PImage words;
float bx;
float by;
int bs;
boolean bover = false;
boolean locked = false;
float bdifx = 0.0; 
float bdify = 0.0; 


void setup() 
{
  size(600, 600);
 words = loadImage("words.png");
  rectMode(CENTER_RADIUS);  
}

void draw() 
{
  background(255);
  image(words, 0, 0);
   stroke(0);
  draw_circle(200, 200,350); 
  draw_circle(400, 200,350); 
  draw_circle(300, 400,350); 
  // Test if the cursor is over the box 
  
}

void mousePressed() {
  if(bover) { 
    locked = true; 
    fill(255, 255, 255);
  } else {
    locked = false;
  }
  bdifx = mouseX-bx; 
  bdify = mouseY-by; 

}

void mouseDragged() {
  if(locked) {
    bx = mouseX-bdifx; 
    by = mouseY-bdify; 
  }
}

void mouseReleased() {
  locked = false;
}

void draw_circle(float bx, float by, int bs){
  if (mouseX > bx-bs/2 && mouseX < bx+bs/2 && 
      mouseY > by-bs/2 && mouseY < by+bs/2) {
    bover = true;  
    if(!locked) { 
      stroke(0); 
      fill(220, 50);
    }    
  } else {
    stroke(0);
    fill(255);
    bover = false;
  }
  // Draw the box
  ellipse(bx, by, bs, bs);
}