Don't rely on underscore too much

app/assets/javascripts/player/brush.js.coffee

@@ -4,14 +4,6 @@ class AsciiIo.Brush
   @clearCache: ->
     @cache = {}
 
-  @defaultAttrs =
-    fg       : undefined
-    bg       : undefined
-    blink    : false
-    bright   : false
-    italic   : false
-    underline: false
-
   @default: ->
     @_default ||= @create()
 
@@ -29,7 +21,12 @@ class AsciiIo.Brush
     brush
 
   constructor: (options = {}) ->
-    _(this).extend AsciiIo.Brush.defaultAttrs, options
+    @fg        = options.fg
+    @bg        = options.bg
+    @blink     = options.blink
+    @bright    = options.bright
+    @italic    = options.italic
+    @underline = options.underline
 
   hash: ->
     AsciiIo.Brush.hash this

app/assets/javascripts/player/vt/screen_buffer.js.coffee

@@ -245,7 +245,11 @@ class AsciiIo.ScreenBuffer
   repeatLastCharacter: (n = 1) ->
 
   updateBrush: (changes) ->
-    attrs = _.extend({}, @brush.attributes(), changes)
+    attrs = @brush.attributes()
+
+    for attr, val of changes
+      attrs[attr] = val
+
     @brush = AsciiIo.Brush.create attrs
 
   # ----- Scroll control

app/assets/javascripts/player/vt/sgr_interpreter.js.coffee

@@ -8,7 +8,12 @@ class AsciiIo.SgrInterpreter
       n = numbers[i]
 
       if n is 0
-        _(changes).extend AsciiIo.Brush.defaultAttrs
+        changes.fg        = undefined
+        changes.bg        = undefined
+        changes.blink     = false
+        changes.bright    = false
+        changes.italic    = false
+        changes.underline = false
       else if n is 1
         changes.bright = true
       else if n is 3