Introduction
Processing is a language and development environment oriented toward interaction design . In the course Media Processing in Processing (MPP) , processing is one of the main instruments used to introduce some fundamentals insound and image processing. Processing is an extension of Java that supports many Java structures with a simplified syntax.
Processing can be used in three
-
Basic
Sequence of commands for simple drawing by graphic primitives. --applet without nose size(256,256); background(0);stroke(255); ellipseMode(CORNER);ellipse(72,100,110,130); triangle(88,100,168,100,128,50);stroke(140); strokeWeight(4);line(96,150,112,150); line(150,150,166,150);line(120,200,136,200);
-
Intermediate
Procedural programming --applet with nose void setup() { size(256,256);background(0); }void draw() {stroke(255); strokeWeight(1);ellipseMode(CORNER); ellipse(72,100,110,130);triangle(88,100,168,100,128,50); stroke(140);beginShape(TRIANGLES); vertex(114, 180);vertex(mouseX, mouseY); vertex(140, 180);endShape(); strokeWeight(4);line(96,150,112,150); line(150,150,166,150);line(120,200,136,200); }
-
Complex
Object-Oriented Programming (Java) --applet with colored nose Puppet pinocchio;void setup() { size(256,256);background(0); color tempcolor = color(255,0,0);pinocchio = new Puppet(tempcolor); }void draw() { background(0);pinocchio.draw(); }class Puppet { color colore;Puppet(color c_) { colore = c_;} void draw () {stroke(255); strokeWeight(1);ellipseMode(CORNER); ellipse(72,100,110,130);stroke(colore); beginShape(TRIANGLES);vertex(114, 180); vertex(mouseX, mouseY);vertex(140, 180); endShape();strokeWeight(4); line(96,150,112,150);line(150,150,166,150); }}
Programming modes
The Processing programs can be converted into Java applets.
In order to do that, one just goes to the
File menu and chooses
Export . As a
result, five files will be created and put in an
applet
folder:
-
Index.html
html code to visualize the applet -
Filename.jar
the compiled applet, including all data (images, sounds, etc.) -
Filename.pde
the Processing source code -
Filename.java
the Java code embedding the Processing source code -
Loading.gif
an image to be displayed while the applet is being loaded.
Data types
Variables
A variable is a
pointer to a memory location, and it can refer either toprimitive values (
int
,
float
, ecc.)
or to objects and arrays (tables of primitive-typeelements).
The operation of
assignment
b = a
produces
- The copy of the content of
a
intob
, if the variables refer to primitive types. - The creation of a new reference (pointer) to the same object or array, if the variables refer toobjects or arrays.