[ka-Map-users] Re: Partial labels

[David Badke]

I have seen this happen when the cache gets out of sync with the map 
file. For example, if I generate a map at a given scale, then do 
something to the map file (change min/max when layer displays, for 
example), then load the map again, sometimes a label is cut off. 
Clearing the cache always fixes it. Could it be that the tile adjacent 
to the one with the partial label (that is, the one that should have the 
missing piece of the label) was generated without the label, and ka-Map 
just grabs it from the cache?

David


ramesh karra wrote:
> Thanks again paul!
>
> This is certainly not a problem about label at the
> edge of the map. The point is in the middle of a map
> and most likely is tile boundary problem because the
> label is at the tile boundary. But, as I mentioned
> before, not all labels in the tile boundary gets
> clipped.
>
> I will try to reproduce it with a small data set and
> will send you the data and the map file in couple of
> days. If it is OK with you I will directly send you
> the data(and not to the list).
>
> Thanks
> Ramesh
>
> --- Paul Spencer <pspencer at dmsolutions.ca> wrote:
>
>   
>> Hi Ramesh,
>>
>> The root of the problem is that mapserver renders
>> stuff right up to  
>> the edge of the map.  To fix rendering issues with
>> thick lines using  
>> 'circle' symbol (for instance), we have to render a
>> slightly bigger  
>> image and clip out the center of it to get lines to
>> match up (among  
>> other things).  This causes a problem with point
>> symbols and labels  
>> that are rendered close to the edge of the map.  In
>> MapServer 4.6,  
>> metadata was introduced to prevent text and symbols
>> rendering too  
>> close to the edge of the map.  This is controlled in
>> ka-Map's  
>> config.php file with $metaBuffer (default 10
>> pixels).
>>
>> MapServer 4.6 (final) should have support for the
>> metadata that  
>> supposedly fixes this problem.  However, I have seen
>> some examples of  
>> places where the label does get vertically or
>> horizontally clipped at  
>> a tile boundary.  I can't reliably reproduce the
>> problem so it is  
>> hard to fix.
>>
>> Do you have a small dataset that I could use to
>> reproduce the problem  
>> with a copy of your configuration?
>>
>> You can use the gimp to capture screenshots in
>> linux.  There are  
>> probably a ton of other ways.
>>
>> Cheers
>>
>> Paul
>>
>>
>> On 21-Mar-06, at 3:59 PM, ramesh karra wrote:
>>
>>     
>>> Thanks for the quick response Paul!
>>>
>>> I am using mapserver 4.6 and the class drawing the
>>> label is
>>> CLASS
>>>       NAME       "Points"
>>>
>>>       STYLE
>>> 	SYMBOL       7
>>>         COLOR        225 225 225
>>>         OUTLINECOLOR 255 000 000
>>> 	SIZE	     0
>>>       END
>>>
>>>       LABEL
>>> 	FORCE TRUE
>>>         COLOR 0 0 0
>>>         SHADOWCOLOR 255 255 255
>>>         SHADOWSIZE 1 1
>>>         TYPE TRUETYPE
>>>         FONT verdana
>>>         SIZE 8
>>>         ANTIALIAS TRUE
>>>         POSITION CC
>>>         PARTIALS FALSE
>>>         MINDISTANCE 0
>>>         BUFFER 0
>>>       END
>>>     END
>>>
>>> How do I capture the screenshot in linux?
>>>
>>> Thanks
>>> Ramesh
>>>
>>> --------------------
>>> Ramesh,
>>>
>>> there can definitely be a problem, but it actually
>>> depends more on
>>> mapscript version.  What version of mapserver are
>>>       
>> you
>>     
>>> using?
>>>
>>> Also, it may be pertinent to know what your label
>>> style is for the
>>> layer that is having problems.
>>>
>>> Finally, can you send a screenshot of the problem?
>>>
>>> Cheers
>>>
>>> Paul
>>>
>>> On 21-Mar-06, at 2:52 PM, ramesh karra wrote:
>>>
>>>       
>>>> Hi,
>>>>
>>>> I have kaMap ver 0.2 (Feb 7, 2006) and sometimes
>>>>         
>> I
>>     
>>> see
>>>       
>>>> partial labels. This seem to happen when the
>>>>         
>> label
>>     
>>> is
>>>       
>>>> split between two tiles. But it does not happen
>>>>         
>>> every
>>>       
>>>> time.
>>>>
>>>> Is this a known issue? Any solutions?
>>>>
>>>> Thanks
>>>> Ramesh
>>>>
>>>>         


-- 

David Badke
Humanities Computing and Media Center
University of Victoria, BC, Canada