From: paramat <mat.gregory@virginmedia.com>
Date: Mon, 6 Feb 2017 21:48:54 +0000 (+0000)
Subject: Face shading: Add shade factor comments
X-Git-Tag: 0.4.16~455
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=8bc6a303b461662b7434a5ee8557292d43682cc9;p=oweals%2Fminetest.git

Face shading: Add shade factor comments
---

diff --git a/src/mesh.cpp b/src/mesh.cpp
index 6a055abb2..a79264ef0 100644
--- a/src/mesh.cpp
+++ b/src/mesh.cpp
@@ -42,8 +42,15 @@ inline static void applyShadeFactor(video::SColor& color, float factor)
 
 void applyFacesShading(video::SColor &color, const v3f &normal)
 {
-	// Many special drawtypes have normals set to 0,0,0 and this
-	// must result in maximum brightness (no face shadng).
+	/*
+		Some drawtypes have normals set to (0, 0, 0), this must result in
+		maximum brightness: shade factor 1.0.
+		Shade factors for aligned cube faces are:
+		+Y 1.000000 sqrt(1.0)
+		-Y 0.447213 sqrt(0.2)
+		+-X 0.670820 sqrt(0.45)
+		+-Z 0.836660 sqrt(0.7)
+	*/
 	float x2 = normal.X * normal.X;
 	float y2 = normal.Y * normal.Y;
 	float z2 = normal.Z * normal.Z;