hue-interpolate.rb

hue-interpolate.rb

require 'date'

# the keyframe colors, specified in rgb for certain hours of the day (0 - 24. 0 & 24 values should be the same.)
$keyframes = {
  0 => [54, 46, 44],
  4 => [204, 59, 22],
  12 => [22, 31, 14],
  24 => [54, 46, 44]
}
# the size of the step to use for the interpolation. 
$num_seconds_per_step = 3

# interpolate function. define the interpolation between a given start value and an end value
def interpolate(start, _end, step, last_step)
  return (_end - start)  * step / last_step + start
end

# calculate the color values for the values between the keyframes, using num_seconds_per_step
def calculate
  # a "sliding window" of values for each keyframe, 2 elements at a time.
  out = {}
  keyframes.keys.each_cons(2) do | x |
    time_start = x.first
    time_end = x.last
    start_color = keyframes[x.first]
    end_color = keyframes[x.last]
    diff = time_end - time_start
    last_step = (diff * 60 * 60)/ $num_seconds_per_step
    for i in 0..last_step
      r = interpolate(start_color[0], end_color[0], i, last_step)
      g = interpolate(start_color[1], end_color[1], i, last_step)
      b = interpolate(start_color[2], end_color[2], i, last_step)

      out[(time_start * 60 * 60) + (i * $num_seconds_per_step)] = [r,g,b]
    end
  end
  return out
end

# this function is called when the lights should be updated with a new value.
# wire up the lights!!
def update_lights(color, current_second)
  puts "--> update lights, color #{color}, second: #{current_second}"
  puts "--> TODO: hook up lights"
end

$out = calculate
last_color = nil

# continuously check the time every second. check the color value for the current second. 
# if it changed, updated the lights. 
while true do
  current_second = Time.now.to_i - Date.today.to_time.to_i
  color = $out[current_second]
  if !color.nil?
      if last_color != color
        #TODO: update the hue lights here. 
        update_lights(color, current_second)
        last_color = color
      else 
        puts "no color change at #{current_second} (color #{color})"
      end
  end
  sleep(1)
end