Fuzzy brushes...

[Steve Lime]

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