Learning Processing: A Beginner's Guide to Programming Images ...

424 Learning Processing
“ SketchName.java. ” Th is is your “ translated ” code, only translation is somewhat of a misnomer since very
little changes. Let’s look at an example:
// Randomly Growing Square
float w = 30.0; // Variable to keep track of size of rect
void setup() {
size(200, 200);
}
void draw() {
background(100);
rectMode(CENTER);
fill(255);
noStroke();
rect(mouseX,mouseY,w,w); // Draw a rect at mouse location
w + = random( – 1,1); // Randomly adjust size variable
}
Exporting the sketch, we can open up the Java fi le and look at the Java source.
// Randomly Growing Square with Java Stuff
import processing.core.*;
import java.applet.*;
import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
import java.text.*;
import java.util.*;
import java.util.zip.*;
public class JavaExample extends PApplet {
float w = 30.0f; // Variable to keep track of size of rect
public void setup() {
size(200, 200);
}
What we are used to seeing, our
regular old Processing code.
The translated Java code has
some new stuff at the top, but
everything else stays the same.
public void draw() {
background(100);
rectMode(CENTER);
fill(255);
noStroke();
rect(mouseX,mouseY,w,w); // draw a rect at mouse location
w + = random( – 1,1); // randomly adjust size variable
}
}
It is clear that little has changed, rather, some code has been added before and after the usual setup( ) and
draw( ) stuff .
• Import Statements —At the top, there are a set of import statements allowing access to certain
libraries. We have seen this before when using Processing libraries. If we were using regular Java