Refactor hsluv colour conversions to use helpers, for clarity

Author: gravitystorm

lib/glug/hsluv_modifiers.rb

@@ -7,64 +7,65 @@ module Chroma
   # Add hsluv versions of the color functions to chroma
   class Color
     def darkenp(amount = 10)
-      h, s, l = Hsluv.rgb_to_hsluv(rgb.r / 255.0, rgb.g / 255.0, rgb.b / 255.0)
-      new_l = [l - amount, 0].max
-      rgb_values = Hsluv.rgb_prepare(Hsluv.hsluv_to_rgb(h, s, new_l))
-      Chroma.paint("rgb(#{rgb_values[0]}, #{rgb_values[1]}, #{rgb_values[2]})")
+      h, s, l = to_hsluv
+      l = [l - amount, 0].max
+      from_hsluv(h, s, l)
     end
 
     def lightenp(amount = 10)
-      h, s, l = Hsluv.rgb_to_hsluv(rgb.r / 255.0, rgb.g / 255.0, rgb.b / 255.0)
-      new_l = [l + amount, 100].min
-      rgb_values = Hsluv.rgb_prepare(Hsluv.hsluv_to_rgb(h, s, new_l))
-      Chroma.paint("rgb(#{rgb_values[0]}, #{rgb_values[1]}, #{rgb_values[2]})")
+      h, s, l = to_hsluv
+      l = [l + amount, 100].min
+      from_hsluv(h, s, l)
     end
 
     def saturatep(amount = 10)
-      h, s, l = Hsluv.rgb_to_hsluv(rgb.r / 255.0, rgb.g / 255.0, rgb.b / 255.0)
-      new_s = [s + amount, 100].min
-      rgb_values = Hsluv.rgb_prepare(Hsluv.hsluv_to_rgb(h, new_s, l))
-      Chroma.paint("rgb(#{rgb_values[0]}, #{rgb_values[1]}, #{rgb_values[2]})")
+      h, s, l = to_hsluv
+      s = [s + amount, 100].min
+      from_hsluv(h, s, l)
     end
 
     def desaturatep(amount = 10)
-      h, s, l = Hsluv.rgb_to_hsluv(rgb.r / 255.0, rgb.g / 255.0, rgb.b / 255.0)
-      new_s = [s - amount, 0].max
-      rgb_values = Hsluv.rgb_prepare(Hsluv.hsluv_to_rgb(h, new_s, l))
-      Chroma.paint("rgb(#{rgb_values[0]}, #{rgb_values[1]}, #{rgb_values[2]})")
+      h, s, l = to_hsluv
+      s = [s - amount, 0].max
+      from_hsluv(h, s, l)
     end
 
     def greyscalep
-      h, _s, l = Hsluv.rgb_to_hsluv(rgb.r / 255.0, rgb.g / 255.0, rgb.b / 255.0)
-      rgb_values = Hsluv.rgb_prepare(Hsluv.hsluv_to_rgb(h, 0, l))
-      Chroma.paint("rgb(#{rgb_values[0]}, #{rgb_values[1]}, #{rgb_values[2]})")
+      h, _s, l = to_hsluv
+      from_hsluv(h, 0, l)
     end
     alias grayscalep greyscalep
 
     def spinp(amount = 0)
-      h, s, l = Hsluv.rgb_to_hsluv(rgb.r / 255.0, rgb.g / 255.0, rgb.b / 255.0)
-      new_h = (h + amount) % 360
-      rgb_values = Hsluv.rgb_prepare(Hsluv.hsluv_to_rgb(new_h, s, l))
-      Chroma.paint("rgb(#{rgb_values[0]}, #{rgb_values[1]}, #{rgb_values[2]})")
+      h, s, l = to_hsluv
+      h = (h + amount) % 360
+      from_hsluv(h, s, l)
     end
 
     def mixp(other, weight = 50)
       other = other.paint if other.is_a?(String)
       p = weight / 100.0
 
-      h1, s1, l1 = Hsluv.rgb_to_hsluv(rgb.r / 255.0, rgb.g / 255.0, rgb.b / 255.0)
-      h2, s2, l2 = Hsluv.rgb_to_hsluv(other.rgb.r / 255.0, other.rgb.g / 255.0, other.rgb.b / 255.0)
+      h1, s1, l1 = to_hsluv
+      h2, s2, l2 = other.to_hsluv
 
       # Interpolate hue on the shortest path around the color wheel
       h_diff = h2 - h1
       h_diff -= 360 if h_diff > 180
       h_diff += 360 if h_diff < -180
-      new_h = (h1 + h_diff * (1 - p)) % 360
+      h = (h1 + h_diff * (1 - p)) % 360
+      s = s1 * p + s2 * (1 - p)
+      l = l1 * p + l2 * (1 - p)
+
+      from_hsluv(h, s, l)
+    end
 
-      new_s = s1 * p + s2 * (1 - p)
-      new_l = l1 * p + l2 * (1 - p)
+    def to_hsluv
+      Hsluv.rgb_to_hsluv(rgb.r / 255.0, rgb.g / 255.0, rgb.b / 255.0)
+    end
 
-      rgb_values = Hsluv.rgb_prepare(Hsluv.hsluv_to_rgb(new_h, new_s, new_l))
+    def from_hsluv(h, s, l) # rubocop:disable Naming/MethodParameterName
+      rgb_values = Hsluv.rgb_prepare(Hsluv.hsluv_to_rgb(h, s, l))
       Chroma.paint("rgb(#{rgb_values[0]}, #{rgb_values[1]}, #{rgb_values[2]})")
     end
   end