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

x Introduction
Traditionally, programmers are taught the basics via command line output:
1. TEXT IN → You write your code as text.
2. TEXT OUT → Your code produces text output on the command line.
3. TEXT INTERACTION → Th e user can enter text on the command line to interact with the program.
Th e output “ Hello, World! ” of this example program is an old joke, a programmer’s convention where the text
output of the fi rst program you learn to write in any given language says “ Hello, World! ” It fi rst appeared in a
1974 Bell Laboratories memorandum by Brian Kernighan entitled “ Programming in C: A Tutorial. ”
Th e strength of learning with Processing is its emphasis on a more intuitive and visually responsive
environment, one that is more conducive to artists and designers learning programming.
1.
2.
3.
TEXT IN → You write your code as text.
VISUALS OUT → Your code produces visuals in a window.
MOUSE INTERACTION → Th e user can interact with those visuals via the mouse (and more as
we will see in this book!).
Processing ’s “ Hello, World! ” might look something like this:
Hello, Shapes!
Th ough quite friendly looking, it is nothing spectacular (both of these fi rst programs leave out #3:
interaction), but neither is “ Hello, World! ” However, the focus, learning through immediate visual
feedback, is quite diff erent.
Processing is not the fi rst language to follow this paradigm. In 1967, the Logo programming language was
developed by Daniel G. Bobrow, Wally Feurzeig, and Seymour Papert. With Logo, a programmer writes
instructions to direct a turtle around the screen, producing shapes and designs. John Maeda’s Design By
Numbers (1999) introduced computation to visual designers and artists with a simple, easy to use syntax.