From e5c869f27b8fc0ea894a4f770e5c9ad40e210322 Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Fri, 23 Oct 2020 17:06:29 +0300
Subject: [PATCH] Add color lighting & darkening functions

---
 libs/gfx/include/psemek/gfx/color.hpp | 40 +++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/libs/gfx/include/psemek/gfx/color.hpp b/libs/gfx/include/psemek/gfx/color.hpp
index c0ccd097..98998c87 100644
--- a/libs/gfx/include/psemek/gfx/color.hpp
+++ b/libs/gfx/include/psemek/gfx/color.hpp
@@ -100,4 +100,44 @@ namespace psemek::gfx
 	static const generic_color magenta{{1.f, 0.f, 1.f, 1.f}};
 	static const generic_color yellow {{1.f, 1.f, 0.f, 1.f}};
 
+	static const generic_color gray {{0.50f, 0.50f, 0.50f, 1.f}};
+
+	template <std::size_t N>
+	geom::vector<float, N> light(geom::vector<float, N> c, float lightness = 0.5f)
+	{
+		for (std::size_t i = 0; i < N; ++i)
+			c[i] = geom::lerp(c[i], 1.f, lightness);
+		return c;
+	}
+
+	template <std::size_t N>
+	geom::vector<float, N> dark(geom::vector<float, N> c, float darkness = 0.5f)
+	{
+		for (std::size_t i = 0; i < N; ++i)
+			c[i] = geom::lerp(c[i], 0.f, darkness);
+		return c;
+	}
+
+	template <std::size_t N>
+	geom::vector<std::uint8_t, N> light(geom::vector<std::uint8_t, N> c, float lightness = 0.5f)
+	{
+		return to_coloru8(light(to_colorf(c), lightness));
+	}
+
+	template <std::size_t N>
+	geom::vector<std::uint8_t, N> dark(geom::vector<std::uint8_t, N> c, float darkness = 0.5f)
+	{
+		return to_coloru8(dark(to_colorf(c), darkness));
+	}
+
+	inline generic_color light(generic_color const & c, float lightness = 0.5f)
+	{
+		return generic_color{light(c.c, lightness)};
+	}
+
+	inline generic_color dark(generic_color const & c, float darkness = 0.5f)
+	{
+		return generic_color{dark(c.c, darkness)};
+	}
+
 }