Try to improve performance for RGB -> HSV and RGB -> HSL

Author: Ogeon

palette/src/hsl.rs

@@ -337,28 +337,33 @@ where
 
         // The hue base is the `1`, `2/6`, `4/6` or 0 part of the hue equation,
         // except it's multiplied by 6 here.
-        let hue_base = x.clone().select(T::from_f64(-4.0), T::zero())
-            * z.clone().select(T::one(), -T::one())
-            + &six;
+        let hue_base = x.clone().select(
+            z.clone().select(T::from_f64(-4.0), T::from_f64(4.0)),
+            T::zero(),
+        ) + &six;
 
         // Each of these is a part of `G - B`, `B - R`, `R - G` or 0 from the
         // hue equation. They become positive, negative or 0, depending on which
         // branch we should be in. This makes the sum of all three combine as
         // expected.
-        let red_m = x.clone().select(red, T::zero()) * y.clone().select(T::one(), -T::one());
-        let green_m = y.clone().select(green, T::zero()) * z.clone().select(T::one(), -T::one());
-        let blue_m = z.select(blue, T::zero()) * y.select(-T::one(), T::one());
+        let red_m = x
+            .clone()
+            .select(y.clone().select(red.clone(), -red), T::zero());
+        let green_m = y
+            .clone()
+            .select(z.clone().select(green.clone(), -green), T::zero());
+        let blue_m = z.select(y.select(-blue.clone(), blue), T::zero());
 
         // This is the hue equation parts combined. The hue base is the constant
         // and the RGB components are masked so up to two of them are non-zero.
         // Once again, this is multiplied by 6, so the chroma isn't multiplied
         // before dividing.
         //
         // We also avoid dividing by 0 for non-SIMD values.
-        let hue = chroma.eq(&T::zero()).lazy_select(
-            || T::zero(),
-            || hue_base + (red_m + green_m + blue_m) / &chroma,
-        );
+        let hue = lazy_select! {
+            if chroma.eq(&T::zero()) => T::zero(),
+            else => hue_base + (red_m + green_m + blue_m) / &chroma,
+        };
 
         // hue will always be within [0, 12) (it's multiplied by 6, compared to
         // the paper), so we can subtract by 6 instead of using % to get it

palette/src/hsv.rs

@@ -335,28 +335,33 @@ where
 
         // The hue base is the `1`, `2/6`, `4/6` or 0 part of the hue equation,
         // except it's multiplied by 6 here.
-        let hue_base = x.clone().select(T::from_f64(-4.0), T::zero())
-            * z.clone().select(T::one(), -T::one())
-            + &six;
+        let hue_base = x.clone().select(
+            z.clone().select(T::from_f64(-4.0), T::from_f64(4.0)),
+            T::zero(),
+        ) + &six;
 
         // Each of these is a part of `G - B`, `B - R`, `R - G` or 0 from the
         // hue equation. They become positive, negative or 0, depending on which
         // branch we should be in. This makes the sum of all three combine as
         // expected.
-        let red_m = x.clone().select(red, T::zero()) * y.clone().select(T::one(), -T::one());
-        let green_m = y.clone().select(green, T::zero()) * z.clone().select(T::one(), -T::one());
-        let blue_m = z.select(blue, T::zero()) * y.select(-T::one(), T::one());
+        let red_m = x
+            .clone()
+            .select(y.clone().select(red.clone(), -red), T::zero());
+        let green_m = y
+            .clone()
+            .select(z.clone().select(green.clone(), -green), T::zero());
+        let blue_m = z.select(y.select(-blue.clone(), blue), T::zero());
 
         // This is the hue equation parts combined. The hue base is the constant
         // and the RGB components are masked so up to two of them are non-zero.
         // Once again, this is multiplied by 6, so the chroma isn't multiplied
         // before dividing.
         //
         // We also avoid dividing by 0 for non-SIMD values.
-        let hue = chroma.eq(&T::zero()).lazy_select(
-            || T::zero(),
-            || hue_base + (red_m + green_m + blue_m) / &chroma,
-        );
+        let hue = lazy_select! {
+            if chroma.eq(&T::zero()) => T::zero(),
+            else => hue_base + (red_m + green_m + blue_m) / &chroma,
+        };
 
         // hue will always be within [0, 12) (it's multiplied by 6, compared to
         // the paper), so we can subtract by 6 instead of using % to get it