refactoring to have settings and initialize

lib/is_dark.rb

@@ -26,107 +26,114 @@ class IsDark
   NONLINEAR_TRANSFORM_DIVIDER = 1.055
   NONLINEAR_TRANSFORM_OFFSET = 0.055
   RED_LUMINANCE_COEFFICIENT = 0.2126
+  DEFAULT_PERCENT_OF_DOTS = 80
+  DEFAULT_MATRIX_RANGE = (0..10).freeze
+  DEFAULT_DEBUG_FILE_PATH = '/tmp/is_dark_debug_file.pdf'
 
   @r = 0
   @g = 0
   @b = 0
   @colorset = MAXIMUM_COLOR_DEPTH
+  @percent = DEFAULT_PERCENT_OF_DOTS
+  @matrix = DEFAULT_MATRIX_RANGE
+  @with_not_detected_as_white = true
   @with_debug = false
   @with_debug_file = false
-  @debug_file_path = '/tmp/is_dark_debug_file.pdf'
+  @debug_file_path = DEFAULT_DEBUG_FILE_PATH
+
+  def initialize(settings)
+    configure(settings) unless settings.nil?
+  end
+
+  def self.configure(settings)
+    @percent = settings[:percent] || 80
+    @matrix = settings[:matrix] || (0..10)
+    @with_not_detected_as_white = settings[:with_not_detected_as_white] || true
+    @with_debug = settings[:with_debug] || false
+    @with_debug_file = settings[:with_debug_file] || false
+    @debug_file_path = settings[:debug_file_path] || '/tmp/is_dark_debug_file.pdf'
+  end
 
   def self.color(hex)
     @r, @g, @b = hex.match(/^#(..)(..)(..)$/).captures.map(&:hex)
     @colorset = MAXIMUM_COLOR_DEPTH
     dark?
   end
 
-  def self.magick_pixel(pix, x = nil, y = nil, set_not_detected_light = true)
+  def self.magick_pixel(pix, x = nil, y = nil)
     @r = pix.red.to_f
     @g = pix.green.to_f
     @b = pix.blue.to_f
     @colorset = MAX_COLOR_VALUE
-    dark?(x, y, set_not_detected_light)
+    dark?(x, y)
   end
 
-  def self.magick_pixel_from_blob(x, y, blob, _set_not_detected_light = true)
+  def self.magick_pixel_from_blob(x, y, blob)
     image = Magick::Image.read(blob).first
     pix = image.pixel_color(x, y)
     magick_pixel(pix, x, y)
   end
 
   # (x, y) is the left corner of an element over a blob, height and width is the element's size
-  def self.magick_area_from_blob(
-    x, y, blob, height, width, percent = 80, range = (0..10), set_not_detected_light = true
-  )
-    @set_not_detected_light = set_not_detected_light
+  def self.magick_area_from_blob(x, y, blob, height, width)
     image = Magick::Image.read(blob).first
     dark = false
     dots = []
-    range.each do |xx|
-      range.each do |yy|
+    @matrix.each do |xx|
+      @matrix.each do |yy|
         dots << { x: (x + (width * xx / 10)).to_i, y: (y + (height * yy / 10)).to_i }
       end
     end
 
     points = 0
     if @with_debug_file
-      oldx = false
-      oldy = false
+      old_x = false
+      old_y = false
     end
-    p '====================================================================' if @with_debug
+    p '==================================================================================' if @with_debug
     dots.each do |dot|
       x = dot[:x].to_i
       y = dot[:y].to_i
       pix = image.pixel_color(x, y)
-      l = magick_pixel(pix, x, y, set_not_detected_light)
+      l = magick_pixel(pix, x, y)
       points += 1 if l
       next unless @with_debug_file
 
-      draw_debug_files(image, x, y, oldx, oldy)
-      oldy = y
-      oldx = x
+      draw_debug_files(image, x, y, old_x, old_y)
+      old_y = y
+      old_x = x
     end
-    dark = true if points >= (dots.length / 100) * percent
+    dark = true if points >= (dots.length / 100) * @percent
     if @with_debug
       p '=================================================================================='
       p "Total Points: #{dots.length}, dark points amount:#{points}"
-      p "Is \"invert to white not detectd pixels\" option enabled?:#{set_not_detected_light}"
-      p "Signature will be inverted if #{percent}% of dots will be dark"
+      p "Is \"invert to white not detectd pixels\" option enabled?:#{@with_not_detected_as_white}"
+      p "Signature will be inverted if #{@percent}% of dots will be dark"
       p "Is inverted?: #{dark}"
       p "have a look on #{@debug_file_path} file to see your tested area of a blob"
       p '=================================================================================='
     end
     dark
   end
 
