funfriend/src/ease.cr

module Funfriend::Ease
  extend self

  include Math

  def inSine(x)
    1 - cos(x * (PI * 0.5))
  end
  def outSine(x)
    sin(x * (PI * 0.5))
  end
  def inOutSine(x)
    0.5 - 0.5 * cos(x * PI)
  end
end