💥 Change perceived_lightness to return a float

Author: bash

crates/pycolorsaurus/src/lib.rs

@@ -197,10 +197,7 @@ impl Color {
         self.0.scale_to_8bit().2
     }
 
-    /// The perceived lightness of the color
-    /// as a value between 0 (black) and 100 (white)
-    /// where 50 is the perceptual "middle grey".
-    fn perceived_lightness(&self) -> u8 {
+    fn perceived_lightness(&self) -> f32 {
         self.0.perceived_lightness()
     }
 

crates/terminal-colorsaurus/src/color.rs

@@ -12,16 +12,18 @@ pub struct Color {
 }
 
 impl Color {
-    /// The perceived lightness of the color
-    /// as a value between `0` (black) and `100` (white)
-    /// where `50` is the perceptual "middle grey".
+    /// Perceptual lightness (L*) as a value between 0.0 (black) and 1.0 (white)
+    /// where 0.5 is the perceptual middle gray.
+    ///
+    /// Note that the color's alpha is ignored.
     /// ```
     /// # use terminal_colorsaurus::Color;
     /// # let color = Color::default();
-    /// let is_dark = color.perceived_lightness() <= 50;
+    /// let is_dark = color.perceived_lightness() <= 0.5;
     /// ```
-    pub fn perceived_lightness(&self) -> u8 {
-        (self.perceived_lightness_f32() * 100.) as u8
+    pub fn perceived_lightness(&self) -> f32 {
+        let color = xterm_color::Color::rgb(self.r, self.g, self.b);
+        color.perceived_lightness()
     }
 
     /// Converts the color to 8 bit precision per channel by scaling each channel.
@@ -41,11 +43,6 @@ impl Color {
             scale_to_u8(self.b),
         )
     }
-
-    pub(crate) fn perceived_lightness_f32(&self) -> f32 {
-        let color = xterm_color::Color::rgb(self.r, self.g, self.b);
-        color.perceived_lightness()
-    }
 }
 
 fn scale_to_u8(channel: u16) -> u8 {
@@ -97,7 +94,7 @@ mod tests {
     #[test]
     fn black_has_perceived_lightness_zero() {
         let black = Color::default();
-        assert_eq!(0, black.perceived_lightness())
+        assert_eq!(0.0, black.perceived_lightness())
     }
 
     #[test]
@@ -107,6 +104,6 @@ mod tests {
             g: u16::MAX,
             b: u16::MAX,
         };
-        assert_eq!(100, white.perceived_lightness())
+        assert_eq!(1.0, white.perceived_lightness())
     }
 }

crates/terminal-colorsaurus/src/color_scheme_tests.rs

@@ -54,9 +54,9 @@ mod dark {
     #[test]
     fn fg_and_bg_both_dark() {
         for (foreground, background) in [(DARK_GRAY, DARKER_GRAY), (DARKER_GRAY, BLACK)] {
-            assert!(foreground.perceived_lightness_f32() < 0.5);
-            assert!(background.perceived_lightness_f32() < 0.5);
-            assert!(foreground.perceived_lightness_f32() != background.perceived_lightness_f32());
+            assert!(foreground.perceived_lightness() < 0.5);
+            assert!(background.perceived_lightness() < 0.5);
+            assert!(foreground.perceived_lightness() != background.perceived_lightness());
 
             let palette = ColorPalette {
                 foreground,
@@ -93,10 +93,10 @@ mod light {
     #[test]
     fn fg_and_bg_both_light() {
         for (foreground, background) in [(LIGHT_GRAY, LIGHTER_GRAY), (LIGHTER_GRAY, WHITE)] {
-            assert!(foreground.perceived_lightness_f32() > 0.5);
-            assert!(background.perceived_lightness_f32() > 0.5);
+            assert!(foreground.perceived_lightness() > 0.5);
+            assert!(background.perceived_lightness() > 0.5);
             assert!(
-                (foreground.perceived_lightness_f32() - background.perceived_lightness_f32()).abs()
+                (foreground.perceived_lightness() - background.perceived_lightness()).abs()
                     >= f32::EPSILON
             );
 

crates/terminal-colorsaurus/src/lib.rs

@@ -111,8 +111,8 @@ pub enum ColorScheme {
 impl ColorPalette {
     /// Determines if the terminal uses a dark or light background.
     pub fn color_scheme(&self) -> ColorScheme {
-        let fg = self.foreground.perceived_lightness_f32();
-        let bg = self.background.perceived_lightness_f32();
+        let fg = self.foreground.perceived_lightness();
+        let bg = self.background.perceived_lightness();
         if bg < fg {
             ColorScheme::Dark
         } else if bg > fg || bg > 0.5 {