Fuzzy brushes...

Steve Lime steve.lime at DNR.STATE.MN.US
Wed Dec 14 10:17:49 EST 2005


Remember it is only available for the moment in the simple case mentioned below. I will make more generally available tonite.

Steve

>>> "Ed McNierney" <ed at topozone.com> 12/14/05 6:32 AM >>>
Steve -

I had been meaning to offer to do some testing; thanks for the post.
I'll download and take a look today.

	- Ed

Ed McNierney
President and Chief Mapmaker
TopoZone.com / Maps a la carte, Inc.
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
Phone: +1 (978) 251-4242
Fax: +1 (978) 251-1396
ed at topozone.com 

-----Original Message-----
From: UMN MapServer Developers List [mailto:MAPSERVER-DEV at LISTS.UMN.EDU]
On Behalf Of Steve Lime
Sent: Wednesday, December 14, 2005 1:05 AM
To: MAPSERVER-DEV at LISTS.UMN.EDU
Subject: [UMN_MAPSERVER-DEV] Fuzzy brushes...

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    



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