From 6eeff6672848c9c3e9e260f8e69e5383701ce137 Mon Sep 17 00:00:00 2001
From: faiface <faiface@ksp.sk>
Date: Thu, 23 Mar 2017 23:03:07 +0100
Subject: [PATCH] add ToNRGBA function for performance

---
 color.go | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/color.go b/color.go
index 7345e4a..45d424c 100644
--- a/color.go
+++ b/color.go
@@ -75,10 +75,9 @@ func clamp(x, low, high float64) float64 {
 	return x
 }
 
-// NRGBAModel converts colors to NRGBA format.
-var NRGBAModel = color.ModelFunc(nrgbaModel)
-
-func nrgbaModel(c color.Color) color.Color {
+// ToNRGBA converts a color to NRGBA format. Using this function is preferred to using NRGBAModel,
+// for performance (using NRGBAModel introduced additional unnecessary allocations).
+func ToNRGBA(c color.Color) NRGBA {
 	if c, ok := c.(NRGBA); ok {
 		return c
 	}
@@ -101,3 +100,10 @@ func nrgbaModel(c color.Color) color.Color {
 		float64(a) / 0xffff,
 	}
 }
+
+// NRGBAModel converts colors to NRGBA format.
+var NRGBAModel = color.ModelFunc(nrgbaModel)
+
+func nrgbaModel(c color.Color) color.Color {
+	return ToNRGBA(c)
+}