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

334 Learning Processing
Example 18-4: Loading and saving data to text fi le
// An array of Bubble objects
Bubble[] bubbles;
void setup() {
size(200,200);
smooth();
// Load text file as a string
String[] data = loadStrings(" data.txt " );
Bubble data is loaded in setup().
// Make as many objects as lines in the text file
bubbles = new Bubble[data.length];
// Convert values to floats and pass into Bubble constructor
for (int i = 0; i < bubbles.length; i + + ) {
float[] values = float(split(data[i], " , " ));
bubbles[i] = new Bubble(values[0],values[1],values[2]);
}
}
void draw() {
background(255);
// Display and move all bubbles
for (int i = 0; i < bubbles.length; i + +) {
bubbles[i].display();
bubbles[i].drift();
// Change bubbles if mouse rolls over
if (bubbles[i].rollover(mouseX,mouseY)) {
bubbles[i].change();
}
}
}
// Save new Bubble data when mouse is Pressed
void mousePressed() {
saveData();
}
void saveData() {
// For each Bubble make one String to be saved
String[] data = new String[bubbles.length];
for (int i = 0; i < bubbles.length; i + +) {
// Concatenate bubble variables
data[i] = bubbles[i].r + " , " + bubbles[i].g + " , " + bubbles[i].diameter;
}
// Save to File
saveStrings( " data/data.txt ",data);
}
// A Bubble class
class Bubble {
float x,y;
float diameter;
float speed;
float r,g;
The same fi le is overwritten by
adding the “data” folder path
to saveStrings() as shown in
Figure 18.8.
Bubble data is saved in
mousePressed().
Bubble(float r_,float g_, float diameter_) {
x = random(width);
y = height;
r = r_;
g = g_; fi g 18.8 The new data fi le after save strings ( )