A simple Coffee Script LFO to run on the browser. Useful for animations and modulations. # - performance.now() will return browser microsecond precision when possible # - if you wish to use outside of the browser just use some other timing source instead of "performance.now()" # - parameter "speed" could use a more comprehensive time unit, "ms" …

Simple coffee script LFO

#
# If you wish to have a landscape "8" movement, like the "infinity sign" you should use something like:
#   lfo   = new LFO 1
#   lfo_y = new LFO 0.5
#
# Then if you wish to make it slower, multiply both by same value
#
#   lfo   = new LFO 1   * 2
#   lfo_y = new LFO 0.5 * 2
#

performance = performance || {};
performance.now = 
  performance.now       ||
  performance.mozNow    ||
  performance.msNow     ||
  performance.oNow      ||
  performance.webkitNow ||
  -> return Date.now()

module.exports = class LFO

  frame: null

  # function responsible for the easing.
  # function will receive time values and generate numbers from -1 to 1
  funk: null

  constructor: ( @speed = 1, @funk = Math.sin ) ->
    @reset()

    @speed = @speed * 1000

    funk = Math.sin

  reset: ->
    @frame = 0

  tick: ( gain = 1 ) ->
    @frame++

    return @funk ( performance.now() / @speed ) * gain