How can I generate random points on a circles circumference in javascript

问题

I am trying to write a function that will randomly return an (x,y) co-ordinates around a given circumference so if I have a point that's at (0,0) (being the center of the div) how can I write a function that randomly places other entities that appear among the outer edge of a circle.

All I need is the equation i know it has something to do with getting the distance from the center to the circumference edge just no idea how to calculate it and randomize it so it looks good.

回答1:

Just get a random angle:

var angle = Math.random()*Math.PI*2;

Then

x = Math.cos(angle)*radius;
y = Math.sin(angle)*radius;

Done.

来源：https://stackoverflow.com/questions/9879258/how-can-i-generate-random-points-on-a-circles-circumference-in-javascript