Draw chart uder Windows and Linux without X Server

Everhood · Post by **Everhood** » Thu Dec 18, 2008 9:35 am

Hello all,

JFreeChart 1.0.11

Enviroment:
Server: Linux 8.0, tomcat5, no X Server started.

Windows

How can I get same draw quality on Linux?

Thanks!

Post by **david.gilbert** » Thu Dec 18, 2008 9:52 am

The output from Linux looks like it doesn't have antialiasing enabled. Not sure why that would be. Which Java runtime are you using?

Everhood · Post by **Everhood** » Thu Dec 18, 2008 9:55 am

java version "1.7.0"
IcedTea Runtime Environment (build 1.7.0-b21)
IcedTea Server VM (build 1.7.0-b21, mixed mode)

Post by **david.gilbert** » Thu Dec 18, 2008 10:10 am

OK, IceTea is based on OpenJDK but with the "binary blob" (non-open source code) removed and replaced with Free / Open Source alternatives. I think that the Java2D rendering is one area that Sun wasn't able to fully "open source" (because code was licensed from a third party) so there is some new Java2D code in there...so I guess what you are seeing is could be a bug in the new implementation. Their bug tracker is here if you want to report it:

http://icedtea.classpath.org/bugzilla/query.cgi

When I find some time, I'd like to get up to speed with IcedTea so I can make sure JFreeChart runs nicely on it. Hopefully I'll do that before the FOSDEM conference in Brussels in February (where many of the OpenJDK, GNU Classpath and IcedTea developers meet).

Everhood · Post by **Everhood** » Thu Dec 18, 2008 10:39 am

Thanks for quick answer, I'll try to install java from SUN.

Everhood · Post by **Everhood** » Thu Dec 18, 2008 5:47 pm

After installing

java version "1.6.0_10"
Java(TM) SE Runtime Environment (build 1.6.0_10-b33)
Java HotSpot(TM) Server VM (build 11.0-b15, mixed mode)

drawing is OK.

Post by **Taqua** » Thu Dec 18, 2008 6:40 pm

Actually, the JDK never made a claim that a certain default anti-aliasing setting is required. The defaults changed in the past and in most cases, they are purely platform dependent.

If you tell your Windows-System (or Linux, does not matter) to not perform any aliasing on graphics and fonts, you probably want your JDK to obey to that rule. At least on Windows, the JDK uses whatever you define as system-default in the control panel. For Linux, things are a bit more difficult thanks to a insane X11-Server API (or no X11-Server at all).

Therefore I would not claim it a JDK bug. You probably should provide a sensible default in your code.

@see http://java.sun.com/javase/6/docs/api/j ... rties.html
@see http://java.sun.com/javase/6/docs/techn ... flags.html

Post by **david.gilbert** » Thu Dec 18, 2008 7:50 pm

Taqua wrote:Therefore I would not claim it a JDK bug. You probably should provide a sensible default in your code.

JFreeChart sets the anti-aliasing hint by default. It's only a hint, so I guess a JRE could ignore it and still be compliant with the Java specification, but I'd still consider this a bug. Anyway, I'll dig deeper into IcedTea / OpenJDK soon and find out for sure...