[mapserver-users] ANGLE AUTO labels with TRUETYPE and LINE
features. The text isdisplayed wrong.
bud at cirl.uoregon.edu
Thu Mar 28 19:11:16 EST 2002
I have some more clues regarding this behavior...
My MacOSX (which exhibits the bug) is using GD1.8.4 linked with Mapserver.
My Linux box (running the most recent Debian software [unstable]) is
I am almost certain that the bug is in the GD source file gdft.c in
the function gdImageStringFT(), which is responsible for invoking the
freetype library to draw a character at a time. The initial angle
calculated by mapserver is correct; mapserver appears to NOT be at
gdImageStringFT() probably incorrectly computes the proper x/y
coordinates for the individual characters, resulting in the
appearance of a bad angle.
My conjecture is that you are also running GD1.8.4.
You may ask, "How come other people running 1.8.4 aren't experiencing
this bug?" The probable answer is that their GD is compiled with the
-DHAVE_LIBTTF flag on, which will enable mapserver to use an
alternate function, gdImageStringTTF(), which does not have the bug.
This is why people to build mapserver or GD for freetype 1.x do not
experience this bug (Steve Lime mentioned this last fact in a
Sooooo.... I am going to try to build GD2.0.1 and see if I can get
mapserver to link with it and see if it works. It may also be
possible to fix the bug directly in 1.8.4, which may be desirable if
GD2.0.1 is full of other bugs.
Note that I was able to duplicate this bug without mapserver by
hacking the GD test file, gdtestft.c to draw angled text. The bug
reproduces quite nicely in isolation.
Dan "Bud" Keith - bud at otsys.com
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