Improve color negation (#3500)

crates/typst/src/visualize/color.rs

@@ -4,10 +4,9 @@ use std::str::FromStr;
 
 use ecow::{eco_format, EcoString, EcoVec};
 use once_cell::sync::Lazy;
-use palette::convert::FromColorUnclamped;
 use palette::encoding::{self, Linear};
 use palette::{
-    Darken, Desaturate, FromColor, Lighten, Okhsva, OklabHue, RgbHue, Saturate, ShiftHue,
+    Darken, Desaturate, FromColor, Lighten, OklabHue, RgbHue, Saturate, ShiftHue,
 };
 use qcms::Profile;
 
@@ -1010,16 +1009,29 @@ impl Color {
         })
     }
 
-    /// Produces the negative of the color.
+    /// Produces the complementary color using a provided color space.
+    /// You can think of it as the opposite side on a color wheel.
+    ///
+    /// ```example
+    /// #square(fill: yellow)
+    /// #square(fill: yellow.negate())
+    /// #square(fill: yellow.negate(space: rgb))
+    /// ```
     #[func]
-    pub fn negate(self) -> Color {
+    pub fn negate(
-        match self {
+        self,
+        /// The color space used for the transformation. By default, a perceptual color space is used.
+        #[named]
+        #[default(ColorSpace::Oklab)]
+        space: ColorSpace,
+    ) -> Color {
+        let result = match self.to_space(space) {
             Self::Luma(c) => Self::Luma(Luma::new(1.0 - c.luma, c.alpha)),
-            Self::Oklab(c) => Self::Oklab(Oklab::new(c.l, -c.a, -c.b, c.alpha)),
+            Self::Oklab(c) => Self::Oklab(Oklab::new(1.0 - c.l, -c.a, -c.b, c.alpha)),
             Self::Oklch(c) => Self::Oklch(Oklch::new(
-                c.l,
+                1.0 - c.l,
-                -c.chroma,
+                c.chroma,
-                OklabHue::from_degrees(360.0 - c.hue.into_degrees()),
+                OklabHue::from_degrees(c.hue.into_degrees() + 180.0),
                 c.alpha,
             )),
             Self::LinearRgb(c) => Self::LinearRgb(LinearRgb::new(
@@ -1033,18 +1045,19 @@ impl Color {
             }
             Self::Cmyk(c) => Self::Cmyk(Cmyk::new(1.0 - c.c, 1.0 - c.m, 1.0 - c.y, c.k)),
             Self::Hsl(c) => Self::Hsl(Hsl::new(
-                RgbHue::from_degrees(360.0 - c.hue.into_degrees()),
+                RgbHue::from_degrees(c.hue.into_degrees() + 180.0),
                 c.saturation,
                 c.lightness,
                 c.alpha,
             )),
             Self::Hsv(c) => Self::Hsv(Hsv::new(
-                RgbHue::from_degrees(360.0 - c.hue.into_degrees()),
+                RgbHue::from_degrees(c.hue.into_degrees() + 180.0),
                 c.saturation,
                 c.value,
                 c.alpha,
             )),
-        }
+        };
+        result.to_space(self.space())
     }
 
