[mapserver-users] AGG renderer: Is there a way to disable the antialias feature with pattern brushes?

[Tamas Szekeres]

Håvard,

I guess it wouldn't be so straighforward to have the renderers work on a
common image format to provide this kind of co-operation. Currently the
imageObj structure contains renderer specific information and those may use
internal buffers to render the image.

At the moment I would see 2 options to provide specifying exact fill
patterns;

1. Change the AGG driver to have an option to render the pattern tile images
by using GD.
2. Modify the behaviour of rendering the pixmap (image) symbols so that the
pixel colors would take over the colors of the style.

With regards to the HATCH symbols it's not so usable in my case, as I'd
require to specify the symbols in that way which can be used with the
MapInfo data and the STYLEITEM "AUTO" settings. Since the MapInfo patterns
are mapped to single SYMBOL definitions (like mapinfo-brush-27 etc.) I
cannot rely on further settings of the style (like angle and width) and the
SYMBOL definition should be "self-contained".


Best regards,

Tamas



2009/10/19 Havard Tveite <havard.tveite at umb.no>

> Dear Tamas,
>
> I also miss the possibility to mix AGG's superb rendering of lines
> and points with non-anti-aliased vector polygon fills (I don't think
> everything can be solved using HATCH yet).
>
> Since AGG does not seem to support anti-aliased rendering, I thought
> about the possibility to allow some layers to be rendered with GD and
> some with AGG, and I suggested this in:
> <URL:
> http://lists.osgeo.org/pipermail/mapserver-dev/2008-December/007995.html>
>
> There were objections to this:
> <URL:
> http://lists.osgeo.org/pipermail/mapserver-dev/2008-December/007997.html>
>
> Håvard
>
> Tamas Szekeres wrote:
>
>> Folks,
>>
>> Is there a way to disable antialias support with the agg renderer when
>> drawing vector symbol based pattern fills?
>> I've just wanted to construct some of the pre-defined mapinfo fill
>> patterns (see image attached) but it seems the results are quite different
>> by using the agg and gd renderers (the latter is the desired result).
>> Another issue with this kind of antialiased drawing is that we may encounter
>> glitches at the tile borders (for example when drawing hatches this way.)
>>
>> The symbol definition of this one looks something like:
>>
>> SYMBOL
>>  NAME 'mapinfo-brush-62'
>>  TYPE VECTOR
>>  POINTS
>>    0 1
>>    4 5
>>    7 2
>>    -99 -99
>>    4 1
>>    4 1
>>    -99 -99
>>    0 5
>>    0 5
>>    -99 -99
>>    0 7
>>    0 7
>>    -99 -99
>>    2 7
>>    2 7
>>    -99 -99
>>    4 7
>>    4 7
>>    -99 -99
>>    6 7
>>    6 7
>>  END
>> END
>>
>>
>>
>> Best regards,
>>
>> Tamas
>>
>>
>> ------------------------------------------------------------------------
>>
>>
> --
> Håvard Tveite
> Department of Mathematical Sciences and Technology, UMB
> Drøbakveien 31, POBox 5003, N-1432 Ås, NORWAY
> Phone: +47 64965483 Fax: +47 64965401 http://www.umb.no/imt/
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/mapserver-users/attachments/20091021/b9048449/attachment.html