 
             # Calculate diffuse lighting.
             if pixel.normal
-              @_normal.copy pixel.normal
-              @_normal.x *= -1 if flippedHorizontal
+              _normal.copy pixel.normal
+              _normal.x *= -1 if flippedHorizontal
 
             else
-              @_normal.set 0, 0, 1
-
-            normalLightProduct = THREE.Math.clamp @_normal.dot(inverseLightDirection), 0, 1
+              _normal.set 0, 0, 1
+
+            normalLightProduct = THREE.Math.clamp _normal.dot(inverseLightDirection), 0, 1
 
             lightDiffuseCoefficient = 0.6
             materialDiffuseCoefficient = 1

            else
              lightness = 0.5

            @_color.setHSL hue, saturation, lightness
            destinationColor = @_color

          else
            destinationColor = r: 0, g: 0, b: 0


      true

  drawToContext: (context, renderOptions = {}) ->
    # HACK: Request sprite data already at the top since otherwise ready sometimes doesn't get recomputed in time.
    spriteData = @options.spriteData()
