Reputation: 503
I'd like to animate the "mask-position" property of a CSS mask image. The mask-image itself is a simple gradient, and my intended behavior is that by changing the value of the mask position, I can make the background object fade in from left to right. However, is it possible to animate this property? If not, is there a workaraound?
.header-image figure {
mask-image: url("http://thehermitcrab.org/wp-content/themes/the-hermit-theme/images/gradient-mask-straight.png");
animation: clip-fade 3s;
}
@keyframes clip-fade {
0% {mask-position: 100% 0%;}
100% {mask-position: 0% 0%;}
}
The HTML:
<div class="header-image">
<figure>
<img src="https://thehermitcrab.org/wp-content/themes/the-hermit-theme/images/footer/crab-footer-chalk-logo.png"/>
</figure>
</div>
Upvotes: 13
Views: 23404
Reputation: 272648
Not sure what kind of animation you want to perform but since it's a simple gradient no need to consider an image. Simply define the gradient and then you must define the size in order to correctly animate it.
Here is a basic example
.header-image figure {
-webkit-mask-image: linear-gradient(90deg, #0000, #fff, #0000);
mask-image: linear-gradient(90deg, #0000, #fff, #0000);
-webkit-mask-size: 300% 100%;
mask-size: 300% 100%;
animation: clip-fade 3s infinite alternate;
}
img {
max-width: 100%;
}
@keyframes clip-fade {
100% {
-webkit-mask-position: right;
mask-position: right;
}
}
body {
background: red;
}
<div class="header-image">
<figure>
<img src="https://i.sstatic.net/lkGW7.png" />
</figure>
</div>
Gradient used in mask works the same way as used in background so here is a related question to get more details about how to deal with the calculation: Using percentage values with background-position on a linear-gradient
Upvotes: 21