HTML and CSS Reference
In-Depth Information
To start building your dependencies, or the files your engine is dependent on, navigate to
the assets folder. Inside create a file called animation.js using Paul Irish's
requestAn-
imationFrame()
shown in the following listing (
http://mng.bz/h9v9
).
Listing 9.3. animation.jsâRequesting animation and intervals
window
.
requestAnimFrame
= (
function
() {
return
window
.
requestAnimationFrame
||
window
.
webkitRequestAnimationFrame
||
window
.
mozRequestAnimationFrame
||
window
.
oRequestAnimationFrame
||
window
.
msRequestAnimationFrame
||
function
(
callback
) {
window
.
setTimeout
(
callback
,
1000
/
60
);
};
})();
John Resig's simple JavaScript inheritance
Because your engine requires you to create objects that can be modified, tweaked, and in-
herited on the fly, you need an extendable class. The problem is that classes usually require
a robust library like prototype.js because JavaScript doesn't natively support them. To keep
your engine's file size and dependencies limited, we're using a slightly modified version of
John Resig's Simple JavaScript Inheritance script (
http://ejohn.org/blog/simple-javascript-
inheritance/
)
. Insert a modified version of John Resig's script from the following listing
into a file called classes.js in the assets folder.
