From 41660aee20de6d01f1b8cdf0ba2373eb969b6743 Mon Sep 17 00:00:00 2001
From: Thomas Teixeira <thomas.teixeira@startmail.com>
Date: Wed, 1 Nov 2023 11:45:44 +0100
Subject: [PATCH] Fix CMYK from-conversion and add it as possible color
 function

---
 src/cli/cli.rs |  3 ++-
 src/lib.rs     | 16 +++++-----------
 src/parser.rs  | 29 +++++++++++++++++++++++++++++
 3 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/src/cli/cli.rs b/src/cli/cli.rs
index b0cccda..37c6ab9 100644
--- a/src/cli/cli.rs
+++ b/src/cli/cli.rs
@@ -24,7 +24,8 @@ pub fn build_cli() -> Command<'static> {
              \n  - 789\
              \n  - 'rgb(119, 136, 153)'\
              \n  - '119,136,153'\
-             \n  - 'hsl(210, 14.3%, 53.3%)'\n\
+             \n  - 'hsl(210, 14.3%, 53.3%)'\
+             \n  - 'cmyk(22, 11, 0, 40)'\n\
              Alpha transparency is also supported:\
              \n  - '#77889980'\
              \n  - 'rgba(119, 136, 153, 0.5)'\
diff --git a/src/lib.rs b/src/lib.rs
index 31b5784..25248c9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -960,11 +960,11 @@ impl From<&LCh> for Color {
 impl From<&CMYK> for Color {
     fn from(color: &CMYK) -> Self {
         #![allow(clippy::many_single_char_names)]
-        let r = 255.0 * ((1.0 - color.c) / 100.0) * ((1.0 - color.k) / 100.0);
-        let g = 255.0 * ((1.0 - color.m) / 100.0) * ((1.0 - color.k) / 100.0);
-        let b = 255.0 * ((1.0 - color.y) / 100.0) * ((1.0 - color.k) / 100.0);
+        let r = Scalar::round(255.0 * (1.0 - color.c / 100.0) * (1.0 - color.k / 100.0)) as u8;
+        let g = Scalar::round(255.0 * (1.0 - color.m / 100.0) * (1.0 - color.k / 100.0)) as u8;
+        let b = Scalar::round(255.0 * (1.0 - color.y / 100.0) * (1.0 - color.k / 100.0)) as u8;
 
-        Color::from(&RGBA::<f64> {
+        Color::from(&RGBA::<u8> {
             r,
             g,
             b,
@@ -1429,13 +1429,7 @@ impl From<&Color> for CMYK {
         let r = (rgba.r as f64) / 255.0;
         let g = (rgba.g as f64) / 255.0;
         let b = (rgba.b as f64) / 255.0;
-        let biggest = if r >= g && r >= b {
-            r
-        } else if g >= r && g >= b {
-            g
-        } else {
-            b
-        };
+        let biggest = r.max(g).max(b);
         let out_k = 1.0 - biggest;
         let out_c = (1.0 - r - out_k) / biggest;
         let out_m = (1.0 - g - out_k) / biggest;
diff --git a/src/parser.rs b/src/parser.rs
index 3df10b8..b5df433 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -147,6 +147,24 @@ fn parse_numeric_rgb(input: &str) -> IResult<&str, Color> {
     Ok((input, c))
 }
 
+fn parse_cmyk(input: &str) -> IResult<&str, Color> {
+    let (input, _) = tag("cmyk(")(input)?;
+    let (input, _) = space0(input)?;
+    let (input, c) = double(input)?;
+    let (input, _) = parse_separator(input)?;
+    let (input, m) = double(input)?;
+    let (input, _) = parse_separator(input)?;
+    let (input, y) = double(input)?;
+    let (input, _) = parse_separator(input)?;
+    let (input, k) = double(input)?;
+    let (input, _) = space0(input)?;
+    let (input, _) = char(')')(input)?;
+
+    let color = Color::from_cmyk(c, m, y, k);
+
+    Ok((input, color))
+}
+
 fn parse_percentage_rgb(input: &str) -> IResult<&str, Color> {
     let (input, prefixed) = opt(alt((tag("rgb("), tag("rgba("))))(input)?;
     let is_prefixed = prefixed.is_some();
@@ -284,6 +302,7 @@ pub fn parse_color(input: &str) -> Option<Color> {
         all_consuming(parse_hex),
         all_consuming(parse_numeric_rgb),
         all_consuming(parse_percentage_rgb),
+        all_consuming(parse_cmyk),
         all_consuming(parse_hsl),
         all_consuming(parse_hsv),
         all_consuming(parse_gray),
@@ -380,6 +399,16 @@ fn parse_rgb_standalone_syntax() {
     assert_eq!(Some(rgb(1, 2, 3)), parse_color("1,2,3"));
 }
 
+#[test]
+fn parse_cmyk_syntax() {
+    assert_eq!(Some(Color::black()), parse_color("cmyk(0, 0, 0, 100)"));
+    assert_eq!(Some(Color::white()), parse_color("cmyk(0, 0, 0, 0)"));
+    assert_eq!(Some(Color::red()), parse_color("cmyk(0, 100, 100, 0)"));
+    assert_eq!(Some(Color::green()), parse_color("cmyk(100, 0, 100, 50)"));
+    assert_eq!(Some(Color::blue()), parse_color("cmyk(100, 100,0,0)"));
+    assert_eq!(Some(Color::yellow()), parse_color("cmyk(  0,0, 100,   0)"));
+}
+
 #[test]
 fn parse_hsl_syntax() {
     assert_eq!(