Processing.js
| Language | Javascript |
|---|---|
| Original Creator | John Resig |
| License | MIT |
| Current Release | 1.0.0 / November 18, 2010 |
| Website | http://processingjs.org/ |
Processing.js is a JavaScript port of Processing, a programming language designed to write visualizations, images, and interactive content. It allows web browsers to display animations, visual applications, games and other graphical rich content without the need for a Java Applet or Flash plugin.
Processing.js uses JavaScript to render 2D and 3D content on the HTML canvas element, and is supported by browsers that have implemented this element (Currently the latest versions of Mozilla Firefox, Opera, Safari and Google Chrome).
Use
The Processing.js syntax is almost identical to that of the Processing language, a setup() function is used to define general visualization properties like canvas size, frame rate and other variables, and the draw() function controls the behavior of each frame in the animation.
The Processing.js library can be included in the head section of a web page as a single JavaScript file:
<html>
<head>
<script type="text/javascript" src="processing.js"></script>
</head>
A canvas element is declared inside the body, with a data-processing-sources attribute, specifying the location of an external file holding the Processing code:
<canvas data-processing-sources="example.pde"></canvas>
Any extension can be used in the external file, for example the .pde extension used by the Processing language sketch files.
/* example.pde */
// The statements in the setup() function
// execute once when the program begins
void setup()
{
size(200, 200); // Sets the canvas size to 200 by 200 pixels
stroke(255); // Set line drawing color to monochrome white
frameRate(30); // Set up draw() to be called 30 times per second
}
float y = 100;
// The statements in draw() are executed until the
// program is stopped. The function is called as many
// times per second as the frameRate. If no explicit
// rate is set, this is 45 times per second.
void draw()
{
background(0); // Set the background to monochrome black
y = y - 1;
if (y < 0) { y = height; }
line(0, y, width, y); // draw a horizontal line at height y
}
References
- Glassner, Andrew (August 9, 2010), Processing for Visual Artists: How to Create Expressive Images and Interactive Art (1st ed.), A K Peters/CRC Press, p. 955, ISBN 1568817169
- Reas, Casey; Fry, Ben (June 17, 2010), Getting Started with Processing (1st ed.), Make, p. 208, ISBN 144937980X
- Noble, Joshua (July 21, 2009), Programming Interactivity: A Designer's Guide to Processing, Arduino, and Openframeworks (1st ed.), O'Reilly Media, p. 736, ISBN 0596154143
- Terzidis, Kostas (May 11, 2009), Algorithms for Visual Design Using the Processing Language (1st ed.), Wiley, p. 384, ISBN 0470375485
- Reas, Casey; Fry, Ben; Maeda, John (September 30, 2007), Processing: A Programming Handbook for Visual Designers and Artists (1st ed.), The MIT Press, p. 736, ISBN 0262182629
- Fry, Ben (January 11, 2008), Visualizing Data (1st ed.), O'Reilly Media, p. 382, ISBN 0596514557
- Greenberg, Ira (May 28, 2007), Processing: Creative Coding and Computational Art (Foundation) (1st ed.), friends of ED, p. 840, ISBN 159059617X
- Shiffman, Daniel (August 19, 2008), Learning Processing: A Beginner's Guide to Programming Images, Animation, and Interaction (1st ed.), Morgan Kaufmann, p. 450, ISBN 0123736021