Merge pull request #2839 from edwloef/remove-palette

get rid of palette dependency in iced-core

Cargo.lock

@@ -2527,7 +2527,6 @@ dependencies = [
  "lilt",
  "log",
  "num-traits",
- "palette",
  "rustc-hash 2.1.1",
  "smol_str",
  "thiserror 1.0.69",

Cargo.toml

@@ -164,7 +164,6 @@ lyon = "1.0"
 lyon_path = "1.0"
 num-traits = "0.2"
 ouroboros = "0.18"
-palette = "0.7"
 png = "0.17"
 pulldown-cmark = "0.12"
 qrcode = { version = "0.13", default-features = false }

core/Cargo.toml

@@ -24,7 +24,6 @@ glam.workspace = true
 lilt.workspace = true
 log.workspace = true
 num-traits.workspace = true
-palette.workspace = true
 rustc-hash.workspace = true
 smol_str.workspace = true
 thiserror.workspace = true

core/src/color.rs

@@ -1,5 +1,3 @@
-use palette::rgb::{Srgb, Srgba};
-
 /// A color in the `sRGB` color space.
 #[derive(Debug, Clone, Copy, PartialEq, Default)]
 pub struct Color {
@@ -242,70 +240,9 @@ macro_rules! color {
     }};
 }
 
-/// Converts from palette's `Rgba` type to a [`Color`].
-impl From<Srgba> for Color {
-    fn from(rgba: Srgba) -> Self {
-        Color::new(rgba.red, rgba.green, rgba.blue, rgba.alpha)
-    }
-}
-
-/// Converts from [`Color`] to palette's `Rgba` type.
-impl From<Color> for Srgba {
-    fn from(c: Color) -> Self {
-        Srgba::new(c.r, c.g, c.b, c.a)
-    }
-}
-
-/// Converts from palette's `Rgb` type to a [`Color`].
-impl From<Srgb> for Color {
-    fn from(rgb: Srgb) -> Self {
-        Color::new(rgb.red, rgb.green, rgb.blue, 1.0)
-    }
-}
-
-/// Converts from [`Color`] to palette's `Rgb` type.
-impl From<Color> for Srgb {
-    fn from(c: Color) -> Self {
-        Srgb::new(c.r, c.g, c.b)
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
-    use palette::blend::Blend;
-
-    #[test]
-    fn srgba_traits() {
-        let c = Color::from_rgb(0.5, 0.4, 0.3);
-        // Round-trip conversion to the palette::Srgba type
-        let s: Srgba = c.into();
-        let r: Color = s.into();
-        assert_eq!(c, r);
-    }
-
-    #[test]
-    fn color_manipulation() {
-        use approx::assert_relative_eq;
-
-        let c1 = Color::from_rgb(0.5, 0.4, 0.3);
-        let c2 = Color::from_rgb(0.2, 0.5, 0.3);
-
-        // Convert to linear color for manipulation
-        let l1 = Srgba::from(c1).into_linear();
-        let l2 = Srgba::from(c2).into_linear();
-
-        // Take the lighter of each of the sRGB components
-        let lighter = l1.lighten(l2);
-
-        // Convert back to our Color
-        let result: Color = Srgba::from_linear(lighter).into();
-
-        assert_relative_eq!(result.r, 0.5);
-        assert_relative_eq!(result.g, 0.5);
-        assert_relative_eq!(result.b, 0.3);
-        assert_relative_eq!(result.a, 1.0);
-    }
 
     #[test]
     fn parse() {

core/src/theme/palette.rs

@@ -1,10 +1,6 @@
 //! Define the colors of a theme.
 use crate::{Color, color};
 
-use palette::color_difference::Wcag21RelativeContrast;
-use palette::rgb::Rgb;
-use palette::{FromColor, Hsl, Mix};
-
 use std::sync::LazyLock;
 
 /// A color palette.
@@ -607,13 +603,20 @@ impl Danger {
     }
 }
 
+struct Hsl {
+    h: f32,
+    s: f32,
+    l: f32,
+    a: f32,
+}
+
 fn darken(color: Color, amount: f32) -> Color {
     let mut hsl = to_hsl(color);
 
