From c5c3dd52cc1096b70fdfb95913b4446e1a16a3ca Mon Sep 17 00:00:00 2001
From: Karsten Schmidt <k@thi.ng>
Date: Thu, 9 Feb 2023 14:31:59 +0100
Subject: [PATCH] feat(color): add hue() function

---
 packages/color/src/hue.ts   | 25 +++++++++++++++++++++++++
 packages/color/src/index.ts |  1 +
 2 files changed, 26 insertions(+)
 create mode 100644 packages/color/src/hue.ts

diff --git a/packages/color/src/hue.ts b/packages/color/src/hue.ts
new file mode 100644
index 0000000000..83b5a8a545
--- /dev/null
+++ b/packages/color/src/hue.ts
@@ -0,0 +1,25 @@
+import { DEFAULT, defmulti } from "@thi.ng/defmulti/defmulti";
+import type { TypedColor } from "./api.js";
+import { hsv } from "./hsv/hsv.js";
+import { __dispatch0 } from "./internal/dispatch.js";
+
+/**
+ * Returns the (normalized) hue of given color.
+ *
+ * @remarks
+ * Since LCH uses different hue values than the more familiar HSV/HSL color
+ * wheel, LCH colors will be first converted to HSV to ensure uniform results.
+ */
+export const hue = defmulti<TypedColor<any>, number>(
+	__dispatch0,
+	{
+		hcy: "hsv",
+		hsi: "hsv",
+		hsl: "hsv",
+	},
+	{
+		[DEFAULT]: (col: TypedColor<any>) => hsv(col)[0],
+
+		hsv: (col) => col[0],
+	}
+);
diff --git a/packages/color/src/index.ts b/packages/color/src/index.ts
index 7f68c373ed..3f96ea54ff 100644
--- a/packages/color/src/index.ts
+++ b/packages/color/src/index.ts
@@ -58,6 +58,7 @@ export * from "./color-range.js";
 export * from "./cosine-gradients.js";
 export * from "./distance.js";
 export * from "./gradients.js";
+export * from "./hue.js";
 export * from "./invert.js";
 export * from "./is-black.js";
 export * from "./is-gamut.js";