+ Add normal-based coloring

init.lua

@@ -63,7 +63,13 @@ local shade = function( origin, target, background_color )
 			local light = get_light( pointed_thing.above )
 			local distance = vector.distance ( position, origin )
 			local fog = get_fog( distance )
-			local l_color = base_color * light
+			-- TODO: proper lighting based on sun position (LOL)
+			local n = 1 + (
+				pointed_thing.intersection_normal.x +
+				pointed_thing.intersection_normal.y * 3 +
+				pointed_thing.intersection_normal.z * 1
+			) / 12
+			local l_color = math.min( base_color * n * light, 255 )
 			color = math.floor(
 				l_color * ( 1 - fog ) +
 				background_color * fog