-  def self.set_debug_data(show_info = false, draw_file = false)
-    @with_debug = show_info
-    return unless draw_file != false
-
-    @with_debug_file = true
-    @debug_file_path = draw_file
-  end
-
-  def self.draw_debug_files(image, x, y, oldx, oldy)
-    return unless oldx && oldy
+  def self.draw_debug_files(image, x, y, old_x, old_y)
+    return unless old_x && old_y
 
     gc = Magick::Draw.new
-    gc.line(x, y, oldx, oldy)
+    gc.line(x, y, old_x, old_y)
     gc.stroke('black')
     gc.draw(image)
     image.write(@debug_file_path)
   end
 
   # detects a dark color based on luminance W3 standarts ( https://www.w3.org/TR/WCAG20/#relativeluminancedef )
-  def self.dark?(x = nil, y = nil, set_not_detected_light = true)
+  def self.dark?(x = nil, y = nil)
     dark = false
     inverted = false
     pixel = [@r.to_f, @g.to_f, @b.to_f]
     return true if pixel == [0.00, 0.00, 0.00] # hardcoded exception
 
-    # probably not detected pixel color by Imagick, will be considered as "white" if "set_not_detected_light = true"
-    if set_not_detected_light && pixel[0] == 0.0 && pixel[1] == 0.0 && pixel[2] == 0.0
+    if @with_not_detected_as_white && pixel[0] == 0.0 && pixel[1] == 0.0 && pixel[2] == 0.0
       pixel = [MAXIMUM_COLOR_DEPTH, MAXIMUM_COLOR_DEPTH, MAXIMUM_COLOR_DEPTH]
       inverted = true
     end

spec/lib/is_dark_spec.rb

@@ -88,13 +88,7 @@
         y = 120 # coordinate of a left corner of the area's rectangle Y
         cf_height = 64 # height of the area's rectangle
         cf_width = 128 # height of the area's rectangle
-        percent = 70 # percent of detected dark pixels to invert
-        matrix = (1..10) # matrix of dots. Range of matrix to build dots 1..10 - means 10x10
-        # Sometimes Imagick can't detect a pixel or it has no color, so it detects it as (RGB: 0,0,0), the gem has an
-        # option to consider pixels like this as "white", but if you need to disable this option add true or false.
-        with_not_detected = false
-        expect(IsDark.magick_area_from_blob(x, y, TEST_FILE_PATH, cf_height, cf_width, percent, matrix,
-                                            with_not_detected)).to eq(false)
+        expect(IsDark.magick_area_from_blob(x, y, TEST_FILE_PATH, cf_height, cf_width)).to eq(false)
       end
     end
 
@@ -104,13 +98,7 @@
         y = 120 # coordinate of a left corner of the area's rectangle Y
         cf_height = 64 # height of the area's rectangle
         cf_width = 128 # height of the area's rectangle
-        percent = 70 # percent of detected dark pixels to invert
-        matrix = (1..10) # matrix of dots. Range of matrix to build dots 1..10 - means 10x10
-        # Sometimes Imagick can't detect a pixel or it has no color, so it detects it as (RGB: 0,0,0), the gem has
-        # an option to consider pixels like this as "white", but if you need to disable this option add true or false.
-        with_not_detected = false
-        expect(IsDark.magick_area_from_blob(x, y, TEST_FILE_PATH, cf_height, cf_width, percent, matrix,
-                                            with_not_detected)).to eq(false)
+        expect(IsDark.magick_area_from_blob(x, y, TEST_FILE_PATH, cf_height, cf_width)).to eq(false)
       end
     end
 
@@ -120,14 +108,22 @@
         y = 120 # coordinate of a left corner of the area's rectangle Y
         cf_height = 64 # height of the area's rectangle
         cf_width = 128 # height of the area's rectangle
-        percent = 70 # percent of detected dark pixels to invert
+        percent = 70 # percent of detected dark pixels to mark as dark
         matrix = (1..10) # matrix of dots. Range of matrix to build dots 1..10 - means 10x10
         # Sometimes Imagick can't detect a pixel or it has no color, so it detects it as (RGB: 0,0,0), the gem has
-        # an option to consider pixels like this as "white", but if you need to disable this option add true or false.
-        with_not_detected = false
-        IsDark.set_debug_data(true, './is_dark_debug_output.pdf')
-        expect(IsDark.magick_area_from_blob(x, y, TEST_FILE_PATH, cf_height, cf_width, percent, matrix,
-                                            with_not_detected)).to eq(false)
+        # an option to consider pixels like this as "white", but if you need to disable this option add true or false:
+        not_detected = false
+        # generated file with lines through dots of the matrix over a tested area:
+        debug_file_path = './is_dark_debug_file.pdf'
+        IsDark.configure({
+                           percent: percent,
+                           matrix: matrix,
+                           with_not_detected_as_white: not_detected,
+                           with_debug: true,
+                           with_debug_file: true,
+                           debug_file_path: debug_file_path
+                         })
+        expect(IsDark.magick_area_from_blob(x, y, TEST_FILE_PATH, cf_height, cf_width)).to eq(false)
       end
     end
   end