Takes a screenshot of a inspector window from Unity and crops out the largest component. Useful for generating images for documentation. Like so: https://twitter.com/shanecelis/status/899218702805209088

crop-component.rb

#!/opt/local/bin/ruby1.8
#
# crop-component
#
# Takes a screenshot of a inspector window from Unity and crops out the largest
# component.  Useful for generating documentation.
#

# Original code Copyright (c) 2017 Shane Celis[1]
# Licensed under the MIT License[2]
#
# This comment generated by code-cite[3].
#
# [1]: https://twitter.com/shanecelis
# [2]: https://opensource.org/licenses/MIT
# [3]: https://github.com/shanecelis/code-cite

require 'RMagick'
require 'optparse'

# http://ruby-doc.org/stdlib-2.4.1/libdoc/optparse/rdoc/OptionParser.html
options = {}
OptionParser.new do |opts|
  opts.banner = "usage: crop-component [-v] <src> <dest>"

  opts.on("-v", "--[no-]verbose", "Run verbosely") do |v|
    options[:verbose] = v
  end
end.parse!

if ARGV.length != 2 then
  puts "usage: crop-component <src> <dest>"
  puts "Crops the largest component shown in a unity inspector window."
  exit 2
end

file = ARGV[0]
dest = ARGV[1]
  img = Magick::Image::read(file).first
  width = img.columns
  puts "width ", width, " yeah"
  lastRow = -1
  matchCount = 0
  # 7a7a7a
  #lineColor = Magick::Pixel.new(122, 122, 122, 255)
  # lineColor = Magick::Pixel.new(31354, 31354, 31354, 0)
  lineColor = Magick::Pixel.new(29812, 29812, 29812, 0)
  #backgroundColor = Magick::Pixel.new(49858, 49858, 49858, 0)
  rows = []
  img.each_pixel do | pixel, c, r |
    if r <= 82
      next
    end
    # puts pixel
    if lastRow != r then
      p = matchCount.to_f/width
      if p > 0.9 then
        puts "#{p} proportion match on row #{r}"
        rows.push(r)
      end
      matchCount = 0
      lastRow = r
    end
    if (pixel <=> lineColor) == 0 then
      matchCount += 1
    end
  end

rowDeltas = rows.each_cons(2).map { |a, b| b - a }
i = rowDeltas.rindex(rowDeltas.max)
# puts "max on index #{i}"

# puts rows
if i != nil && i < rows.length then
  top = rows[i]
  bottom = rows[i + 1] - 1

  cropped = img.crop(0, top, width, bottom - top)
  w = cropped.columns
  h = cropped.rows
  cropped.resize!(250, 250.0/w * h)#, cropped.columns)
  cropped.write dest
else
  puts "Problem"
  exit 1
end