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

[Thomas Bonfort]

> Is there a way to disable antialias support with the agg renderer when
> drawing vector symbol based pattern fills?

Not that I know of.

> 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.)

yes, the antialiasing will almost always cause unwanted results if you
want your symbols to fit together at tile borders.
why not use the dedicated hatch symbol in this case ?


>
> 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


that symbol seems invalid to me, it creates 4 lines with no length,
and thus aren't rendered. GD assumed in this case that you wanted to
render a single pixel, AGG will not make this assumption and skip the
shape

regards,

thomas