gwt-geom is a port of the OpenJDK java.awt.geom package to work on GWT. It is especially useful for Constructive Area Geometry (CAG) manipulations. I use it for easily testing whether a screen click on an image is contained in a certain shape { for example shape.contains(x,y) }.
Drawing to screen can be done using a 2d drawing library (currently gwt-g2d is supported).
Most of the java.awt.geom package is available, as well as a few shapes from the java.awt package. I have chosen to rename the package to gwt.awt since we aren't providing all of java.awt and this helped me to ensure I wasn't using any unported code.
Run ant devmode to see a simple demo.
See ant -p for more options