[mapserver-users] Rotated TrueType Point Symbols - Issue

[thomas bonfort]

ttf rotation is fixed in trunk for agg. the point of rotation is the
centre of the symbol.

regards,
thomas

On Fri, Jan 2, 2009 at 17:29, Fawcett, David <David.Fawcett at state.mn.us> wrote:
> Donald,
>
> I have seen this same issue using MapServer 5.2.0.  I first noticed it
> when I was doing an attribute binding example, but I can confirm that it
> also occurs when using a fixed angle.
>
> When specifying a fixed angle of 0 or 360, the symbol lands correctly on
> the point.  An angle of 90 sets it off of the point to the left.  180
> puts it to the lower left, 270 is lower center, 359 is almost back on
> center.
>
> The more that I look at this, it really looks like it is This related to
> the proper centering of symbols.  My square .ttf character appears to be
> rotating around the lower left corner of the glyph.  When the symbol is
> placed unrotated, it is correctly centered on the point feature.  So,
> maybe the rotation point needs to be calculated the same way as the
> placement point.
>
> I was quickly trying to pull together a demo, so I abandoned the .ttf
> approach and used a pixmap symbol of an arrow.
>
> I think that it is likely a bug, I should have filed a bug report back
> then.  I will do so now if you aren't interested in doing it.
>
> David.
>
> -----Original Message-----
> From: mapserver-users-bounces at lists.osgeo.org
> [mailto:mapserver-users-bounces at lists.osgeo.org] On Behalf Of Donald
> Kerr
> Sent: Friday, January 02, 2009 9:58 AM
> To: mapserver-users at lists.osgeo.org
> Subject: [mapserver-users] Rotated TrueType Point Symbols - Issue
>
>
> I have created a number of TrueType symbols most of which are good
> enough when positioned on the map at their default centre point.
>
> There appears to be an issue when these are then rotated using ANGLE.
> They do not appear to rotate around their centre point which can make
> them look very odd when placed on the map.
>
> Please see attached images one showing without the ANGLE applied and the
> other with. If the symbol rotated around its centre point then the arrow
> would simply show pointing the other way (180 degrees).
>
> I tried to make a TTF symbol that had the head of the arrow in the
> centre in the hope that it would rotate on this point. It shows
> correctly when no ANGLE is applied i.e. the head of the arrow over the
> point on the map but, when rotated, the error in placement is
> exaggerated.
>
> Here are the CLASS and SYMBOL definitions:
>
> CLASS
>        NAME "benchMarkSymbol"
>        EXPRESSION "benchMarkSymbol"
>        STYLE
>                SYMBOL "benchMarkSymbol"
>                SIZE 12
>                MAXSIZE 12
>                MINSIZE 4
>                COLOR 0 0 0
>                ANTIALIAS TRUE
>                ANGLE [orientation]
>        END # STYLE
> END # CLASS
>
> SYMBOL
>        NAME 'benchMarkSymbol'
>        TYPE TRUETYPE
>        FONT OSMasterMapSymbols
>        FILLED false
>        ANTIALIAS true
>        CHARACTER '7'
> END # SYMBOL
>
> The question is, am I doing something wrong or is this a bug? If the
> latter, is there a workaround meantime? For me just now, I'd be happy if
> the symbol rotated around its centre - I could live with that as a
> workaround.
>
> In a previous thread that I started about positioning of LABELs, Thomas
> Bonfort said, "I'd be in favor of having a way to specify the anchor
> point, either by fixing it on 0,0 , or by specifying it alongside the
> symbol, eg ANCHORPOINT 0.3 2". I agree that this would be good for
> symbols too but it may present a problem with scaled symbols, especially
> TTF. If it's not a fixed size then how can an anchor point be specified?
>
> Many thanks.
>
> Regards,
>
> Donald Kerr
> _______________________________________________
> mapserver-users mailing list
> mapserver-users at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>