bouncing-ball/index-javascript.html at main · evoluteur/bouncing-ball · GitHub

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<!doctype html>
<html lang="en">
  <head>
    <script
      async
      src="https://www.googletagmanager.com/gtag/js?id=G-063933E3C2"
    ></script>
    <script>
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    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Bouncing ball in JavaScript</title>
    <link
      rel="canonical"
      href="https://evoluteur.github.io/bouncing-ball/index-javascript.html"
    />
    <meta name="author" content="Olivier Giulieri" />
    <meta name="robots" content="index, follow" />
    <meta
      name="description"
      content="Bouncing ball animation demo in JavaScript using setInterval and DOM positioning. Minimal example showing how to animate elements with JavaScript."
    />
    <meta
      name="keywords"
      content="bouncing, ball, javascript, animated, animation, setInterval, DOM, transition, fullscreen, sample, code"
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    <meta
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    <meta property="og:title" content="Bouncing ball in JavaScript" />
    <meta
      property="og:description"
      content="Bouncing ball animation demo in JavaScript using setInterval and DOM positioning. Minimal example showing how to animate elements with JavaScript."
    />
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      content="Bouncing ball animation demo in JavaScript using setInterval and DOM positioning."
    />
    <link rel="icon" type="image/png" href="favicon.png" />
    <link
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      href="https://fonts.googleapis.com/css?family=Overpass"
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    <link rel="stylesheet" href="bball.css" />
    <script>
      let x = 0,
        y = 0,
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        maxY = window.innerHeight - 50;
        if (y > maxY) {
          y = maxY;
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      }

      function bounce() {
        if (x > maxX || x < 0) {
          leftRight = -leftRight;
        }
        if (y > maxY || y < 0) {
          upDown = -upDown;
        }
        x = x + 10 * leftRight;
        y = y + 10 * upDown;
        ball.style.top = y + "px";
        ball.style.left = x + "px";
      }

      function startBouncing() {
        setDim();
        setInterval(bounce, 12);
      }
    </script>
  </head>

  <body onresize="setDim()" onload="startBouncing()">
    <div class="content">
      <h1>Bouncing ball in JavaScript <a href="./index.html">or CSS</a></h1>

      <p>Javascript animation for a bouncing ball.</p>

      <p>
        Cast in shadow, falls,<br />Strikes the floor and leaps again,<br />Darkness
        on the bounce.
      </p>
      <p>
        Code:
        <a href="https://github.com/evoluteur/bouncing-ball"
          >evoluteur/bouncing-ball</a
        >
        at GitHub.
      </p>

      <div id="ball"></div>

      <p>
        <br />&#169; 2020–2026
        <a href="https://evoluteur.github.io/">Olivier Giulieri</a>
      </p>
    </div>
  </body>
</html>