/* built with Studio Sketchpad: 
 *   https://sketchpad.cc
 * 
 * observe the evolution of this sketch: 
 *   https://studio.sketchpad.cc/sp/pad/view/ro.xyu1E6MiImy/rev.8
 * 
 * authors: 
 *   GoToLoop

 * license (unless otherwise specified): 
 *   creative commons attribution-share alike 3.0 license.
 *   https://creativecommons.org/licenses/by-sa/3.0/ 
 */ 



/**
 * Easing Box (v2.2)
 * Author: MsKelly (2016-Oct-04)
 * Mod: GoToLoop
 *
 * forum.Processing.org/two/discussion/18404/
 * processing-code-doesn-t-work-in-p5#Item_5
 *
 * studio.SketchPad.cc/sp/pad/view/ro.9XkJm3bjTAxB2/latest
 */

static final float EASING = .05, LIMIT = .1;
static final int RAD = 15, EDGE = 50;
static final int INNER = EDGE + RAD;

float mx = INNER, my = INNER;
int iw, ih, ew, eh;

void setup() {
  size(400, 500);

  ellipseMode(RADIUS);
  rectMode(CORNERS);

  noStroke();
  background(0);

  iw = width  - INNER;
  ih = height - INNER;

  ew = width  - EDGE;
  eh = height - EDGE;
}

void draw() {
  final float dx = mouseX - mx, dy = mouseY - my;

  if (abs(dx) > LIMIT)  mx = constrain(mx + dx*EASING, INNER, iw);
  if (abs(dy) > LIMIT)  my = constrain(my + dy*EASING, INNER, ih);

  fill(196, 239, 234);
  rect(EDGE, EDGE, ew, eh);

  fill(146, 140, 211);
  ellipse(mx, my, RAD, RAD);
}