     /// Rotates the hue of the color by a given angle.
@@ -1304,10 +1317,8 @@ impl Color {
     pub fn to_luma(self) -> Self {
         Self::Luma(match self {
             Self::Luma(c) => c,
-            // Perform sRGB gamut mapping by converting to Okhsv first.
+            Self::Oklab(c) => Luma::from_color(c),
-            // This yields better results than clamping.
+            Self::Oklch(c) => Luma::from_color(c),
-            Self::Oklab(c) => Luma::from_color(Okhsva::from_color(c)),
-            Self::Oklch(c) => Luma::from_color(Okhsva::from_color(c)),
             Self::Rgb(c) => Luma::from_color(c),
             Self::LinearRgb(c) => Luma::from_color(c),
             Self::Cmyk(c) => Luma::from_color(c.to_rgba()),
@@ -1320,9 +1331,7 @@ impl Color {
         Self::Oklab(match self {
             Self::Luma(c) => Oklab::from_color(c),
             Self::Oklab(c) => c,
-            // No clamping is necessary for this conversion because the
+            Self::Oklch(c) => Oklab::from_color(c),
-            // lightness property is the same for both Oklab and Oklch.
-            Self::Oklch(c) => Oklab::from_color_unclamped(c),
             Self::Rgb(c) => Oklab::from_color(c),
             Self::LinearRgb(c) => Oklab::from_color(c),
             Self::Cmyk(c) => Oklab::from_color(c.to_rgba()),
@@ -1334,9 +1343,7 @@ impl Color {
     pub fn to_oklch(self) -> Self {
         Self::Oklch(match self {
             Self::Luma(c) => Oklch::from_color(c),
-            // No clamping is necessary for this conversion because the
+            Self::Oklab(c) => Oklch::from_color(c),
-            // lightness property is the same for both Oklab and Oklch.
-            Self::Oklab(c) => Oklch::from_color_unclamped(c),
             Self::Oklch(c) => c,
             Self::Rgb(c) => Oklch::from_color(c),
             Self::LinearRgb(c) => Oklch::from_color(c),
@@ -1349,10 +1356,8 @@ impl Color {
     pub fn to_rgb(self) -> Self {
         Self::Rgb(match self {
             Self::Luma(c) => Rgb::from_color(c),
-            // Perform sRGB gamut mapping by converting to Okhsv first.
+            Self::Oklab(c) => Rgb::from_color(c),
-            // This yields better results than clamping.
+            Self::Oklch(c) => Rgb::from_color(c),
-            Self::Oklab(c) => Rgb::from_color(Okhsva::from_color(c)),
-            Self::Oklch(c) => Rgb::from_color(Okhsva::from_color(c)),
             Self::Rgb(c) => c,
             Self::LinearRgb(c) => Rgb::from_linear(c),
             Self::Cmyk(c) => Rgb::from_color(c.to_rgba()),
@@ -1364,10 +1369,8 @@ impl Color {
     pub fn to_linear_rgb(self) -> Self {
         Self::LinearRgb(match self {
             Self::Luma(c) => LinearRgb::from_color(c),
-            // Perform sRGB gamut mapping by converting to Okhsv first.
+            Self::Oklab(c) => LinearRgb::from_color(c),
-            // This yields better results than clamping.
+            Self::Oklch(c) => LinearRgb::from_color(c),
-            Self::Oklab(c) => LinearRgb::from_color(Okhsva::from_color(c)),
-            Self::Oklch(c) => LinearRgb::from_color(Okhsva::from_color(c)),
             Self::Rgb(c) => LinearRgb::from_color(c),
             Self::LinearRgb(c) => c,
             Self::Cmyk(c) => LinearRgb::from_color(c.to_rgba()),
@@ -1379,10 +1382,8 @@ impl Color {
     pub fn to_cmyk(self) -> Self {
         Self::Cmyk(match self {
             Self::Luma(c) => Cmyk::from_luma(c),
-            // Perform sRGB gamut mapping by converting to Okhsv first.
+            Self::Oklab(c) => Cmyk::from_rgba(Rgb::from_color(c)),
-            // This yields better results than clamping.
+            Self::Oklch(c) => Cmyk::from_rgba(Rgb::from_color(c)),
-            Self::Oklab(c) => Cmyk::from_rgba(Rgb::from_color(Okhsva::from_color(c))),
-            Self::Oklch(c) => Cmyk::from_rgba(Rgb::from_color(Okhsva::from_color(c))),
             Self::Rgb(c) => Cmyk::from_rgba(c),
             Self::LinearRgb(c) => Cmyk::from_rgba(Rgb::from_linear(c)),
             Self::Cmyk(c) => c,
@@ -1394,10 +1395,8 @@ impl Color {
     pub fn to_hsl(self) -> Self {
         Self::Hsl(match self {
             Self::Luma(c) => Hsl::from_color(c),
-            // Perform sRGB gamut mapping by converting to Okhsv first.
+            Self::Oklab(c) => Hsl::from_color(c),
-            // This yields better results than clamping.
+            Self::Oklch(c) => Hsl::from_color(c),
-            Self::Oklab(c) => Hsl::from_color(Okhsva::from_color(c)),
-            Self::Oklch(c) => Hsl::from_color(Okhsva::from_color(c)),
             Self::Rgb(c) => Hsl::from_color(c),
             Self::LinearRgb(c) => Hsl::from_color(Rgb::from_linear(c)),
             Self::Cmyk(c) => Hsl::from_color(c.to_rgba()),
@@ -1409,10 +1408,8 @@ impl Color {
     pub fn to_hsv(self) -> Self {
         Self::Hsv(match self {
             Self::Luma(c) => Hsv::from_color(c),
-            // Perform sRGB gamut mapping by converting to Okhsv first.
+            Self::Oklab(c) => Hsv::from_color(c),
-            // This yields better results than clamping.
+            Self::Oklch(c) => Hsv::from_color(c),
-            Self::Oklab(c) => Hsv::from_color(Okhsva::from_color(c)),
-            Self::Oklch(c) => Hsv::from_color(Okhsva::from_color(c)),
             Self::Rgb(c) => Hsv::from_color(c),
             Self::LinearRgb(c) => Hsv::from_color(Rgb::from_linear(c)),
             Self::Cmyk(c) => Hsv::from_color(c.to_rgba()),

tests/typ/compiler/color.typ

@@ -8,7 +8,7 @@
   spacing: 1fr,
   rect(width: 1cm, fill: cmyk(69%, 11%, 69%, 41%)),
   rect(width: 1cm, fill: c),
-  rect(width: 1cm, fill: c.negate()),
+  rect(width: 1cm, fill: c.negate(space: cmyk)),
 )
 
 #for x in range(0, 11) {
@@ -82,4 +82,4 @@
 // Ref: false
 #test-repr(luma(20%).lighten(50%), luma(60%))
 #test-repr(luma(80%).darken(20%), luma(64%))
-#test-repr(luma(80%).negate(), luma(20%))
+#test-repr(luma(80%).negate(space: luma), luma(20%))

tests/typ/compute/construct.typ

@@ -11,7 +11,7 @@
 // Test color modification methods.
 #test(rgb(25, 35, 45).lighten(10%), rgb(48, 57, 66))
 #test(rgb(40, 30, 20).darken(10%), rgb(36, 27, 18))
-#test(rgb("#133337").negate(), rgb(236, 204, 200))
+#test(rgb("#133337").negate(space: rgb), rgb(236, 204, 200))
 #test(white.lighten(100%), white)
 
 // Color mixing, in Oklab space by default.