en.javascript.info/7-animation/3-js-animation/1-animate-ball/solution.md
Ilya Kantor db32cd032c minor
2019-05-22 01:14:22 +03:00

19 lines
701 B
Markdown

To bounce we can use CSS property `top` and `position:absolute` for the ball inside the field with `position:relative`.
The bottom coordinate of the field is `field.clientHeight`. The CSS `top` property refers to the upper edge of the ball. So it should go from `0` till `field.clientHeight - ball.clientHeight`, that's the final lowest position of the upper edge of the ball.
To to get the "bouncing" effect we can use the timing function `bounce` in `easeOut` mode.
Here's the final code for the animation:
```js
let to = field.clientHeight - ball.clientHeight;
animate({
duration: 2000,
timing: makeEaseOut(bounce),
draw(progress) {
ball.style.top = to * progress + 'px'
}
});
```