Page 153 - Hacking Roomba

134 Part II — Fun Things to Do

Listing 7-1 Continued

void draw() {
background(51);
fill(0,0,255);
rectMode(CENTER);
rect(mouseX,mouseY, width/5,height/5);
}

When the Run button is clicked, the sketch content is embedded in a Java class, compiled, and
run. These are the exact steps that you do when writing normal Java programs, but the process
has been streamlined and made transparent to the user. If you’ve ever tried to write a Java pro-
gram that just draws on the screen, you’ll appreciate how much Processing does for you.
The Processing installation includes many sample Processing sketches and you can download
even more samples from the Processing website (http://processing.org/learning/).
Load a few of them and play with them.

You can access the Processing samples by selecting File ➪ Sketchbook ➪ Examples.

Why Use Processing?

Processing enables you to create, run, and share dynamic graphical programs. If you are a pro-
fessional software engineer, Processing may at first seem unnecessary. But many software pro-
fessionals use Processing just because its sketching metaphor and helper functions enable them
to try out ideas fast. Artists and animators find its direct approach to painting on the screen
attractive. And it’s a good tool for beginning programmers due to its simplified environment
and language.
There are many tools somewhat similar to Processing. In the Java development space you have
Java IDEs like the free and awesome Eclipse (www.eclipse.org/). For animation there’s Adobe
Flash (www.adobe.com/products/flash/), which has been getting more powerful as a
general-purpose tool as its ActionScript language has become more standards compliant. For
audio/video processing, there’s Max/MSP/Jitter (www.cycling74.com/products/maxmsp).
This is just a small representative sampling of the tools out there, and all of these tools are better
than Processing in some ways and worse in others.

Cost
Processing is not only free; it’s open source. Anyone can see exactly what Processing is doing and
modify the code to suit his or her needs. Or borrow it. Some of the original RoombaCommSerial
code was taken from the Serial library in Processing. Reading other people’s code is a great way