more curve functions

Signed-off-by: Mattias Andrée <maandree@operamail.com>

2 files changed, 80 insertions, 5 deletions

diff --git a/info/blueshift.texinfo b/info/blueshift.texinfo
index 8f7e92a..c5c84f1 100644
--- a/info/blueshift.texinfo
+++ b/info/blueshift.texinfo
@@ -339,19 +339,28 @@ Reverse the red, green and blue curves on the
 encoding axis if @code{r}, @code{g} and @code{b}
 are @code{True}, respectively.
 
-@item invert()
+@item rgb_invert()
 Inverts the all values on the colour curves.
 This creates a negative image with inverted gamma.
 
-@item invert(rgb)
+@item rgb_invert(rgb)
 Inverts the all values on the colour curves
 if @code{rgb} is @code{True}.
 
-@item invert(r, g, b)
+@item rgb_invert(r, g, b)
 Inverts the all values on the red, green and
 blue curves if @code{r}, @code{g} and @code{b}
 are @code{True}, respectively.
 
+@item cie_invert()
+Inverts the all values on the colour curves
+using the CIE xyY colour space instead of sRGB.
+
+@item cie_invert(y)
+Inverts the all values on the colour curves
+using the CIE xyY colour space instead of sRGB,
+if @code{y} is @code{true}.
+
 @item sigmoid(r, g, b)
 An inverted sigmoid curve function is applied
 to the values of in red, green and blue curves
@@ -361,6 +370,20 @@ and @code{b} are the curve sigmoid curve
 multipliers for the red, green and blue curves,
 respectively.
 
+@item rgb_limits(rgb_min, rgb_max)
+Changes the black point to @code{rgb_min}, and
+the white point to @code{rgb_max}.
+
+@item rgb_limits(r_min, r_max, g_min, g_max, b_min, b_max)
+Changes the black point to (@code{r_min},
+@code{g_min}, @code{b_min}), and the white
+point to (@code{r_max}, @code{g_max}, @code{b_max}).
+
+@item cie_limits(y_min, y_max)
+Changes the black point to @code{y_min}, and
+the white point to @code{y_max}, using the
+CIE xyY colour space instead of sRGB.
+
 @item manipulate(rgb)
 Applies the function @code{rgb} : float
 @click{} float to colour curves.
diff --git a/src/curve.py b/src/curve.py
index 001108f..c88b02d 100644
--- a/src/curve.py
+++ b/src/curve.py
@@ -351,9 +351,9 @@ def negative(r = True, g = None, b = None):
                 curve[i], curve[j] = curve[j], curve[i]
 
 
-def invert(r = True, g = None, b = None):
+def rgb_invert(r = True, g = None, b = None):
     '''
-    Invert the colour curves (negative image with gamma invertion)
+    Invert the colour curves (negative image with gamma invertion), using sRGB
     
     @param  r:bool   Whether to invert the red curve
     @param  g:bool?  Whether to invert the green curve, defaults to `r` if `None`
@@ -366,6 +366,23 @@ def invert(r = True, g = None, b = None):
             for i in range(i_size):
                 curve[i] = 1 - curve[i]
 
+
+def cie_invert(r = True, g = None, b = None):
+    '''
+    Invert the colour curves (negative image with gamma invertion), using CIE xyY
+    
+    @param  r:bool   Whether to invert the red curve
+    @param  g:bool?  Whether to invert the green curve, defaults to `r` if `None`
+    @param  b:bool?  Whether to invert the blue curve, defaults to `r` if `None`
+    '''
+    if g is None:  g = r
+    if b is None:  b = r
+    for (curve, setting) in curves(r, g, b):
+        if setting:
+            for i in range(i_size):
+                (x, y, Y) = srgb_to_ciexyy(r_curve[i], g_curve[i], b_curve[i])
+                (r_curve[i], g_curve[i], b_curve[i]) = ciexyy_to_srgb(x, y, 1 - Y)
+
     
 def sigmoid(r, g, b):
     '''
@@ -384,6 +401,41 @@ def sigmoid(r, g, b):
                     curve[i] = 0;
 
 
+def rgb_limits(r_min, r_max, g_min = None, g_max = None, b_min = None, b_max = None):
+    '''
+    Changes the black point and the white point, using sRGB
+    
+    @param  r_min:float   The red component value of the black point
+    @param  r_max:float   The red component value of the white point
+    @param  g_min:float?  The green component value of the black point, defaults to `r_min`
+    @param  g_max:float?  The green component value of the white point, defaults to `r_max`
+    @param  b_min:float?  The blue component value of the black point, defaults to `r_min`
+    @param  b_max:float?  The blue component value of the white point, defaults to `r_max`
+    '''
+    if g_min is None:  g_min = r_min
+    if g_max is None:  g_max = r_max
+    if b_min is None:  b_min = r_min
+    if b_max is None:  b_max = r_max
+    for (curve, (level_min, level_max)) in curves((r_min, r_max), (g_min, g_max), (b_min, b_max)):
+        if (level_min != 0) or (level_max != 1):
+            for i in range(i_size):
+                curve[i] = curve[i] * (level_max - level_min) + level_min
+
+
+def cie_limits(level_min, level_max):
+    '''
+    Changes the black point and the white point, using CIE xyY
+    
+    @param  level_min:float   The brightness of the black point
+    @param  level_max:float   The brightness of the white point
+    '''
+    if (level_min != 0) or (level_max != 1):
+        for i in range(i_size):
+            (x, y, Y) = srgb_to_ciexyy(r_curve[i], g_curve[i], b_curve[i])
+            Y = Y * (level_max - level_min) + level_min
+            (r_curve[i], g_curve[i], b_curve[i]) = ciexyy_to_srgb(x, y, Y)
+
+
 def manipulate(r, g = None, b = None):
     '''
     Manipulate the colour curves using a lambda function