Resize iOS icons

iOS_icon_resize.rb

#!/usr/bin/env ruby

if not ARGV[0]
	puts "usage: ./script <icon.png>"
	return
end

$icon = ARGV[0]

iPhone_dimensions = [ 29, 40, 57, 60 ]
iPad_dimensions = [ 29, 40, 50, 72, 76 ]

def command (size, retina)
	if retina
		"convert #{$icon} -resize #{2*size}x#{2*size} out-#{size}@2x.png\n"
	else
		"convert #{$icon} -resize #{size}x#{size} out-#{size}.png\n"	
	end
end

command = ""

iPhone_dimensions.each do |size|
	command << command(size, false)
	command << command(size, true)
end

iPad_dimensions.each do |size|
	command << command(size, false)
	command << command(size, true)
end

exec command