Could someone post a summary of where this discussion is at? It's hard to tell given the length of the thread...
Steve -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Brent Fraser Sent: Sunday, December 11, 2011 6:24 PM To: Stephen Woodbridge Cc: [email protected] Subject: Re: [mapserver-users] GEOMTRANSFORM LABELPNT example Steve, I agree the new features should be driven from specific use cases, but I like to expand designs to handle unforeseen uses (hopefully without adding complexity). So I prefer GEOMTRANSFORM (getCentroid(labelpoly)) instead of GEOMTRANSFORM LABELBBOXCENTROID My use cases for expanded GEOMTRANSFORM (from an earlier email with Steve L): ------------------- The solution of using a STYLE with GEOMTRANSFORM got me thinking of using the technique to solve some of the labeling challenges: 2. Place polygon annotation on/inside boundary line (http://trac.osgeo.org/mapserver/ticket/1592 point 8.) - label the line geometry resulting from GEOMTRANSFORM (buffer([shape], -3)) of the original polygon 5. Place line anno above (or below) when using ANGLE FOLLOW - label the line geometry resulting from GEOMTRANSFORM (buffer([shape], 5)) of the original line - useful for labeling rivers above their geometry Currently the LABEL object uses the original geometry. Do you think it would be possible to [optionally?] use the GEOMTRANSFORMed geometry? Similarly, would it be possible to have the LABEL's convex hull (or a buffer the character boxes?) used as a clipping polygons of the layer's geometry to address: 8. Erase layer's geometry (but not other layers) under label - possible syntax: GEOMTRANSFORM ( clip( [labelpoly] ) ) - useful for labeling contours ---------------- Best Regards, Brent Fraser On 12/11/2011 3:02 PM, Stephen Woodbridge wrote: > It seems to me that we should develop specific use cases that we are > trying to support. > > We have one that this feature was developed for, and that is as Steve > L mention for labeling Highway Shields were the actual shield may be > composed of multiple parts that need to be be super imposed relative > to a label point, if I recall the details of that discussion without > looking it up again. > > Ian, I think the point you are looking for is different. That would be > the centroid of the label polygon. That point may or may not be > coincidentally the same as the LABELPNT under some small set of > configuration parameters but by no means guaranteed to be the same. > > I think that these points might be the same is you have a single line > of text, ie: not wrapped, and POSITION CC and probable ANGLE 0. But I > have not had time to test. > > -Steve W > > On 12/11/2011 4:18 PM, Ian Walberg wrote: >> So is it expected that labelpnt generates a point with its center at >> the middle of the bounding rectangle of the text? >> >> Thanks >> >> Ian >> >> >> -----Original Message----- From: >> [email protected] >> [mailto:[email protected]] On Behalf Of Brent >> Fraser Sent: Sunday, December 11, 2011 1:02 PM To: thomas bonfort Cc: >> [email protected] Subject: Re: [mapserver-users] >> GEOMTRANSFORM LABELPNT example >> >> Thomas, >> >> I tracked it down to the LABELCACHE setting. >> >> LABELCACHE ON gives the expected results LABELCACHE OFF gives my >> old blue-dot-on-the-left results. >> >> See attached PDFs. >> >> Best Regards, Brent Fraser >> >> >> On 12/11/2011 1:05 PM, thomas bonfort wrote: >>> There might have been a bug in the initial implementation. trying >>> it out with current trunk gives me the expected result, unless I'm >>> missing something. >>> >>> >>> On Sun, Dec 11, 2011 at 20:44, Brent >>> Fraser<[email protected]> wrote: >>>> 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<[email protected]> 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 >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> _______________________________________________ >>>>>> mapserver-users mailing list [email protected] >>>>>> http://lists.osgeo.org/mailman/listinfo/mapserver-users >>>> >>>> >>>> >>>> _______________________________________________ mapserver-users >>>> mailing list [email protected] >>>> http://lists.osgeo.org/mailman/listinfo/mapserver-users > > _______________________________________________ > mapserver-users mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/mapserver-users > _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users
