Java Tools
for
Experimental Mathematics

java2d

Java2d

This package provides a 2D scene graph api based on the rendering capabilities of java.awt.Graphics2D.

The basic element in the 2D scene is a SceneNode that can provide all ingredients necessary to draw it: a Shape that can be filled with a certain Paint, whose outline can be drawn using a certain Stroke etc.

A Stroke in Java2D provides a way to create a 2-dimensional shape (that can be filled with a paint) out of the (in principle infinitely thin) 1-dimensional outline of a shape, in order to make it visible. Thus, Java2D provides ways to render 2- and 1-dimensional objects. In technical or mathematical drawings often also 0-dimensional geometries (points) need graphical representation. Therefore this package introduces (in analogy to a Stroke) the concept of a Stamp. A Stamp can generate paintable shapes out of a finite collection of points.

A SceneNode also can have a textual Annotation which is a collection of strings to be drawn at certain positions.

In addition, a SceneNode can have children, which allows for a scene that is a directed acyclic graph. Each scene node can have an affine transformation that describes its orientation with respect to its parents. All attributes like paint, stroke, font etc. can be null, which means that they are inherited from the scene hierarchy.

• An AppearanceChangeEvent can be passed along the hierarchy to inform viewers that some scene node has changed its look and therefore the scene needs repainting.
• One can register with a scene node for being informed when a DragEvent occurs, which means that the user is attempting to manipulate the node's geometry with some input device (like using a mouse drag).
• One can register with a viewer for the occurance of a ViewportChangeEvent. This can be used to create viewport-dependent geometry like coordinate axes.