Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
// Modified from http://mattsnider.com/cross-browser-and-legacy-supported-requestframeanimation/
// LICENSE: MIT: http://mattsnider.com/projects/license/
(function(w) {
"use strict";
// most browsers have an implementation
w.requestAnimationFrame = w.requestAnimationFrame ||
w.mozRequestAnimationFrame || w.webkitRequestAnimationFrame ||
w.msRequestAnimationFrame;
w.cancelAnimationFrame = w.cancelAnimationFrame ||
w.mozCancelAnimationFrame || w.webkitCancelAnimationFrame ||
w.msCancelAnimationFrame;
// polyfill, when necessary
if (!w.requestAnimationFrame) {
var aAnimQueue = [],
aProcessing = [],
iRequestId = 0,
iIntervalId;
// create a mock requestAnimationFrame function
w.requestAnimationFrame = function(callback) {
aAnimQueue.push([++iRequestId, callback]);
if (!iIntervalId) {
iIntervalId = setInterval(function() {
if (aAnimQueue.length) {
var time = +new Date();
// Process all of the currently outstanding frame
// requests, but none that get added during the
// processing.
// Swap the arrays so we don't have to create a new
// array every frame.
var temp = aProcessing;
aProcessing = aAnimQueue;
aAnimQueue = temp;
while (aProcessing.length) {
aProcessing.shift()[1](time);
}
} else {
// don't continue the interval, if unnecessary
clearInterval(iIntervalId);
iIntervalId = undefined;
}
}, 1000 / 50); // estimating support for 50 frames per second
}
return iRequestId;
};
// create a mock cancelAnimationFrame function
w.cancelAnimationFrame = function(requestId) {
// find the request ID and remove it
var i, j;
for (i = 0, j = aAnimQueue.length; i < j; i += 1) {
if (aAnimQueue[i][0] === requestId) {
aAnimQueue.splice(i, 1);
return;
}
}
// If it's not in the queue, it may be in the set we're currently
// processing (if cancelAnimationFrame is called from within a
// requestAnimationFrame callback).
for (i = 0, j = aProcessing.length; i < j; i += 1) {
if (aProcessing[i][0] === requestId) {
aProcessing.splice(i, 1);
return;
}
}
};
}
})(window);
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.