JFree Graphics2D Tester is a visual tester for implementations of Java2D's Graphics2D class. The program generates a pre-defined set of outputs for any provided subclass of Graphics2D that can be compared against a known good result. The following libraries (as well as others) can be tested this way:

• JFreeSVG
• JFreePDF
• FXGraphics2D
• SkijaGraphics2D
• SkikoGraphics2D

By running through the features of Graphics2D systematically, this test kit is able to highlight areas of weakness in a particular implementation. The goal is to drive improvements in the available implementations.

The output of the Graphics2D target under test must be manually compared against the expected ("correct") output. The expected output can be generated by running the test program against the Graphics2D instance used by Java2D itself when drawing to a BufferedImage. For example, the following output is generated with Java 20 on MacOS:

The test kit uses several third party libraries:

• ZXing - used to create a QR code which is (a) part of the test and (b) provides a link to the Graphics2D implementation under test;

• JFreeChart - used to create a sample 2D chart;

• Orson Charts - used to create a sample 3D chart;

• SteelSeries-Swing - used within the Java Swing UI demo to draw a dial.

Graphics2D Tester is free software under the terms of the GNU General Public License version 3 (GPLv3) or later. The license file (LICENSE) is included in this distribution.

Please note that Graphics2D Tester is distributed WITHOUT ANY WARRANTY; without even 
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  
Please refer to the license for details.