How can I calculate the rotation angle for a div element?

Question

I am trying to make a div face towards an x and y position on the screen.

For example, if I have a div at coordinates 50, 0 , and I want it to face 0, 0 , then I would need to rotate the div -90 degrees (or left).

Is there some sort of equation or function I can use to get the degrees that the div should rotate, depending on the two sets of coordinates?

Answer 1

Using JavaScript:

Math.atan2(dx, dy) * 180 / Math.PI

Where

dx = p2.x - p1.x 
dy = p2.y - p1.y

Answer 2

You can use the rotate method to achieve the rotation of an element.

<!DOCTYPE html>
<html>
<head>
<style>
div {
    width: 300px;
    height: 100px;
    background-color: green;
    border: 1px solid black;
}

div#myDiv {
    -ms-transform: rotate(-90deg); /* IE 9 */
    -webkit-transform: rotate(-90deg); /* Safari */
    transform: rotate(-90deg); /* Standard syntax */
}
</style>
</head>
<body>

<h1>The rotate() Method</h1>
<p>The rotate() method rotates an element clockwise or counter-clockwise.</p>

<div>
This a normal div element.
</div>

<div id="myDiv">
This div element is rotated clockwise -90 degrees.
</div>

</body>
</html>

DEMO

How can I calculate the rotation angle for a div element?

Question

2 answers

solution1
2 ACCPTED 2018-10-02 06:27:45

solution2
0 2018-10-02 06:18:31

How can I calculate the rotation angle for a div element?

Question

2 answers

solution1 2 ACCPTED 2018-10-02 06:27:45

solution2 0 2018-10-02 06:18:31

solution1
2 ACCPTED 2018-10-02 06:27:45

solution2
0 2018-10-02 06:18:31