Returns the current position of this tween, a float number usually between 0 to 1.
position() is the result of the easing function with time() as its input.
Example
import megamu.shapetween.*;
Tween ani;
void setup(){
ani = new Tween(this, 2);
}
void draw(){
background(255);
ellipse(ani.time()*width, ani.position()*height, 4, 4);
}