If i remove the mousePressed condition, the arc and ellipse make 1 360 degree rotation.  With the mousePresed condition, the arc and the ellipse travel much further than 360 degrees, I cannot figure out why that would be.

I am new to processing and programming in general, so point out any indelicacies in the code.

float arcStop;
float theta;
float x,y;

void setup(){
 size(400,400);

 
}

void draw(){
 background(50);
 noFill();
 smooth();
 
 arc(200,200,100,100,0,arcStop);
 ellipse(x,y,10,10);
 
 if(mousePressed){
 arcStop=map(mouseX,0,width,0,TWO_PI);
 theta=TWO_PI+arcStop;
 x=50*cos(theta)+200;
 y=50*sin(theta)+200;
 }
}