<body>
<div id="target">Target element</div>
<p>
These buttons start additive rotation animations on the
target element with slightly different inital keyframes.<br>
This works in Firefox and Chrome with experimental web platform features enabled.
</p>
<p>
<button id="rotateNone">none -> rotate(180deg)</button><br>
Stacking multiple rotations from none on top of each other
causes matrix interpolation to occur and the motion ends up
getting stuck, going counter clockwise and sometimes
even jumping around.<br>
This behaviour is very non intuitive.
</p>
<p>
<button id="rotate0deg">rotate(0deg) -> rotate(180deg)</button><br>
Using 0deg in the initial keyframe avoids matrix interpolation
and the motion of multiple rotations are stacked intuitively;
never getting stuck, never going counter clockwise.
</p>
<p>
These animations are intuitively the same but behave very
differently under additive composition. This difference
could be avoided if the composition algorithm for Web
Animations performed interpolation before composition
instead of after.<br>
The non-intuitive behaviour comes from the fact that
underlying values can affect interpolation behaviour.
</p>
</body>
#target {
width: 100px;
height: 100px;
border: solid;
margin: 20px;
}
const timing = {
duration: 2000,
fill: 'forwards',
};
rotateNone.addEventListener('click', () => {
target.animate([{
transform: 'none',
composite: 'add',
}, {
transform: 'rotate(180deg)',
composite: 'add',
}], timing);
});
rotate0deg.addEventListener('click', () => {
target.animate([{
transform: 'rotate(0deg)',
composite: 'add',
}, {
transform: 'rotate(180deg)',
composite: 'add',
}], timing);
});
Output
You can jump to the latest bin by adding /latest
to your URL
Keyboard Shortcuts
Shortcut | Action |
---|---|
ctrl + [num] | Toggle nth panel |
ctrl + 0 | Close focused panel |
ctrl + enter | Re-render output. If console visible: run JS in console |
Ctrl + l | Clear the console |
ctrl + / | Toggle comment on selected lines |
ctrl + ] | Indents selected lines |
ctrl + [ | Unindents selected lines |
tab | Code complete & Emmet expand |
ctrl + shift + L | Beautify code in active panel |
ctrl + s | Save & lock current Bin from further changes |
ctrl + shift + s | Open the share options |
ctrl + y | Archive Bin |
Complete list of JS Bin shortcuts |
JS Bin URLs
URL | Action |
---|---|
/ | Show the full rendered output. This content will update in real time as it's updated from the /edit url. |
/edit | Edit the current bin |
/watch | Follow a Code Casting session |
/embed | Create an embeddable version of the bin |
/latest | Load the very latest bin (/latest goes in place of the revision) |
/[username]/last | View the last edited bin for this user |
/[username]/last/edit | Edit the last edited bin for this user |
/[username]/last/watch | Follow the Code Casting session for the latest bin for this user |
/quiet | Remove analytics and edit button from rendered output |
.js | Load only the JavaScript for a bin |
.css | Load only the CSS for a bin |
Except for username prefixed urls, the url may start with http://jsbin.com/abc and the url fragments can be added to the url to view it differently. |