Create svg arcs between two points

Question

I want to connect two SVG points (e.g. the centers of two circles) using arcs. If there is only one connection, the line () will be straight. I

Answer 1

Here is a solution that uses arcs, as asked for, rather than quadratic curves.

// Internal function
function connectInternal(x1,y1,x2,y2,con){
 var dx=x2-x1
 var dy=y2-y1
 var dist=Math.sqrt(dx*dx+dy*dy)
 if(dist==0 || con==0){
  return "M"+x1+","+y1+"L"+x2+","+y2
 }
 var xRadius=dist*0.75
 var yRadius=dist*0.3*(con*0.75)
 var normdx=dx/dist
 if(normdx<-1)normdx=-1
 if(normdx>1)normdx=1
 var angle=Math.acos(normdx)*180/Math.PI
 if(x1>x2){
  angle=-angle
 }
 return "M"+x1+","+y1+"A"+xRadius+","+yRadius+","+
   angle+",00"+x2+","+y2+
   "M"+x1+","+y1+"A"+xRadius+","+yRadius+","+
   angle+",01"+x2+","+y2
}

// Returns an SVG path that represents
// "n" connections between two points.
function connect(x1,y1,x2,y2,n){
 var ret=""
 var con=n
 if(con%2==1){
  ret+=connectInternal(x1,y1,x2,y2,con)
  con-=1
 }
 for(var i=2;i<=con;i+=2){
  ret+=connectInternal(x1,y1,x2,y2,i)
 }
 return ret
}