-    hsl.lightness = if hsl.lightness - amount < 0.0 {
+    hsl.l = if hsl.l - amount < 0.0 {
         0.0
     } else {
-        hsl.lightness - amount
+        hsl.l - amount
     };
 
     from_hsl(hsl)
@@ -622,10 +625,10 @@ fn darken(color: Color, amount: f32) -> Color {
 fn lighten(color: Color, amount: f32) -> Color {
     let mut hsl = to_hsl(color);
 
-    hsl.lightness = if hsl.lightness + amount > 1.0 {
+    hsl.l = if hsl.l + amount > 1.0 {
         1.0
     } else {
-        hsl.lightness + amount
+        hsl.l + amount
     };
 
     from_hsl(hsl)
@@ -642,17 +645,24 @@ fn deviate(color: Color, amount: f32) -> Color {
 fn muted(color: Color) -> Color {
     let mut hsl = to_hsl(color);
 
-    hsl.saturation = hsl.saturation.min(0.5);
+    hsl.s = hsl.s.min(0.5);
 
     from_hsl(hsl)
 }
 
 fn mix(a: Color, b: Color, factor: f32) -> Color {
-    let a_lin = Rgb::from(a).into_linear();
+    let b_amount = factor.clamp(0.0, 1.0);
-    let b_lin = Rgb::from(b).into_linear();
+    let a_amount = 1.0 - b_amount;
 
-    let mixed = a_lin.mix(b_lin, factor);
+    let a_linear = a.into_linear().map(|c| c * a_amount);
-    Rgb::from_linear(mixed).into()
+    let b_linear = b.into_linear().map(|c| c * b_amount);
+
+    Color::from_linear_rgba(
+        a_linear[0] + b_linear[0],
+        a_linear[1] + b_linear[1],
+        a_linear[2] + b_linear[2],
+        a_linear[3] + b_linear[3],
+    )
 }
 
 fn readable(background: Color, text: Color) -> Color {
@@ -680,27 +690,85 @@ fn readable(background: Color, text: Color) -> Color {
 }
 
 fn is_dark(color: Color) -> bool {
-    to_hsl(color).lightness < 0.6
+    to_hsl(color).l < 0.6
 }
 
 fn is_readable(a: Color, b: Color) -> bool {
-    let a_srgb = Rgb::from(a);
+    relative_contrast(a, b) >= 7.0
-    let b_srgb = Rgb::from(b);
-
-    a_srgb.has_enhanced_contrast_text(b_srgb)
 }
 
+// https://www.w3.org/TR/WCAG21/#dfn-contrast-ratio
 fn relative_contrast(a: Color, b: Color) -> f32 {
-    let a_srgb = Rgb::from(a);
+    let lum_a = relative_luminance(a);
-    let b_srgb = Rgb::from(b);
+    let lum_b = relative_luminance(b);
-
+    (lum_a.max(lum_b) + 0.05) / (lum_a.min(lum_b) + 0.05)
-    a_srgb.relative_contrast(b_srgb)
 }
 
+// https://www.w3.org/TR/WCAG21/#dfn-relative-luminance
+fn relative_luminance(color: Color) -> f32 {
+    let linear = color.into_linear();
+    0.2126 * linear[0] + 0.7152 * linear[1] + 0.0722 * linear[2]
+}
+
+// https://en.wikipedia.org/wiki/HSL_and_HSV#From_RGB
 fn to_hsl(color: Color) -> Hsl {
-    Hsl::from_color(Rgb::from(color))
+    let x_max = color.r.max(color.g).max(color.b);
+    let x_min = color.r.min(color.g).min(color.b);
+    let c = x_max - x_min;
+    let l = x_max.midpoint(x_min);
+
+    let h = if c == 0.0 {
+        0.0
+    } else if x_max == color.r {
+        60.0 * ((color.g - color.b) / c).rem_euclid(6.0)
+    } else if x_max == color.g {
+        60.0 * (((color.b - color.r) / c) + 2.0)
+    } else {
+        // x_max == color.b
+        60.0 * (((color.r - color.g) / c) + 4.0)
+    };
+
+    let s = if l == 0.0 || l == 1.0 {
+        0.0
+    } else {
+        (x_max - l) / l.min(1.0 - l)
+    };
+
+    Hsl {
+        h,
+        s,
+        l,
+        a: color.a,
+    }
 }
 
