float dx, dy, delta,angle;
float centerX,centerY;





void setup(){
  size(400,400);
  background(255);
  centerX=200;
  centerY=200;
}

void draw(){
  if (mousePressed){
    if(keyPressed){
      if(key=='1'){
        stroke(255,0,0);
        rect(mouseX,mouseY,dx,dy);
        line(mouseX,mouseY,centerX,centerY);
      }
      if(key=='2'){
        stroke(0,255,0);
        rect(mouseX,mouseY,dx,dy);
        line(mouseX,mouseY,centerX+50,centerY+50);  
      }
      if(key=='3'){
        stroke(0,0,255);
        rect(mouseX,mouseY,dx,dy);
        line(mouseX,mouseY,centerX+100,centerY+100);  
      }



      /////////////////////////////
      dx = mouseX - pmouseX;
      dy = mouseY - pmouseY;
      delta = sqrt(dx*dx + dy*dy);

      dx = mouseX - pmouseX;
      dy = mouseY - pmouseY;
      angle = atan2(dy,dx)-PI/2;
      /////////////////////////////

    }

  }
}