#!/usr/bin/ruby
# rmix - minimalist volume control
# use -h to run horizontal
require "tk"

$mixer = File.open("/dev/mixer", "w+")

# Ruby 1.9 needs signed ints here.
SOUND_MIXER_READ_PCM  = 0x80044d04 - 2**32
SOUND_MIXER_WRITE_PCM = 0xc0044d04 - 2**32
SOUND_MIXER_READ_VOLUME = 0x80044d00 - 2**32
SOUND_MIXER_WRITE_VOLUME = 0xc0044d00 - 2**32

def getvol
  vol = [0].pack("i")
  $mixer.ioctl(SOUND_MIXER_READ_VOLUME, vol)
  vol = vol.unpack("i")[0]
  [vol%256, vol/256]
end

def setvol(left, right)
  vol = [left + right*256].pack("i")
  $mixer.ioctl(SOUND_MIXER_WRITE_VOLUME, vol)
end

root = TkRoot.new {
  geometry ARGV.join(' ')[/-g(?:eometry)?\s*([0-9x+-]*)/, 1]
}

scroll = TkScale.new(root) {
  showvalue false
  command lambda { |vol| setvol(vol, vol) }
  set getvol.first
  if ARGV.include? "-h"
    orient 'horizontal'
  else
    from 100
    to 0
  end
  pack('fill' => 'both', 'expand' => 1)
}
scroll.bind('<MouseWheel>') { |ev| p ev }

TkAfter.new(delay=100, loop=-1) { scroll.set getvol.first }.start

Tk.mainloop