class Capybara::Screenshot::Diff::Drivers::VipsDriver

Constants

MAX_FILENAME_LENGTH

Public Instance Methods

add_black_box(memo, region) click to toggle source
# File lib/capybara/screenshot/diff/drivers/vips_driver.rb, line 52
def add_black_box(memo, region)
  return memo unless region

  memo.draw_rect([0, 0, 0, 0], *region.to_top_left_corner_coordinates, fill: true)
end
crop(region, i) click to toggle source
# File lib/capybara/screenshot/diff/drivers/vips_driver.rb, line 38
def crop(region, i)
  i.crop(*region.to_top_left_corner_coordinates)
rescue Vips::Error => e
  warn(
    "[capybara-screenshot-diff] Crop has been failed for " \
    "{ region: #{region.to_top_left_corner_coordinates.inspect}, image: #{dimension(i).join("x")} }"
  )
  raise e
end
difference_level(diff_mask, old_img, _region = nil) click to toggle source
# File lib/capybara/screenshot/diff/drivers/vips_driver.rb, line 58
def difference_level(diff_mask, old_img, _region = nil)
  VipsUtil.difference_area_size_by(diff_mask).to_f / image_area_size(old_img)
end
dimension(image) click to toggle source
# File lib/capybara/screenshot/diff/drivers/vips_driver.rb, line 92
def dimension(image)
  [width_for(image), height_for(image)]
end
draw_rectangles(images, region, rgba, offset: 0) click to toggle source
# File lib/capybara/screenshot/diff/drivers/vips_driver.rb, line 96
def draw_rectangles(images, region, rgba, offset: 0)
  images.map do |image|
    image.draw_rect(rgba, region.left - offset, region.top - offset, region.width + (offset * 2), region.height + (offset * 2))
  end
end
filter_image_with_median(image, median_filter_window_size) click to toggle source
# File lib/capybara/screenshot/diff/drivers/vips_driver.rb, line 48
def filter_image_with_median(image, median_filter_window_size)
  image.median(median_filter_window_size)
end
find_difference_region(comparison) click to toggle source
# File lib/capybara/screenshot/diff/drivers/vips_driver.rb, line 21
def find_difference_region(comparison)
  new_image, base_image, options = comparison.new_image, comparison.base_image, comparison.options

  diff_mask = VipsUtil.difference_mask(base_image, new_image, options[:color_distance_limit])
  region = VipsUtil.difference_region_by(diff_mask)
  region = nil if region && same_as?(region, base_image)

  result = Difference.new(region, {}, comparison)

  unless result.blank?
    result.meta[:difference_level] = difference_level(diff_mask, base_image) if comparison.options[:tolerance]
    result.meta[:diff_mask] = diff_mask
  end

  result
end
from_file(filename) click to toggle source
# File lib/capybara/screenshot/diff/drivers/vips_driver.rb, line 83
def from_file(filename)
  result = ::Vips::Image.new_from_file(filename.to_s)

  result = result.colourspace(:srgb) if result.bands < 3
  result = result.bandjoin(255) if result.bands == 3

  result
end
highlight_mask(diff_mask, merged_image, color: DEFAULT_HIGHLIGHT_COLOR) click to toggle source
# File lib/capybara/screenshot/diff/drivers/vips_driver.rb, line 110
def highlight_mask(diff_mask, merged_image, color: DEFAULT_HIGHLIGHT_COLOR)
  diff_mask.ifthenelse(color, merged_image * 0.75)
end
load_images(old_file_name, new_file_name) click to toggle source
# File lib/capybara/screenshot/diff/drivers/vips_driver.rb, line 79
def load_images(old_file_name, new_file_name)
  [from_file(old_file_name), from_file(new_file_name)]
end
merge(new_image, base_image) click to toggle source
# File lib/capybara/screenshot/diff/drivers/vips_driver.rb, line 106
def merge(new_image, base_image)
  base_image.composite2(new_image, :over)
end
resize_image_to(image, new_width, new_height) click to toggle source
# File lib/capybara/screenshot/diff/drivers/vips_driver.rb, line 75
def resize_image_to(image, new_width, new_height)
  image.resize(new_width.to_f / new_height)
end
same_pixels?(comparison) click to toggle source
# File lib/capybara/screenshot/diff/drivers/vips_driver.rb, line 102
def same_pixels?(comparison)
  (comparison.new_image == comparison.base_image).min == 255
end
save_image_to(image, filename) click to toggle source

Vips could not work with the same file. Per each process we require to create new file

# File lib/capybara/screenshot/diff/drivers/vips_driver.rb, line 65
def save_image_to(image, filename)
  # Dir::Tmpname will happily produce tempfile names that are too long for most unix filesystems,
  # which leads to "unix error: File name too long". Apply a limit to avoid this.
  limited_filename = filename.to_s[-MAX_FILENAME_LENGTH..] || filename.to_s
  ::Dir::Tmpname.create([limited_filename, PNG_EXTENSION]) do |tmp_image_filename|
    image.write_to_file(tmp_image_filename)
    FileUtils.mv(tmp_image_filename, filename)
  end
end

Private Instance Methods

same_as?(region, base_image) click to toggle source
# File lib/capybara/screenshot/diff/drivers/vips_driver.rb, line 116
def same_as?(region, base_image)
  region.x.zero? &&
    region.y.zero? &&
    region.height == height_for(base_image) &&
    region.width == width_for(base_image)
end