Processing: Creative Coding and Computational Art

PROCESSING: CREATIVE CODING AND COMPUTATIONAL ART
706
Files
if(key == CODED) {
if (keyCode == UP) {
y--;
} else if (keyCode == DOWN) {
y++;
} else if (keyCode == LEFT) {
x--;
} else if (keyCode == RIGHT) {
x++;
}
}
}
The Files section includes four functions:
•openStream()
•open()
•loadStrings()
•loadBytes()
loadStrings() and loadBytes() allow you to load the contents of a file or URL as a string
array or byte array, respectively. A byte array of a text file will include all the individual
characters converted into their ASCII equivalents. If only a file name is specified as an
argument with either of these functions, the file needs to reside within the sketch’s data
directory. It’s also possible to specify a URL, assuming you use a valid path. Relative paths
should be specified in relation to the data directory in the current sketch directory. For
example, if your file (file.txt) is outside the data directory, in another directory called
docs (also located within the sketch (parent) directory), it can be accessed (using UNIX/OS
X path syntax) as: ../docs/file.txt, or on Windows: ..\docs\file.txt. The double dot
syntax (..) refers to the parent directory; (single dot syntax(.) refers to the current directory).
There is some general information about paths at http://en.wikipedia.org/wiki/
Path_(computing).
The openStream() function provides a simplified way of using Java’s InputStream class.
The InputStream class provides you with more control when inputting data. To learn more
about Java’s InputStream class, check out http://java.sun.com/j2se/1.4.2/docs/api/
java/io/InputStream.html.
Here’s what the Processing reference says about the open() function: “Attempts to open a
file or process using the platform’s shell.” A shell is just an interface to your operating system.
There are GUI (graphical user interface) shells, such as the Finder (OS X) or Windows
Explorer, where you simply click to launch an application. There are also command-line
shells, which is the type of shell the Processing reference is referring to. To communicate
with your system via a command-line shell, you type text-based commands in a terminal
(emulator) program, such as the Terminal application in OS X. (On Windows, you can
access the command shell by selecting the Run command in the Start menu and then