Animation looping utility for the browser
Flywheel is a lightweight tool to make working with HTML5's requestAnimationFrame simpler.
Flywheel takes two arguments:
A callback to loop over. It passes the amount of time passed since the last frame to the callback.
A DOM element, which acts identically to the requestAnimationFrame second parameter.
After setup, it returns an object that can be used to manipulate the loop. By default, the loop is not running; to start it, use the methods from the next section.
var element = documentgetElementsByTagName"canvas"0/* do animation work here */var fw = flywheelanimation_loop element
// start and stopfwstartfwstop// toggle loop on and offfwtogglefwtoggle
To change a callback:
/* do alternative animation work here */
To change an element:
fwelement = documentgetElementById"my_other_canvas"
When a page loses focus or the loop is paused, the gap between frames can be large enough to cause problems in games (especially where acceleration or collision detection is involved). To combat this, flywheel limits the
time_delta value passed to the callback ( by default, to 50ms; equivilent to ~20fps ).
To change the cap:
fwframerate_cap = 40
// step forwards a frame (assuming a time delta of 16ms; equivilent to ~60fps)fwstep// step forwards with a custom time delta.fwstep30
This software is available under the MIT license.