javascript - Get distance between two points in canvas

Question

I have canvas drawing tab and want lineWidth to be based on distance between two last mousemove coordinate updates. I will make translation of distance to width myself, I just need to know how to get distance between those points (I already have coordinates of those pointes).

Answer 1

You can do it with pythagoras theorem

If you have two points (x1, y1) and (x2, y2) then you can calculate the difference in x and difference in y, lets call them a and b.

var a = x1 - x2;
var b = y1 - y2;

var c = Math.sqrt( a*a + b*b );

// c is the distance