Add channelRgbColors

Color/src/Graphics/Color/Model.hs

@@ -8,6 +8,7 @@
 --
 module Graphics.Color.Model
   ( ColorModel(..)
+  , channelRgbColors
   -- * Alpha
   , Alpha
   , Opaque
@@ -50,3 +51,13 @@ import Graphics.Color.Model.Internal
 import Graphics.Color.Model.RGB
 import Graphics.Color.Model.X
 import Graphics.Color.Model.YCbCr
+import Data.Coerce
+import Data.Proxy
+import Data.List.NonEmpty
+
+-- | Uses `channelColors` to produce actual `RGB` colors for each
+-- channel. Useful for plotting.
+--
+-- @0.4.0
+channelRgbColors :: ColorModel cs e => Proxy (Color cs e) -> NonEmpty (Color RGB Word8)
+channelRgbColors = coerce . channelColors

Color/src/Graphics/Color/Space/Internal.hs

@@ -106,10 +106,12 @@ class (Illuminant i, ColorModel (BaseModel cs) e, ColorModel cs e) =>
   -- @since 0.1.0
   luminance :: (Elevator a, RealFloat a) => Color cs e -> Color (Y i) a
 
-  -- | Drop chromatic information and get only the grayscale information from the
-  -- color. Without knowledge of the source color the produced value is inconsequential.
+  -- | Drop chromatic information and get only the grayscale information from
+  -- the color. Without knowledge of the source color the produced value is
+  -- inconsequential, becaus each class of color spaces has its own notion of
+  -- grayscale (luma, luminocity, in linear or non-linear form, etc.)
   --
-  -- @since 0.3.1
+  -- @since 0.4.0
   grayscale :: Color cs e -> Color X e
 
   -- | Replace the grayscale information, leaving the chromatic portion of the coloer
@@ -119,7 +121,7 @@ class (Illuminant i, ColorModel (BaseModel cs) e, ColorModel cs e) =>
   --
   -- > replaceGrayscale c y = applyGrayscale c (const y)
   --
-  -- @since 0.3.1
+  -- @since 0.4.0
   replaceGrayscale :: Color cs e -> Color X e -> Color cs e
   replaceGrayscale c y = applyGrayscale c (const y)
   {-# INLINE replaceGrayscale #-}
@@ -132,7 +134,7 @@ class (Illuminant i, ColorModel (BaseModel cs) e, ColorModel cs e) =>
   --
   -- > applyGrayscale c f = replaceGrayscale c (f (grayscale c))
   --
-  -- @since 0.3.1
+  -- @since 0.4.0
   applyGrayscale :: Color cs e -> (Color X e -> Color X e) -> Color cs e
   applyGrayscale c f = replaceGrayscale c (f (grayscale c))
   {-# INLINE applyGrayscale #-}