Update hsl/hwb to rgb

Author: ntkme

lib/sass/value/color/space/hsl.rb

@@ -29,26 +29,29 @@ def initialize
           end
 
           def convert(dest, hue, saturation, lightness, alpha)
-            scaled_hue = ((hue.nil? ? 0 : hue) / 360.0) % 1
-            scaled_saturation = (saturation.nil? ? 0 : saturation) / 100.0
-            scaled_lightness = (lightness.nil? ? 0 : lightness) / 100.0
+            missing_lightness = lightness.nil?
+            missing_chroma = saturation.nil?
+            missing_hue = hue.nil?
 
-            m2 = if scaled_lightness <= 0.5
-                   scaled_lightness * (scaled_saturation + 1)
-                 else
-                   scaled_lightness + scaled_saturation - (scaled_lightness * scaled_saturation)
-                 end
-            m1 = (scaled_lightness * 2) - m2
+            hue = ((hue.nil? ? 0 : hue) % 360) / 30.0
+            saturation = (saturation.nil? ? 0 : saturation) / 100.0
+            lightness = (lightness.nil? ? 0 : lightness) / 100.0
+
+            a = saturation * [lightness, 1 - lightness].min
+            f = lambda do |n|
+              k = (n + hue) % 12
+              lightness - (a * [-1, [k - 3, 9 - k, 1].min].max)
+            end
 
             SRGB.convert(
               dest,
-              Utils.hue_to_rgb(m1, m2, scaled_hue + (1 / 3.0)),
-              Utils.hue_to_rgb(m1, m2, scaled_hue),
-              Utils.hue_to_rgb(m1, m2, scaled_hue - (1 / 3.0)),
+              f.call(0),
+              f.call(8),
+              f.call(4),
               alpha,
-              missing_lightness: lightness.nil?,
-              missing_chroma: saturation.nil?,
-              missing_hue: hue.nil?
+              missing_lightness:,
+              missing_chroma:,
+              missing_hue:
             )
           end
         end

lib/sass/value/color/space/hwb.rb

@@ -29,28 +29,35 @@ def initialize
           end
 
           def convert(dest, hue, whiteness, blackness, alpha)
-            scaled_hue = (hue.nil? ? 0 : hue) % 360 / 360.0
-            scaled_whiteness = (whiteness.nil? ? 0 : whiteness) / 100.0
-            scaled_blackness = (blackness.nil? ? 0 : blackness) / 100.0
+            missing_hue = hue.nil?
 
-            sum = scaled_whiteness + scaled_blackness
-            if sum > 1
-              scaled_whiteness /= sum
-              scaled_blackness /= sum
-            end
+            hue = ((hue.nil? ? 0 : hue) % 360) / 30.0
+            whiteness = (whiteness.nil? ? 0 : whiteness) / 100.0
+            blackness = (blackness.nil? ? 0 : blackness) / 100.0
 
-            factor = 1 - scaled_whiteness - scaled_blackness
+            sum = whiteness + blackness
+            if sum > 1
+              gray = whiteness / sum
+              SRGB.convert(dest,
+                           gray,
+                           gray,
+                           gray,
+                           alpha,
+                           missing_hue:)
+            else
+              f = lambda do |n|
+                k = (n + hue) % 12
+                0.5 - ([-1, [k - 3, 9 - k, 1].min].max / 2.0)
+              end
 
-            to_rgb = lambda do |hue_|
-              (Utils.hue_to_rgb(0, 1, hue_) * factor) + scaled_whiteness
+              factor = 1 - sum
+              SRGB.convert(dest,
+                           (f.call(0) * factor) + whiteness,
+                           (f.call(8) * factor) + whiteness,
+                           (f.call(4) * factor) + whiteness,
+                           alpha,
+                           missing_hue:)
             end
-
-            SRGB.convert(dest,
-                         to_rgb.call(scaled_hue + (1 / 3.0)),
-                         to_rgb.call(scaled_hue),
-                         to_rgb.call(scaled_hue - (1 / 3.0)),
-                         alpha,
-                         missing_hue: hue.nil?)
           end
         end
 

lib/sass/value/color/space/lch.rb

@@ -27,6 +27,7 @@ def initialize
           def convert(dest, lightness, chroma, hue, alpha)
             missing_chroma = chroma.nil?
             missing_hue = hue.nil?
+
             chroma = 0 if missing_chroma
             hue = 0 if missing_hue
 

lib/sass/value/color/space/oklab.rb

@@ -30,9 +30,11 @@ def convert(dest, lightness, a, b, alpha, # rubocop:disable Naming/MethodParamet
               missing_lightness = lightness.nil?
               missing_a = a.nil?
               missing_b = b.nil?
+
               lightness = 0 if missing_lightness
               a = 0 if missing_a
               b = 0 if missing_b
+
               LMS.convert(
                 dest,
                 ((

lib/sass/value/color/space/oklch.rb

@@ -28,6 +28,7 @@ def initialize
           def convert(dest, lightness, chroma, hue, alpha)
             missing_chroma = chroma.nil?
             missing_hue = hue.nil?
+
             chroma = 0 if missing_chroma
             hue = 0 if missing_hue
 

lib/sass/value/color/space/utils.rb

@@ -31,29 +31,6 @@ module Utils
             LinearChannel.new('z', 0, 1).freeze
           ].freeze
 
-          # Converts a legacy HSL/HWB hue to an RGB channel.
-          #
-          # The algorithm comes from from the CSS3 spec:
-          # http://www.w3.org/TR/css3-color/#hsl-color.
-          # @param m1 [Numeric]
-          # @param m2 [Numeric]
-          # @param hue [Numeric]
-          # @return [Numeric]
-          def hue_to_rgb(m1, m2, hue) # rubocop:disable Naming/MethodParameterName
-            hue += 1 if hue.negative?
-            hue -= 1 if hue > 1
-
-            if hue < 1 / 6.0
-              m1 + ((m2 - m1) * hue * 6)
-            elsif hue < 1 / 2.0
-              m2
-            elsif hue < 2 / 3.0
-              m1 + ((m2 - m1) * ((2 / 3.0) - hue) * 6)
-            else
-              m1
-            end
-          end
-
           # The algorithm for converting a single `srgb` or `display-p3` channel to
           # linear-light form.
           # @param [Numeric]

spec/sass/value/color_legacy_spec.rb

@@ -158,7 +158,7 @@ def legacy_hwb(...)
 
       it 'has HWB channels' do
         expect(color.hue).to eq(120)
-        expect(color.whiteness).to eq(24.360000000000003)
+        expect(color.whiteness).to eq(24.36000000000000)
         expect(color.blackness).to eq(40.36000000000001)
       end