I am creating animated calligraphy using the stroke-dashoffset technique, applying the stroke as an animated mask on top of an SVG. This works on most browsers, but I would like to apply the same mask on top of a PNG instead. That way, even if the browser has trouble with both SVG and mask (IE...), at least it will just display the PNG as-is.
Here is a codepen of the working calligraphy with pure SVG: https://codepen.io/benviatte/pen/PMzmYB
Here is the codepen of the non-working calligraphy where I put an image instead of the base SVG. It just displays blank, unless I remove the "mask-image" property, in which case it doesn't animate: https://codepen.io/benviatte/pen/eqzWzJ
Finally, here is the code of the PNG version that just displays blank: HTML:
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 354.33071 248.03149">
<mask id="mask" maskUnits="userSpaceOnUse">
<path d="M 92.81613,118.88531 C 92.79077,113.54067 89.77774,108.7899 89.336626,103.42689 96.06007,89.146492 85.818314,62.350762 62.06357,80.661632 c -5.787226,7.87329 -12.023557,16.43904 -12.784729,26.500038 -0.404099,5.34115 3.084547,9.85663 7.361464,12.76814 9.170344,6.24271 20.057653,10.0779 27.888503,18.14154 4.373535,4.50356 2.810446,11.25662 2.004789,16.78827 -1.093846,7.51033 -10.89645,19.36241 -18.314927,21.84098 -9.433311,3.81749 -18.936726,-10.31651 -25.709437,-30.06406" />
</mask>
</svg>
<img src="http://thehermitcrab.org/imgs/S2.png"/>
CSS:
mask path {
fill: none;
stroke: white;
stroke-width: 22;
stroke-dasharray: 237 237;
stroke-dashoffset: 237;
animation: brush 1s cubic-bezier(.6,.3,.3,.9);
animation-fill-mode: forwards;
}
@keyframes brush {
0% { stroke-dashoffset: 237; }
20% { stroke-dashoffset: 237; }
80% { stroke-dashoffset: 0; }
100% { stroke-dashoffset: 0; }
}
img, svg{
width: 300px;
position: absolute;
top: 0;
left: 0;
}
img {
-webkit-mask-image: url(#mask);
mask-image: url(#mask);
}
Thank you so much!!!