From 3d8c2110462ec72b9d905a84f92ba933db25e6ea Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miloslav=20=C4=8C=C3=AD=C5=BE?= <tastyfish@seznam.cz>
Date: Tue, 25 Sep 2018 10:09:31 +0200
Subject: [PATCH] Add comment

---
 demo2.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/demo2.cpp b/demo2.cpp
index 3a1354b..0b4734d 100644
--- a/demo2.cpp
+++ b/demo2.cpp
@@ -974,6 +974,10 @@ int16_t intensity = 0;
 #endif
 
 #ifndef NO_SHADING
+    /* NOTE: to gain a lot of performance, it's best to have precomputed color
+       color gradients and look the colors up as opposed to calling
+       addIntensity(...), but for the sake of simplicity we don't do it
+       here. */
     if (previousColumn == pixel->position.x)
     {
       color = addIntensity(color,pixelIntensity);