From 63f576aee53caec2589181f3e14cee5dc0970729 Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Sun, 15 Jan 2023 14:23:06 +0300
Subject: [PATCH] Add gfx::blend for colors

---
 libs/gfx/include/psemek/gfx/color.hpp | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/libs/gfx/include/psemek/gfx/color.hpp b/libs/gfx/include/psemek/gfx/color.hpp
index f70e1f20..845776c6 100644
--- a/libs/gfx/include/psemek/gfx/color.hpp
+++ b/libs/gfx/include/psemek/gfx/color.hpp
@@ -83,6 +83,19 @@ namespace psemek::gfx
 		return to_coloru8(lerp(to_colorf(c0), to_colorf(c1), t));
 	}
 
+	inline color_4f blend(color_4f const & c0, color_4f const & c1)
+	{
+		color_4f result = lerp(c0, c1, c1[3]);
+		result[3] = c0[3] * (1.f - c1[3]) + c1[3];
+		return result;
+	}
+
+	template <std::size_t N>
+	auto blend(geom::vector<std::uint8_t, N> const & c0, geom::vector<std::uint8_t, N> const & c1, float t)
+	{
+		return to_coloru8(blend(to_colorf(c0), to_colorf(c1), t));
+	}
+
 	template <std::size_t N>
 	auto to_srgb(geom::vector<float, N> const & c, float g = 1.f / 2.2f)
 	{