diff -r 7abaf1d64719 -r c438a7db7c52 src/gl/common.h
--- a/src/gl/common.h	Mon May 11 12:18:59 2020 +0300
+++ b/src/gl/common.h	Mon Aug 24 23:00:50 2020 +0300
@@ -168,22 +168,37 @@
 		ConditionalLines
 	};
 
+	constexpr ArrayClass ARRAY_CLASSES[] = {ArrayClass::Lines, ArrayClass::Triangles, ArrayClass::Quads, ArrayClass::ConditionalLines};
+	constexpr int NUM_ARRAY_CLASSES = countof(ARRAY_CLASSES);
+
+	// Different ways to render the scene
 	enum class RenderStyle
 	{
+		// Normal rendering style
 		Normal,
+		// Render all polygons as lines
 		Wireframe,
+		// Use green colour for front faces and red colour for back faces
 		BfcRedGreen,
+		// Use a different colour for each object
 		RandomColors,
+		// Render so that the colour of an object has an one to one correspondence with its id
 		PickScene
 	};
-
+	
+	// Different ways to render fragments.
 	// These are also defined in shaders
 	enum class FragmentStyle
 	{
+		// Use normal colours
 		Normal = 0,
+		// Use a distinctive green colour for BFC red/green view
 		BfcGreen = 1,
+		// Use a distinctive red colour for BFC red/green view
 		BfcRed = 2,
+		// Use a colour based on the object to distinguish objects
 		RandomColors = 3,
+		// Use a colour that codes the object's id
 		Id = 4,
 	};