[Chameleon] tiff hang
Bart van den Eijnden
bartvde at xs4all.nl
Wed Dec 8 15:18:51 EST 2004
Assefa and list,
if I use this approach the 24 bit transparency problems in Internet
Explorer (grey background) are also gone.
I reported those problems in the Mapserver bugzilla:
http://mapserver.gis.umn.edu/bugs/show_bug.cgi?id=1089
Is this explainable for you guys?
Best regards,
Bart
On Wed, 08 Dec 2004 15:06:59 -0500, Yewondwossen Assefa
<assefa at dmsolutions.ca> wrote:
> Ken,
>
> Thanks for testing.
>
> AFAIK, the changes would only affect the Query widget if it is used with
> the parameters HIGHLIGHTRESULTS and PERSISTENTRESULTS. Maybe Paul can
> comment on other widgets that I may have overlooked.
>
> As for the drawmap.php, It does several functionnalities (every thing
> drawn in chamelon like map, scalebar, keymap) pass trough that function.
> The idea behind it is that if you assigning a URL to the image source
> (http::../drawmap.php?...), the main application page does not need to
> wait for the map to be drawn to load completly and thus It is supposed
> to give a better "smooth" looking apps.
>
> Your are the 2nd person who tried this solution and reported that the
> application was faster considerably. When using the drawmap.php method,
> there is a time cost associated with calling the server, loading the
> session and then drawing the map. I would have imagined that this
> solution would improve the rendering time slightly (since session
> loading and call to the server are cut) but I am surprised a bit to know
> that It has considerable effect since I always thought that the main
> bulk of the time is taken by the map drawing. I guess a good profiling
> might give us a better understanding.
>
> Anyhow I entered a bug 893 on this :
> http://www.maptools.org/bugzilla/show_bug.cgi?id=893
>
>
> Later,
>
>
> Ken-ichi wrote:
>
>> Wow, not only did that solve my problem, but it increased map rendering
>> speed considerably, even with no TIFFs! Thanks, Assefa and Paul.
>> Adding a flag in the widget tag to do this would be really helpful.
>> Are there any widgets that don't work with this adjustment, i.e. can I
>> alter our "production" copy of Chameleon and expect other Chameleon
>> projects on the server to work ok? What exactly is the purpose of
>> drawmap.php anyway?
>> Thanks again.
>> -Ken-ichi
>> Yewondwossen Assefa wrote:
>>
>>> The changes are minmal : here is what I did :
>>>
>>> 1) MapDHTML.widget.php : in function GetJavascriptVariables (around
>>> line 468) :
>>> comment the 3 lines and add the 3 additional lines :
>>>
>>> //$url =
>>> WEBCOMMON."/wrapper/drawmap.php?map_session_mode=$nMapSessionMode&run_query=0&".SID.$szFatalImage;
>>> //if (!$bCWCJSAPI)
>>> //$url .= "&dummy=".urlencode(microtime());
>>>
>>> $oMap = $this->moMapObject->oMap;
>>>
>>> $img = $oMap->draw();
>>> $url = $img->saveWebImage();
>>>
>>> 2) in MapDHTML.js : function MapLayerDivImgOnLoad
>>>
>>> comment the line : //url = url + "&UniqId="+unique;
>>>
>>>
>>> Please give it a try and let me know.
>>>
>>> Paul, I think we can easily make this a configurable thing as far as
>>> mapdhtml is concerned. I think there might be a problem though with
>>> the new query widget that diplays the selected element (and keep the
>>> selection persitently) but It can also be solved with few changes.
>>> What I propose is that Ken do the tests and if it solves his problem,
>>> I will enter an enhancement bug on this with the changes required and
>>> we can implement it after that.
>>>
>>>
>>> Later,
>>>
>>>
>>> Paul Spencer wrote:
>>>
>>>> Ken,
>>>>
>>>> this is very strange. Chameleon is not aware of the image formats of
>>>> the underlying data, it just uses mapscript to do the drawing.
>>>>
>>>> Another solution to this problem may be to have the MapDHTML widget
>>>> render the map to a file and then load the image source in the page
>>>> rather than use drawmap.php.
>>>>
>>>> We did this for another client who was having a strange problem with
>>>> images half loading due to some sort of firewall problem (only in IE
>>>> strangely).
>>>>
>>>> I've cc'd Assefa since he was the one who sorted that out. Assefa,
>>>> can you post the solution to getting MapDHTML to render to a file?
