Fuzzy brushes and antialiased lines

[Steve Lime]

This support is akin to the brush support already in MapServer for circles and such. It's just a slightly different way to build the brush. It has no relationship to carto lines. All line brushes are cached in a imageCache tied to a symbol set (and mapfile). If you have used circle brushes before within java then these would work too.

Steve

>>> Umberto Nicoletti <umberto.nicoletti at GMAIL.COM> 12/19/05 1:45 AM >>>
Daniel,
is it thread safe so that I can use it in Java Mapscript? I have tried
Cartoline symbols before, but they crash my VM every with subsequent
request.

Thanks for you attention,
Umberto

On 12/16/05, Daniel Morissette <dmorissette at dmsolutions.ca> wrote:
> As promised in the 4.8.0-beta3 release announcement a few minutes ago,
> here is a bit more info about the fuzzy brushes and antialiased lines
> support that was just added.
>
> First, here are Steve's test mapfile and results:
>
>    http://maps.dnr.state.mn.us/testing/brushes/test.map
>    http://maps.dnr.state.mn.us/testing/brushes/test.png
>
> I also copied below from the first message in the "Fuzzy brushes..."
> mapserver-dev thread that describes how to use the new feature.
>
> Daniel
>
>
> -------- Original Message --------
> Subject: [UMN_MAPSERVER-DEV] Fuzzy brushes...
> Date: Wed, 14 Dec 2005 00:05:18 -0600
> From: Steve Lime <steve.lime at DNR.STATE.MN.US>
> Reply-To: Steve Lime <steve.lime at DNR.STATE.MN.US>
> To: MAPSERVER-DEV at LISTS.UMN.EDU
>
> In case anyone would like to test I have hooked up the fuzzy brush
> generator in mapgd.c for the most trivial line drawing case (no symbol
> defined). To use:
>
> 1) define a 24-bit output format, IMAGETYPE 'png24' works nicely
> 2) define a simple style definition for a line layer (or polygon
> outline) like so:
>
>    STYLE
>      WIDTH 3
>      COLOR 255 0 0
>      ANTIALIAS TRUE
>    END
>
> 3) set TRANSPARENCY ALPHA to enable alpha blending
>
> Caveats:
>
>   - brushes need to be odd sized. That requirement is enforced in the
> brush builder which detects even sized requests and rounds up. Symbol
> scaling should work just fine.
>
>   - you'll notice that the line "fades" in at the start which is due to
> the  transparent nature of the brush. Adjusting the default "hardness"
> may minimize that.
>
> That should do it. I will enable for circles layers and other instances
>   where it makes sense (circle symbols, simple symbols with dash
> patterns and so on) ASAP. I also will enable image cache use in the most
> simple case which may help performance a bit.
>
> Note, I hope to do away with 3) (there is a bug filed) but can't yet
> because of a problem in the image merging code in mapgd.c (not mine old
> code for a change).
>
> Steve
>