Math extra

math.js

// Point position on a line
// (see also https://github.com/ayamflow/point-in-line)
pointInLine: function(p1, p2, t)
  return {
    p1.x + t * (p2.x - p1.x)
    p1.y + t * (p2.y - p1.y)
  };
}

clamp: function(value, min, max) {
  return Math.max(min, Math.min(max, value));
}

norm: function(value, min, max) {
 return (value - min) / (max - min);
}

lerp: function(ratio, start, end) {
	return start + (end - start) * ratio;
}

map: function(value, sourceMin, sourceMax, destMin, destMax) {
	return lerp(norm(value, sourceMin, sourceMax), destMin, destMax);
}