Circle collision in JavaScript
Your check should be if (a > Math.sqrt((x*x) + (y*y)))
http://cgp.wikidot.com/circle-to-circle-collision-detection
So the complete code is
function collision(p1x, p1y, r1, p2x, p2y, r2) {
var a;
var x;
var y;
a = r1 + r2;
x = p1x - p2x;
y = p1y - p2y;
if (a > Math.sqrt((x * x) + (y * y))) {
return true;
} else {
return false;
}
}
var collision = collision(5, 500, 10, 1000, 1500, 1500);
console.log(collision);and for a less computational implementation (using ES7 syntax for the snippet) use
const checkCollision = (p1x, p1y, r1, p2x, p2y, r2) => ((r1 + r2) ** 2 > (p1x - p2x) ** 2 + (p1y - p2y) ** 2)
var collision = checkCollision(5, 500, 10, 1000, 1500, 1500);
console.log(collision);as Darek Rossman shows in his answer.
In your if statement, try this instead:
if ( a * a > (x * x + y * y) ) {
...
} else {
...
}