+// https://en.wikipedia.org/wiki/HSL_and_HSV#HSL_to_RGB
 fn from_hsl(hsl: Hsl) -> Color {
-    Rgb::from_color(hsl).into()
+    let c = (1.0 - (2.0 * hsl.l - 1.0).abs()) * hsl.s;
+    let h = hsl.h / 60.0;
+    let x = c * (1.0 - (h.rem_euclid(2.0) - 1.0).abs());
+
+    let (r1, g1, b1) = if h < 1.0 {
+        (c, x, 0.0)
+    } else if h < 2.0 {
+        (x, c, 0.0)
+    } else if h < 3.0 {
+        (0.0, c, x)
+    } else if h < 4.0 {
+        (0.0, x, c)
+    } else if h < 5.0 {
+        (x, 0.0, c)
+    } else {
+        // h < 6.0
+        (c, 0.0, x)
+    };
+
+    let m = hsl.l - (c / 2.0);
+
+    Color {
+        r: r1 + m,
+        g: g1 + m,
+        b: b1 + m,
+        a: hsl.a,
+    }
 }

examples/color_palette/Cargo.toml

@@ -9,4 +9,4 @@ publish = false
 iced.workspace = true
 iced.features = ["canvas"]
 
-palette.workspace = true
+palette = "0.7"

examples/color_palette/src/main.rs

@@ -46,7 +46,7 @@ pub enum Message {
 impl ColorPalette {
     fn update(&mut self, message: Message) {
         let srgb = match message {
-            Message::RgbColorChanged(rgb) => Rgb::from(rgb),
+            Message::RgbColorChanged(rgb) => to_rgb(rgb),
             Message::HslColorChanged(hsl) => Rgb::from_color(hsl),
             Message::HsvColorChanged(hsv) => Rgb::from_color(hsv),
             Message::HwbColorChanged(hwb) => Rgb::from_color(hwb),
@@ -54,13 +54,13 @@ impl ColorPalette {
             Message::LchColorChanged(lch) => Rgb::from_color(lch),
         };
 
-        self.theme = Theme::new(srgb);
+        self.theme = Theme::new(to_color(srgb));
     }
 
     fn view(&self) -> Element<Message> {
         let base = self.theme.base;
 
-        let srgb = Rgb::from(base);
+        let srgb = to_rgb(base);
         let hsl = palette::Hsl::from_color(srgb);
         let hsv = palette::Hsv::from_color(srgb);
         let hwb = palette::Hwb::from_color(srgb);
@@ -109,7 +109,7 @@ impl Theme {
         let base = base.into();
 
         // Convert to HSL color for manipulation
-        let hsl = Hsl::from_color(Rgb::from(base));
+        let hsl = Hsl::from_color(to_rgb(base));
 
         let lower = [
             hsl.shift_hue(-135.0).lighten(0.075),
@@ -128,12 +128,12 @@ impl Theme {
         Theme {
             lower: lower
                 .iter()
-                .map(|&color| Rgb::from_color(color).into())
+                .map(|&color| to_color(Rgb::from_color(color)))
                 .collect(),
             base,
             higher: higher
                 .iter()
-                .map(|&color| Rgb::from_color(color).into())
+                .map(|&color| to_color(Rgb::from_color(color)))
                 .collect(),
             canvas_cache: canvas::Cache::default(),
         }
@@ -216,14 +216,14 @@ impl Theme {
 
         text.align_y = alignment::Vertical::Bottom;
 
-        let hsl = Hsl::from_color(Rgb::from(self.base));
+        let hsl = Hsl::from_color(to_rgb(self.base));
         for i in 0..self.len() {
             let pct = (i as f32 + 1.0) / (self.len() as f32 + 1.0);
             let graded = Hsl {
                 lightness: 1.0 - pct,
                 ..hsl
             };
-            let color: Color = Rgb::from_color(graded).into();
+            let color: Color = to_color(Rgb::from_color(graded));
 
             let anchor = Point {
                 x: (i as f32) * box_size.width,
@@ -475,3 +475,21 @@ impl ColorSpace for palette::Lch {
         )
     }
 }
+
+fn to_rgb(color: Color) -> Rgb {
+    Rgb {
+        red: color.r,
+        green: color.g,
+        blue: color.b,
+        ..Rgb::default()
+    }
+}
+
+fn to_color(rgb: Rgb) -> Color {
+    Color {
+        r: rgb.red,
+        g: rgb.green,
+        b: rgb.blue,
+        a: 1.0,
+    }
+}