17 lines
742 B
JavaScript
17 lines
742 B
JavaScript
|
// Get angle on circle from mouse position
|
||
|
|
function getAngleOnCircleFromOffsetMouse(evt) {
|
||
|
|
const x = (evt.pageX - element.offset().left);
|
||
|
|
const y = (evt.pageY - element.offset().top);
|
||
|
|
|
||
|
|
// https://math.stackexchange.com/a/127615
|
||
|
|
const center = { x: width / 2, y: width / 2 };
|
||
|
|
const xCenter = (x - center.x);
|
||
|
|
const yCenter = (y - center.y);
|
||
|
|
const circlePoint = {
|
||
|
|
x: center.x + radius * (xCenter / Math.sqrt(xCenter * xCenter + yCenter * yCenter)),
|
||
|
|
y: center.y + radius * (yCenter / Math.sqrt(xCenter * xCenter + yCenter * yCenter)),
|
||
|
|
};
|
||
|
|
|
||
|
|
const angle = Math.atan2(circlePoint.y - center.y, circlePoint.x - center.x) + Math.PI / 2;
|
||
|
|
return angle < 0 ? Math.PI * 2 - Math.abs(angle) : angle;
|
||
|
|
}
|