>>>> Do you think we could make this a configurable parameter in the
>>>> MapDHTML widget (like DELAYDRAW="[true|false]" or something)?
>>>>
>>>> Cheers,
>>>>
>>>> Paul
>>>>
>>>> Ken-ichi wrote:
>>>>
>>>>> Thanks Paul. I tried loading drawmap.php directly, and that usually
>>>>> renders the map even when the Chameleon app hangs (though sometimes
>>>>> it hangs too), so I guess drawmap.php may not actually be the
>>>>> culprit. I made another, minimal app with just the ZoomIn, ZoomOut,
>>>>> Recenter, and MapDHTML widgets, and it still hangs on the tiffs, so
>>>>> I don't think it's any of my custom widgets that are mucking things
>>>>> up either.
>>>>>
>>>>> I am really at a loss here. The strangest thing about this is that
>>>>> if I convert the TIFF to an Erdas Imagine file (either in Erdas or
>>>>> with gdal_translate) everything works fine. What is it about tiffs
>>>>> that could possibly hang up Chameleon? Why would Chameleon even be
>>>>> aware of input file format? Don't MapServer and GDAL handle that?
>>>>> I know they're fine because a non-Chameleon phpMapScript app renders
>>>>> the map fine, as does the CGI.
>>>>>
>>>>> Argh.
>>>>>
>>>>> -Ken-ichi
>>>>>
>>>>> Paul Spencer wrote:
>>>>>
>>>>>> Ken,
>>>>>>
>>>>>> to debug drawmap.php, you need to grab the URL from the image in
>>>>>> the chameleon app and load it directly in your browser. You should
>>>>>> then see any error messages or debug output directly. Often,
>>>>>> problems with a broken map image are related to error messages (or
>>>>>> notices) being output before the image contents, thus creating a
>>>>>> corrupt image.
>>>>>>
>>>>>> If nothing shows up immediately on viewing the drawmap.php url, you
>>>>>> can then start to add some debugging code (echo) to drawmap.php to
>>>>>> try to discover what is going on.
>>>>>>
>>>>>> Cheers,
>>>>>>
>>>>>> Paul
>>>>>>
>>>>>> Ken-ichi wrote:
>>>>>>
>>>>>>> Hi list. A while ago I posted an issue I'd been having with
>>>>>>> rendering TIFFs in Chameleon
>>>>>>> (http://lists.maptools.org/pipermail/chameleon/2004-August/thread.html#1245),
>>>>>>> but I never really resolved it. Essentially, whenever I zoom in
>>>>>>> on a GeoTIFF so that the TIFF fills the whole map, Chameleon hangs
>>>>>>> and never displays the map image (I just get the spinner icon
>>>>>>> indefinitely and then a broken image icon behind it. Try zooming
>>>>>>> in on the DRG (Test Raster) at
>>>>>>>
>>>>>>> http://fisher.cnr.berkeley.edu/vtm/data/mapbrowse/
>>>>>>>
>>>>>>> to see what I'm talking about. I'm fairly sure this is a
>>>>>>> Chameleon issue, most likely with drawmap.php, because this
>>>>>>> mapfile renders just fine via the CGI, and with a rudimentary
>>>>>>> phpMapScript app like this one:
>>>>>>>
>>>>>>> http://fisher.cnr.berkeley.edu/~kueda/mapscript_browse.phtml
>>>>>>>
>>>>>>> The DRG is a 16M GeoTIFF from the California Spatial Information
>>>>>>> Library, so I don't think it's to blame. You can check out my php
>>>>>>> and MapScript config at
>>>>>>>
>>>>>>> http://fisher.cnr.berkeley.edu/~kueda/phpinfo_mapscript.phtml
>>>>>>>
>>>>>>> I'm running MapServer 4.4.0, GDAL 1.2.5, and PHP 4.3.9. Can
>>>>>>> anyone think of a reason this could be happening, or recommend a
>>>>>>> way to troubleshoot drawmap.php?
>>>>>>>
>>>>>>> -Ken-ichi
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Chameleon mailing list
>>>>>>> Chameleon at lists.maptools.org
>>>>>>> http://lists.maptools.org/mailman/listinfo/chameleon
>>>>>>>
>>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Chameleon mailing list
>>>>> Chameleon at lists.maptools.org
>>>>> http://lists.maptools.org/mailman/listinfo/chameleon
>>>>>
>>>>
>>>
>>>
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>
>
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