fix: Conversion from RGB to HSV

tlux · Sep 15, 2019 · acc644c · acc644c
1 parent 1f65901
commit acc644c
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Showing 3 changed files with 52 additions and 52 deletions.
diff --git a/lib/tint/rgb.ex b/lib/tint/rgb.ex
@@ -121,9 +121,9 @@ defmodule Tint.RGB do
     alias Tint.HSV
 
     def to_hsv(rgb) do
-      red_ratio = Decimal.div(rgb.red, 255)
-      green_ratio = Decimal.div(rgb.green, 255)
-      blue_ratio = Decimal.div(rgb.blue, 255)
+      red_ratio = calc_ratio(rgb.red)
+      green_ratio = calc_ratio(rgb.green)
+      blue_ratio = calc_ratio(rgb.blue)
       rgb_ratios = [red_ratio, green_ratio, blue_ratio]
 
       min_ratio = Enum.reduce(rgb_ratios, &Decimal.min(&1, &2))
@@ -132,9 +132,12 @@ defmodule Tint.RGB do
 
       hue = calc_hue(ratio_delta, max_ratio, rgb_ratios)
       saturation = calc_saturation(ratio_delta, max_ratio)
-      value = calc_value(max_ratio)
 
-      HSV.new(hue, saturation, value)
+      HSV.new(hue, saturation, max_ratio)
+    end
+
+    defp calc_ratio(value) do
+      Decimal.div(value, 255)
     end
 
     defp calc_hue(ratio_delta, max_ratio, rgb_ratios) do
@@ -184,7 +187,5 @@ defmodule Tint.RGB do
         Decimal.div(ratio_delta, max_ratio)
       end
     end
-
-    defp calc_value(max_ratio), do: Decimal.div(max_ratio, 1)
   end
 end
diff --git a/test/tint/hsv_test.exs b/test/tint/hsv_test.exs
@@ -107,29 +107,28 @@ defmodule Tint.HSVTest do
 
   describe "RGB.Convertible.to_rgb/1" do
     test "convert to RGB" do
-      assert RGB.Convertible.to_rgb(HSV.new(0, 0.0, 0.0)) == RGB.new(0, 0, 0)
-
-      assert RGB.Convertible.to_rgb(HSV.new(0, 0.0, 1.0)) ==
-               RGB.new(255, 255, 255)
-
-      assert RGB.Convertible.to_rgb(HSV.new(48.0, 1.0, 1.0)) ==
-               RGB.new(255, 204, 0)
-
-      assert RGB.Convertible.to_rgb(
-               HSV.new(
-                 332.7692307692308,
-                 0.9420289855072463,
-                 0.5411764705882353
-               )
-             ) == RGB.new(138, 8, 67)
-
-      assert RGB.Convertible.to_rgb(
-               HSV.new(
-                 220.67796610169492,
-                 0.2458333333333333,
-                 0.9411764705882353
-               )
-             ) == RGB.new(181, 200, 240)
+      conversions = [
+        {RGB.new(0, 0, 0), HSV.new(0, 0, 0)},
+        {RGB.new(255, 255, 255), HSV.new(0, 0, 1)},
+        {RGB.new(255, 0, 0), HSV.new(0, 1, 1)},
+        {RGB.new(0, 255, 0), HSV.new(120, 1, 1)},
+        {RGB.new(0, 0, 255), HSV.new(240, 1, 1)},
+        {RGB.new(255, 255, 0), HSV.new(60, 1, 1)},
+        {RGB.new(0, 255, 255), HSV.new(180, 1, 1)},
+        {RGB.new(255, 0, 255), HSV.new(300, 1, 1)},
+        {RGB.new(191, 191, 191), HSV.new(0, 0, 0.75)},
+        {RGB.new(128, 128, 128), HSV.new(0, 0, 0.5)},
+        {RGB.new(128, 0, 0), HSV.new(0, 1, 0.5)},
+        {RGB.new(128, 128, 0), HSV.new(60, 1, 0.5)},
+        {RGB.new(0, 128, 0), HSV.new(120, 1, 0.5)},
+        {RGB.new(128, 0, 128), HSV.new(300, 1, 0.5)},
+        {RGB.new(0, 128, 128), HSV.new(180, 1, 0.5)},
+        {RGB.new(0, 0, 128), HSV.new(240, 1, 0.5)}
+      ]
+
+      Enum.each(conversions, fn {rgb, hsv} ->
+        assert RGB.Convertible.to_rgb(hsv) == rgb
+      end)
     end
   end
 end
diff --git a/test/tint/rgb_test.exs b/test/tint/rgb_test.exs
@@ -210,28 +210,28 @@ defmodule Tint.RGBTest do
 
   describe "HSV.Convertible.to_hsv/1" do
     test "convert to HSV" do
-      assert HSV.Convertible.to_hsv(RGB.new(0, 0, 0)) ==
-               HSV.new(0, 0.0, 0.0)
-
-      assert HSV.Convertible.to_hsv(RGB.new(255, 255, 255)) ==
-               HSV.new(0, 0.0, 1.0)
-
-      assert HSV.Convertible.to_hsv(RGB.new(255, 204, 0)) ==
-               HSV.new(48.0, 1.0, 1.0)
-
-      assert HSV.Convertible.to_hsv(RGB.new(138, 8, 67)) ==
-               HSV.new(
-                 Decimal.new("332.7"),
-                 Decimal.new("0.942"),
-                 Decimal.new("0.541")
-               )
-
-      assert HSV.Convertible.to_hsv(RGB.new(181, 200, 240)) ==
-               HSV.new(
-                 Decimal.new("220.6"),
-                 Decimal.new("0.245"),
-                 Decimal.new("0.941")
-               )
+      conversions = [
+        {RGB.new(0, 0, 0), HSV.new(0, 0, 0)},
+        {RGB.new(255, 255, 255), HSV.new(0, 0, 1)},
+        {RGB.new(255, 0, 0), HSV.new(0, 1, 1)},
+        {RGB.new(0, 255, 0), HSV.new(120, 1, 1)},
+        {RGB.new(0, 0, 255), HSV.new(240, 1, 1)},
+        {RGB.new(255, 255, 0), HSV.new(60, 1, 1)},
+        {RGB.new(0, 255, 255), HSV.new(180, 1, 1)},
+        {RGB.new(255, 0, 255), HSV.new(300, 1, 1)},
+        {RGB.new(191, 191, 191), HSV.new(0, 0, 0.749)},
+        {RGB.new(128, 128, 128), HSV.new(0, 0, 0.501)},
+        {RGB.new(128, 0, 0), HSV.new(0, 1, 0.501)},
+        {RGB.new(128, 128, 0), HSV.new(60, 1, 0.501)},
+        {RGB.new(0, 128, 0), HSV.new(120, 1, 0.501)},
+        {RGB.new(128, 0, 128), HSV.new(300, 1, 0.501)},
+        {RGB.new(0, 128, 128), HSV.new(180, 1, 0.501)},
+        {RGB.new(0, 0, 128), HSV.new(240, 1, 0.501)}
+      ]
+
+      Enum.each(conversions, fn {rgb, hsv} ->
+        assert HSV.Convertible.to_hsv(rgb) == hsv
+      end)
     end
   end
 end