From 6f12a83d67fa87b30c57bf531270029e22b1df2f Mon Sep 17 00:00:00 2001
From: Andrew Belt <andrewpbelt@gmail.com>
Date: Wed, 15 Feb 2023 01:05:55 -0500
Subject: [PATCH] Add color::lerp().

---
 include/color.hpp | 2 ++
 src/color.cpp     | 7 +++++++
 2 files changed, 9 insertions(+)

diff --git a/include/color.hpp b/include/color.hpp
index b0f251ac..a32868f4 100644
--- a/include/color.hpp
+++ b/include/color.hpp
@@ -34,6 +34,8 @@ NVGcolor plus(NVGcolor a, NVGcolor b);
 /** Multiplies color components elementwise. */
 NVGcolor mult(NVGcolor a, NVGcolor b);
 NVGcolor mult(NVGcolor a, float x);
+/** Interpolates RGBA color values. */
+NVGcolor lerp(NVGcolor a, NVGcolor b, float t);
 /** Screen blending with alpha compositing */
 NVGcolor screen(NVGcolor a, NVGcolor b);
 /** Multiplies alpha value. */
diff --git a/src/color.cpp b/src/color.cpp
index e1e04122..3c90a756 100644
--- a/src/color.cpp
+++ b/src/color.cpp
@@ -44,6 +44,13 @@ NVGcolor mult(NVGcolor a, float x) {
 	return a;
 }
 
+NVGcolor lerp(NVGcolor a, NVGcolor b, float t) {
+	NVGcolor c;
+	for (int i = 0; i < 4; i++)
+		c.rgba[i] = a.rgba[i] * (1 - t) + b.rgba[i] * t;
+	return c;
+}
+
 /** Screen blending with alpha compositing */
 NVGcolor screen(NVGcolor a, NVGcolor b) {
 	if (a.a == 0.f)