smooth color cycling backgrounds

color-cycling.coffee

target = $('body')

# get random RGB values so we can change background and link colors
r = Math.floor Math.random() * 241
g = Math.floor Math.random() * 241
b = Math.floor Math.random() * 241

# variables to hold the lighter shade RGB values
# rp1; gp1; bp1; rp2; gp2; bp2; rp3; gp3; bp3

# we'll use these values to calculate lighter shades
p1 = .1
p2 = .15
p3 = .2

# get random intervals used to calculate the changing RGB values
ri = Math.floor(Math.random()*4)
gi = Math.floor(Math.random()*4)
bi = Math.floor(Math.random()*4)

  # // This changes the body background coor
changeBGColor = ->
  if r > 239 || r < 1
    ri = ri * -1
  if g > 239 || g < 1
    gi = gi * -1
  if b > 239 || b < 1
    bi = bi * -1
  r += ri
  g += gi
  b += bi

  target.css("background-color", "rgb(#{r}, #{g}, #{b})")

  # // now lets figure lighter shades and chaneg the background style property
  # // of our banner, centercontent, and rightcontent divs. If you'd rather they
  # //  stayed white, just get rid of the next block of code.
  getLighterRGBShades()



getLighterRGBShades = ->
  rp1 = parseInt (r * p1) + (255 - (255 * p1))
  gp1 = parseInt (g * p1) + (255 - (255 * p1))
  bp1 = parseInt (b * p1) + (255 - (255 * p1))
  rp2 = parseInt (r * p2) + (255 - (255 * p2))
  gp2 = parseInt (g * p2) + (255 - (255 * p2))
  bp2 = parseInt (b * p2) + (255 - (255 * p2))
  rp3 = parseInt (r * p3) + (255 - (255 * p3))
  gp3 = parseInt (g * p3) + (255 - (255 * p3))
  bp3 = parseInt (b * p3) + (255 - (255 * p3))

getLighterRGBShades()
window.setInterval(changeBGColor,400)