The big picture
Processing is all of the following:
- A Java-based programming language
- An integrated development environment
- A core collection of useful Java classes
- A growing collection of libraries
- A community of developers
Simple Processing programs can be written without the “overhead” of Java classes, constructors, exceptions, or events. Almost all Processing programs are written using a succinctly documented API.
The UNCA picture
Processing has been used in CSCI 182 and its predecessor CSCI 273 (ST: Processing) since the Spring 2009 semester. These courses have always been considered an appropriate prerequisite for CSCI 202.
The detailed picture
The Processing IDE has a preprocessor that transforms Processing into Java.
The preprocessor adds appropriate modifiers, such as public,
to method definitions. It also makes minor source code changes such as
changing Processing-style casting, int(x), to
calls to Processing methods, PApplet.parseInt(x),
and
changing Processing-style colors, #A52A2A, to
integers, 0xFFA52A2A.
Most importantly, the preprocessor wraps the Processing program
inside a Java class defintion.
This Java program must import and extend the PApplet
class which is implemented in the jar file
core.jar distributed with Processing.
The PApplet has a
well-documented Javadoc file
that describes most of the operators of the Processing API.
Processing without its IDE
It is possible to write Processing programs using plug-ins for either Eclipse or NetBeans. Many programmers prefer these IDE’s because they make the task of writing and debugging large programs easier.
processing.js
In the first version of Processing, Processing programs could be
exported as Java applets that would executate in browsers with a
Java plug-in. However, in Processing 2, Processing programs
are run inside browsers using a JavaScript interpreter.
The program we discussed earlier is running below.