From 91c035aab08e631ab7592635ae945c4921cfc696 Mon Sep 17 00:00:00 2001
From: Meghan Denny <hello@nektro.net>
Date: Thu, 14 Sep 2023 19:47:08 -0700
Subject: [PATCH] add CMYK

---
 CMYK.zig | 29 +++++++++++++++++++++++++++++
 mod.zig  |  1 +
 sRGB.zig | 10 ++++++++++
 3 files changed, 40 insertions(+)
 create mode 100644 CMYK.zig

diff --git a/CMYK.zig b/CMYK.zig
new file mode 100644
index 0000000000000000000000000000000000000000..738c5dcc631d1c2c6abd6adf4382b4821838c67f
--- /dev/null
+++ b/CMYK.zig
@@ -0,0 +1,29 @@
+//! object representing a single color in the CMYK colorspace with channel values from 0-1
+
+const std = @import("std");
+const Self = @This();
+
+c: f32, // cyan
+m: f32, // magenta
+y: f32, // yellow
+k: f32, // black
+a: f32, // alpha
+
+pub fn initCMYKA(c: f32, m: f32, y: f32, k: f32, a: f32) Self {
+    std.debug.assert(c >= 0.0 and c <= 1.0);
+    std.debug.assert(m >= 0.0 and m <= 1.0);
+    std.debug.assert(y >= 0.0 and y <= 1.0);
+    std.debug.assert(k >= 0.0 and k <= 1.0);
+    std.debug.assert(a >= 0.0 and a <= 1.0);
+    return Self{
+        .c = c,
+        .m = m,
+        .y = y,
+        .k = k,
+        .a = a,
+    };
+}
+
+pub fn eql(x: Self, y: Self) bool {
+    return x.c == y.c and x.m == y.m and x.y == y.y and x.k == y.k and x.a == y.a;
+}
diff --git a/mod.zig b/mod.zig
index 3068e2b407e22eb6c28394df90b3f90ffba82e36..0ec6c5ec197751f5b06dd8dee9af7de1fbe07c3c 100644
--- a/mod.zig
+++ b/mod.zig
@@ -3,3 +3,4 @@ const color = @This();
 
 pub const sRGB = @import("./sRGB.zig");
 pub const LinearRgb = @import("./LinearRgb.zig");
+pub const CMYK = @import("./CMYK.zig");
diff --git a/sRGB.zig b/sRGB.zig
index 6d3a4ecaa53e0c449c3254ac4c3d9f5f25da1267..20b9cb019ad8591ccee5352062a45906b821a170 100644
--- a/sRGB.zig
+++ b/sRGB.zig
@@ -97,3 +97,13 @@ pub fn to_float(x: Self) Float {
         .a = @as(f32, @floatFromInt(x.a)) / 255.0,
     };
 }
+
+pub fn to_cmyk(x: Self) color.CMYK {
+    const f = x.to_float();
+    const k = 1 - @max(f.r, f.g, f.b);
+    const c = (1 - f.r - k) / (1 - k);
+    const m = (1 - f.g - k) / (1 - k);
+    const y = (1 - f.b - k) / (1 - k);
+    const a = f.a;
+    return color.CMYK.initCMYKA(c, m, y, k, a);
+}
-- 
2.54.0