed tile
> images are not centered as is it should be and another image tile (that
> doesn't exist) is required and tried to be drawn. Am I wrong ?
>
> Here is a screenshot of what I observed:
> http://david.regade.free.fr/openlayers/z3.4.jpg
>
> Regards
> David
>
>
> On 27/06/2012 11:41, Andreas Hocevar wrote:
>>
>> Try Math.floor instead of Math.round - currently the client zoom
>> implementation only supports oversampling, so you need the next
>> smallest zoom level.
>>
>> Andreas.
>>
>> On Wed, Jun 27, 2012 at 10:51 AM, David Régade<dregade at viewsurf.com>
>>  wrote:
>>>
>>> Hi,
>>>
>>> It can't be so easy. I fixed line 225 with:
>>>             var z = Math.round(this.map.getZoom());
>>>
>>> And another bug appeared line 201, same fix:
>>>             var z = Math.round(this.map.getZoom());
>>>
>>> However on this example, http://david.regade.free.fr/openlayers/, setting
>>> zoom to 3.4 doesn't generate javascript errors anymore but the result
>>> isn't
>>> correct. A tile is tried to be drawn and it shouldn't.
>>>
>>> I tried to trace where and why this tile is drawn but I'm to new to
>>> openlayers to find where the problem comes from.
>>>
>>> Regards
>>> David
>>>
>>> On 27/06/2012 08:05, Andreas Hocevar wrote:
>>>>
>>>>
>>>> I just see that there is a bug in Zoomify.js, line 225:
>>>>
>>>>             var z = this.map.getZoom();
>>>>
>>>> We need the integer of getZoom() here instead.
>>>>
>>>> Maybe you want to send a pull request with a fix?
>>>>
>>>> Andreas.
>>>>
>>>> On Tue, Jun 26, 2012 at 11:33 PM, David Régade<dregade at viewsurf.com>
>>>>  wrote:
>>>>>
>>>>>
>>>>> I get the last OpenLayers master and this feature doesn't work with the
>>>>> following example:
>>>>>
>>>>> http://david.regade.free.fr/openlayers/
>>>>>
>>>>> Is there something I'm doing wrong ?
>>>>>
>>>>> When setting up a fractional zoom (by clicking on the button for
>>>>> example)
>>>>> Firebug catches an error.
>>>>> Layer is resized but the tiles are not set correctly.
>>>>>
>>>>> David
>>>>>
>>>>>
>>>>> On 26/06/2012 16:32, Andreas Hocevar wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>> This is supported in OpenLayers master and the upcoming 2.12 release.
>>>>>>
>>>>>> Andreas.
>>>>>>
>>>>>> On Tue, Jun 26, 2012 at 3:12 PM, David Régade<dregade at viewsurf.com>
>>>>>>  wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Hi,
>>>>>>> We use openlayers to display large panoramas. We use ZoomifyImage to
>>>>>>> split
>>>>>>> original image in tiles and Zoomify layer to display these tiles.
>>>>>>> I would like to use fractionalZoom with Zoomify layer but this layer
>>>>>>> doesn't
>>>>>>> support this feature. The main goal is to able to resize displayed
>>>>>>> tiles
>>>>>>> for
>>>>>>> zoom level 3 from 2.5 to 3.4.
>>>>>>>
>>>>>>> Does anyone knows how to do that ?
>>>>>>>
>>>>>>> Thanks in advance
>>>>>>> --
>>>>>>> David REGADE
>>>>>>> _______________________________________________
>>>>>>> Users mailing list
>>>>>>> Users at lists.osgeo.org
>>>>>>> http://lists.osgeo.org/mailman/listinfo/openlayers-users
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>> _______________________________________________
>>>>> Users mailing list
>>>>> Users at lists.osgeo.org
>>>>> http://lists.osgeo.org/mailman/listinfo/openlayers-users
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>
>>
>>
>



-- 
Andreas Hocevar
OpenGeo - http://opengeo.org/
Expert service straight from the developers.