updated comments

src/convert.rs

@@ -2,29 +2,24 @@ use num::Float;
 
 use {Alpha, Rgb, Luma, Xyz, Yxy, Lab, Lch, Hsv, Hsl, Color};
 
-///FromColor provides conversion between the colors. It requires from_xyz
-///and derives conversion to other colors as a default from this.
-///
-///This is not optimal in all cases. For example Hsl -> Rgb using this method will
-///result in Hsl -> Rgb -> Xyz -> Rgb. To avoid this the Rgb derivatives
-///like Hsl and Hsv, convert through Rgb as default and Lab derivatives
-///like Lch convert through Lab as default.
+///FromColor provides conversion between the colors. It requires from_xyz and derives conversion
+///to other colors as a default from this. These defaults must be overridden when direct
+///conversion exists between colors. For example, Luma has direct conversion to Rgb.
+///So from_rgb conversion for Luma and from_luma for Rgb is implemented directly.
 pub trait FromColor<T>: Sized
     where T: Float,
 {
     //To implement ColorConvert for a type, a few things must by kept in mind.
     //
-    //First, derived colors like Hsl must override into_rgb and from_rgb and
-    //convert into_xyz and from_xyz via Rgb, as discussed above.
+    //First, derived colors like Hsl must override from_rgb and convert from_xyz via Rgb.
     //
-    //Second, the from for the same color must override the default.
-    //For example, from_rgb and into_rgb for Rgb will convert via Xyz which
-    //needs to be overridden with *input_color and *self to avoid the unnecessary
-    //converison.
+    //Second, the from for the same color must override the default. For example,
+    //from_rgb for Rgb will convert via Xyz which needs to be overridden with self to
+    //avoid the unnecessary converison.
     //
     //Third, if a direct transform exists between the colors, then it should be
     //overridden. For example, Luma has direct conversion to Rgb. So from_rgb conversion
-    //for Luma is implemented.
+    //for Luma and from_luma for Rgb is implemented directly.
 
     ///Convert from XYZ color space
     fn from_xyz(Xyz<T>) -> Self;
@@ -68,29 +63,11 @@ pub trait FromColor<T>: Sized
 
 
 ///IntoColor provides conversion between the colors. It requires into into_xyz
-///and derives conversion to other colors as a default from this.
-///
-///This is not optimal in all cases. For example Hsl -> Rgb using this method will
-///result in Hsl -> Rgb -> Xyz -> Rgb. To avoid this the Rgb derivatives
-///like Hsl and Hsv, convert through Rgb as default and Lab derivatives
-///like Lch convert through Lab as default.
+///and derives conversion to other colors as a default from this. These defaults
+///must be overridden when direct conversion exists between colors.
 pub trait IntoColor<T>: Sized
     where T: Float,
 {
-    //To implement ColorConvert for a type, a few things must by kept in mind.
-    //
-    //First, derived colors like Hsl must override into_rgb and from_rgb and
-    //convert into_xyz and from_xyz via Rgb, as discussed above.
-    //
-    //Second, the from and into for the same color must override the default.
-    //For example, from_rgb and into_rgb for Rgb will convert via Xyz which
-    //needs to be overridden with *input_color and *self to avoid the unnecessary
-    //converison.
-    //
-    //Third, if a direct transform exists between the colors, then it should be
-    //overridden in both the colors. For example, Luma has direct conversion to
-    //Rgb. So into_rgb and from_rgb conversion is implemented in Luma and into_luma
-    //and from_luma is overridden in Rgb to use the conversion from Luma.
 
     ///Convert into XYZ space
     fn into_xyz(self) -> Xyz<T>;