Easing

/**
 * Easing. 
 * 
 * Move the mouse across the screen and the symbol will follow.  
 * Between drawing each frame of the animation, the program
 * calculates the difference between the position of the 
 * symbol and the cursor. If the distance is larger than
 * 1 pixel, the symbol moves part of the distance (0.05) from its
 * current position toward the cursor. 
 */

float x = 0;
float y = 0;
float easing = 0.05f;

void setup() {
    size(640, 360); 
    noStroke();  
}

void draw() { 
    background(51);
  
    float targetX = mouseX;
    float dx = targetX - x;
    x += dx * easing;
  
    float targetY = mouseY;
    float dy = targetY - y;
    y += dy * easing;
  
    ellipse(x, y, 66, 66);
}