Face shading: Add shade factor comments

diff --git a/src/mesh.cpp b/src/mesh.cpp
index 6a055abb255f653cc71e3736d9b9c86a54ad5097..a79264ef0d0d976f73dcb7120f6a3d3f1c1416c4 100644 (file)
--- 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;