[mapserver-users] GEOMTRANSFORM LABELPNT example

[Brent Fraser]

Thomas,
   See comments below.

Best Regards,
Brent Fraser


On 12/11/2011 12:26 PM, thomas bonfort wrote:
> I think this is all expected behavior, although the documentation may
> be incorrect.
>
> LABELPNT draws a marker on the geographic position the label is
> attached to. This corresponds to the center of the label text only if
> the label is in position CC.
I think that is what is intended but my original test case (using CC ) 
resulted in the LABELPNT rendered on the left side of the labelpoly, see 
http://lists.osgeo.org/pipermail/mapserver-dev/attachments/20110526/47c9bc8c/labelpnt-0001.png. 
   I had expected it to be coincident with the yellow circle and green 
cross.

>
> To draw a label at the center of the label text, another geomtransform
> would have to be implemented, named e.g. LABELBBOXCENTROID.
or maybe

GEOMTRANSFORM (centroid([LABELPOLY]))

>
> regards,
> thomas
>
> On Sun, Dec 11, 2011 at 19:34, Brent Fraser<bfraser at geoanalytic.com>  wrote:
>> Hey Jeff,
>>
>>   I've been looking into this too (not finished yet).  I'm using v6.0.1 and
>> can reproduce my original results (blue dot to the left) AND Ian's (grey dot
>> coincident with white dot).  Very strange.  My shapefile dataset gets
>> reprojected from geographic to UTM, so that may be causing the difference.
>>   I need to look into that...
>>
>> Best Regards,
>> Brent Fraser
>>
>>
>>
>> On 12/11/2011 10:57 AM, Jeff McKenna wrote:
>>> On 11-12-11 11:20 AM, Ian Walberg wrote:
>>>> Here is the map file we are using ms4w 3.0.3.
>>>>
>>>> We thought the larger grey circle should be drawn in the center of the
>>>> label text.
>>>>
>>>> What have we done wrong?
>>>>
>>>>
>>> I have done some testing on this on Windows, with MapServer trunk
>>> (6.1-dev), here are my findings:
>>>
>>> - I used Brent's original example styles (from
>>> http://osgeo-org.1803224.n2.nabble.com/GEOMTRANSFORM-labelpnt-location-td6408065.html)
>>> with Ian's FEATURE layer -->  Brent's "Blue Dot" LABELPNT with POSITION CC is
>>> now correctly placed in the center of the label text (so it seems this has
>>> been fixed in the code, but I can't find the ticket that says that)
>>> - If I change to POSITION LR (as in Ian's example layer) then I get Ian's
>>> issue (LABELPNT is placed at the geometry location, not in the center of the
>>> label text
>>> - but this is now an issue of understanding the developer's logic (from
>>> that thread SteveL says "Let me ponder this and get back to you. I think it
>>> makes sense to use the label point geotransform only with position CC so
>>> that it matches actual shape location.")
>>>
>>> That's all I know at this point (ha pun).
>>>
>>> -jeff
>>>
>>>
>>>
>>>
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