git.r.bdr.sh - rbdr/forum/blob - src/animations/blink.js

   1 import { sineOut } from 'svelte/easing';
   2
   3 export const blink = function blink(node, params) {
   4
   5   const originalWidth = parseFloat(getComputedStyle(node).width);
   6   const originalHeight = parseFloat(getComputedStyle(node).height);
   7
   8   return {
   9     delay: params.delay || 0,
  10     duration: params.duration || 400,
  11     easing: params.easing || sineOut,
  12     css: (t, u) => {
  13
  14       const halfWidth = originalWidth / 2;
  15       const halfHeight = originalHeight / 2;
  16       const height = Math.round(t <= 0.2 ? (originalHeight * t) / 0.2 : originalHeight);
  17       const marginY = Math.round(t <= 0.2 ? halfHeight * (1 - t / 0.2) : 0);
  18       const width = Math.round(t > 0.2 ? ((t - 0.2) / 0.8) * originalWidth : 0);
  19       const marginX = Math.round(t > 0.2 ? (1 - (t - 0.2) / 0.8) * halfWidth : halfWidth);
  20
  21       return `width: ${width}px; height: ${height}px; margin: ${marginY}px ${marginX}px`;
  22     }
  23   };
  24 };