2 files changed, 15 insertions, 0 deletions
diff --git a/src/__main__.py b/src/__main__.py
index 6ad21ce..cee2f85 100755
--- a/src/__main__.py
+++ b/src/__main__.py
@@ -55,6 +55,7 @@ def periodically(year, month, day, hour, minute, second, weekday, fade):
     (**) See https://en.wikipedia.org/wiki/Leap_second
     '''
     if fade is None:
+        negative(False, False, False)
         temperature(6500, lambda T : divide_by_maximum(series_d(T)), True)
         temperature(6500, lambda T : clip_whitepoint(simple_whitepoint(T)), True)
         temperature(6500, cmf_2deg, True)
diff --git a/src/curve.py b/src/curve.py
index 8a6b28c..34adf29 100644
--- a/src/curve.py
+++ b/src/curve.py
@@ -263,6 +263,20 @@ def gamma(r, g, b):
                 curve[i] **= level
 
     
+def negative(r, g, b):
+    '''
+    Invert the colour curves (negative image)
+    
+    @param  r:bool  Whether to invert the red curve
+    @param  g:bool  Whether to invert the green curve
+    @param  b:bool  Whether to invert the blue curve
+    '''
+    for (curve, setting) in curves(r, g, b):
+        if setting:
+            for i in range(i_size):
+                curve[i] = 1 - curve[i]
+
+    
 def sigmoid(r, g, b):
     '''
     Apply S-curve correction on the colour curves