Processing: Creative Coding and Computational Art

PROCESSING: CREATIVE CODING AND COMPUTATIONAL ART
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Input
This is another large section in the API, generally involved in receiving or inputting data.
Some of these processes are relatively low level, like reading bytes. However, Processing,
as you’ve probably come to expect by now, encapsulates and simplifies these processes.
The Input section includes 22 functions and 9 system variables, divided into five categories.
The categories are as follows:
Mouse
Mouse
Keyboard
Files
Web
Time & Date
The Mouse section includes six properties and five functions, used to evaluate when,
where, and how mouse input is received by your running sketch. Variables such as mouseX
and mousePressed provide live information about the mouse state; mouseX provides the
current x position of the mouse and mousePressed returns true or false depending if the
mouse button is pressed. Often, you can use this data creatively—for example, in a drawing
program that colors pixels as the mouse moves over them.
The mouse functions, such as mouseMoved() or mouseDragged(), put code within separate
function blocks (between the curly braces), allowing other functions or commands to be
called when the mouse motion event is detected. Following is a mouseMoved() example
that illustrates some of the interesting things you can do via mouse detection (see
Figure A-9). There are a bunch of significant concepts within this example, and in spite of
it being a bit dense, the sketch is a good base for other experiments. When the sketch
loads, move your mouse over the rectangle.
/*
Box Springs
Ira Greenberg, November 13, 2005
revised October 11, 2006
move mouse over white rectangle
*/
// you can change block count
int blocks = 40;
float margin = 50;
float boxHeight = 75;