lua add LCD_DEFAULT_FG, fix 2-bit screen fg/bg inversion

Change-Id: Ibe2bc6602ff27524a3b96d9523780acbfbf03c76
diff --git a/apps/plugins/lua/include_lua/draw.lua b/apps/plugins/lua/include_lua/draw.lua
index 7bf71f0..0ee3e93 100644
--- a/apps/plugins/lua/include_lua/draw.lua
+++ b/apps/plugins/lua/include_lua/draw.lua
@@ -350,8 +350,8 @@
 
         if rb.LCD_DEPTH  == 2 then -- invert 2-bit screens
             --vp.drawmode = bit.bxor(vp.drawmode, 4)
-            vp.fg_pattern = 3 - vp.fg_pattern
-            vp.bg_pattern = 3 - vp.bg_pattern
+            opts.fg_pattern = 3 - opts.fg_pattern
+            opts.bg_pattern = 3 - opts.bg_pattern
         end
         rb.set_viewport(opts)
 
diff --git a/apps/plugins/lua/rocklib.c b/apps/plugins/lua/rocklib.c
index 5995fd8..a6a23f3 100644
--- a/apps/plugins/lua/rocklib.c
+++ b/apps/plugins/lua/rocklib.c
@@ -649,6 +649,10 @@
         RB_CONSTANT(LCD_HEIGHT),
         RB_CONSTANT(LCD_WIDTH),
         RB_CONSTANT(SCREEN_MAIN),
+#if LCD_DEPTH > 1
+        RB_CONSTANT(LCD_DEFAULT_FG),
+        RB_CONSTANT(LCD_DEFAULT_BG),
+#endif
 #ifdef HAVE_REMOTE_LCD
         RB_CONSTANT(LCD_REMOTE_DEPTH),
         RB_CONSTANT(LCD_REMOTE_HEIGHT),