piskel/js/rendering/DrawingLoop.js

61 lines
1.7 KiB
JavaScript

(function () {
var ns = $.namespace("pskl.rendering");
ns.DrawingLoop = function () {
this.requestAnimationFrame = this.getRequestAnimationFrameShim_();
this.isRunning = false;
this.previousTime = 0;
this.callbacks = [];
};
ns.DrawingLoop.prototype.addCallback = function (callback, scope, args) {
var callbackObj = {
fn : callback,
scope : scope,
args : args
};
this.callbacks.push(callbackObj);
return callbackObj;
};
ns.DrawingLoop.prototype.removeCallback = function (callbackObj) {
var index = this.callbacks.indexOf(callbackObj);
if (index != -1) {
this.callbacks.splice(index, 1);
}
};
ns.DrawingLoop.prototype.start = function () {
this.isRunning = true;
this.loop_();
};
ns.DrawingLoop.prototype.loop_ = function () {
var currentTime = Date.now();
var delta = currentTime - this.previousTime;
this.executeCallbacks_(delta);
this.previousTime = currentTime;
this.requestAnimationFrame.call(window, this.loop_.bind(this));
};
ns.DrawingLoop.prototype.executeCallbacks_ = function (deltaTime) {
for (var i = 0 ; i < this.callbacks.length ; i++) {
var cb = this.callbacks[i];
cb.fn.call(cb.scope, deltaTime, cb.args);
}
};
ns.DrawingLoop.prototype.stop = function () {
this.isRunning = false;
};
ns.DrawingLoop.prototype.getRequestAnimationFrameShim_ = function () {
var requestAnimationFrame = window.requestAnimationFrame ||
window.mozRequestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.msRequestAnimationFrame ||
function (callback) { window.setTimeout(callback, 1000/60); };
return requestAnimationFrame;
};
})();