diff --git a/src/r_main.cpp b/src/r_main.cpp
index cbacb93a5..93131b149 100644
--- a/src/r_main.cpp
+++ b/src/r_main.cpp
@@ -472,7 +472,7 @@ void R_InitTextureMapping ()
 	}
 	for (i = 0; i < centerx; i++)
 	{
-		xtoviewangle[i] = (angle_t)(-(signed)xtoviewangle[viewwidth-i-1]);
+		xtoviewangle[i] = (angle_t)(-(signed)xtoviewangle[viewwidth-i]);
 	}
 }
 
diff --git a/src/r_plane.cpp b/src/r_plane.cpp
index aae870fbe..b89a2979e 100644
--- a/src/r_plane.cpp
+++ b/src/r_plane.cpp
@@ -740,6 +740,10 @@ inline void R_MakeSpans (int x, int t1, int b1, int t2, int b2, void (*mapfunc)(
 // in the normal convention for patches, but uses color 0 as a transparent
 // color instead.
 //
+// Note that since ZDoom now uses color 0 as transparent for other purposes,
+// you can use normal texture transparency, so the distinction isn't so
+// important anymore, but you should still be aware of it.
+//
 //==========================================================================
 
 static FTexture *frontskytex, *backskytex;