framer-motion
Version:
A simple and powerful JavaScript animation library
42 lines (39 loc) • 1.57 kB
JavaScript
import { px } from '../../value/types/numbers/units.mjs';
function pixelsToPercent(pixels, axis) {
if (axis.max === axis.min)
return 0;
return (pixels / (axis.max - axis.min)) * 100;
}
/**
* We always correct borderRadius as a percentage rather than pixels to reduce paints.
* For example, if you are projecting a box that is 100px wide with a 10px borderRadius
* into a box that is 200px wide with a 20px borderRadius, that is actually a 10%
* borderRadius in both states. If we animate between the two in pixels that will trigger
* a paint each time. If we animate between the two in percentage we'll avoid a paint.
*/
const correctBorderRadius = {
correct: (latest, node) => {
if (!node.target)
return latest;
/**
* If latest is a string, if it's a percentage we can return immediately as it's
* going to be stretched appropriately. Otherwise, if it's a pixel, convert it to a number.
*/
if (typeof latest === "string") {
if (px.test(latest)) {
latest = parseFloat(latest);
}
else {
return latest;
}
}
/**
* If latest is a number, it's a pixel value. We use the current viewportBox to calculate that
* pixel value as a percentage of each axis
*/
const x = pixelsToPercent(latest, node.target.x);
const y = pixelsToPercent(latest, node.target.y);
return `${x}% ${y}%`;
},
};
export { correctBorderRadius, pixelsToPercent };