Be more consistent about using sRGB in the client.

Also, expose the sRGB C and C^-1 functions.

3 files changed, 16 insertions, 12 deletions

diff --git a/libdimension-python/tests/color.py b/libdimension-python/tests/color.py
index 47ac975..1299a88 100755
--- a/libdimension-python/tests/color.py
+++ b/libdimension-python/tests/color.py
@@ -50,3 +50,4 @@ assert Cyan    == Color(0, 1, 1), Cyan
 
 assert Red + Blue == Magenta, Red + Blue
 assert 0.5*White == Color(0.5, 0.5, 0.5), 0.5*White
+assert White/2 == Color(0.5, 0.5, 0.5), White/2
diff --git a/libdimension-python/wrapper.pxd b/libdimension-python/wrapper.pxd
index 920f6f2..94966f3 100644
--- a/libdimension-python/wrapper.pxd
+++ b/libdimension-python/wrapper.pxd
@@ -155,8 +155,10 @@ cdef extern from "../libdimension/dimension.h":
   dmnsn_color dmnsn_new_color5(double R, double G, double B,
                                double trans, double filter)
 
-  dmnsn_color dmnsn_color_from_sRGB(dmnsn_color color)
+  double dmnsn_sRGB_gamma(double Clinear)
   dmnsn_color dmnsn_color_to_sRGB(dmnsn_color color)
+  double dmnsn_sRGB_inverse_gamma(double CsRGB)
+  dmnsn_color dmnsn_color_from_sRGB(dmnsn_color color)
 
   double dmnsn_color_intensity(dmnsn_color color)
   dmnsn_color dmnsn_color_add(dmnsn_color color1, dmnsn_color color2)
diff --git a/libdimension-python/wrapper.pyx b/libdimension-python/wrapper.pyx
index 5431e75..2ed85e0 100644
--- a/libdimension-python/wrapper.pyx
+++ b/libdimension-python/wrapper.pyx
@@ -465,6 +465,8 @@ cdef class Color:
       return _sRGBColor(dmnsn_color_mul(rhs, (<Color>lhs)._sRGB))
     else:
       return _sRGBColor(dmnsn_color_mul(lhs, (<Color?>rhs)._sRGB))
+  def __truediv__(Color lhs not None, double rhs):
+    return _sRGBColor(dmnsn_color_mul(1/rhs, lhs._sRGB))
 
   def __richcmp__(lhs, rhs, int op):
     cdef clhs = Color(lhs)
@@ -831,9 +833,9 @@ cdef class Diffuse(Finish):
     Keyword arguments:
     diffuse -- the intensity of the diffuse reflection
     """
-    cdef dmnsn_color gray = dmnsn_color_mul(diffuse, dmnsn_white)
-    diffuse = dmnsn_color_intensity(dmnsn_color_from_sRGB(gray))
-    self._finish.diffuse = dmnsn_new_lambertian(diffuse)
+    self._finish.diffuse = dmnsn_new_lambertian(
+      dmnsn_sRGB_inverse_gamma(diffuse)
+    )
 
 cdef class Phong(Finish):
   """Phong specular highlight."""
@@ -841,7 +843,10 @@ cdef class Phong(Finish):
     """
     Create a Phong highlight.
     """
-    self._finish.specular = dmnsn_new_phong(strength, size)
+    self._finish.specular = dmnsn_new_phong(
+      dmnsn_sRGB_inverse_gamma(strength),
+      size
+    )
 
 cdef class Reflection(Finish):
   """Reflective finish."""
@@ -857,10 +862,8 @@ cdef class Reflection(Finish):
     if max is None:
       max = min
 
-    # Use sRGB value because Reflection(0.5) should really mean "reflect half
-    # the light"
-    self._finish.reflection = dmnsn_new_basic_reflection(Color(min)._sRGB,
-                                                         Color(max)._sRGB,
+    self._finish.reflection = dmnsn_new_basic_reflection(Color(min)._c,
+                                                         Color(max)._c,
                                                          falloff)
 
 ############
@@ -1317,9 +1320,7 @@ cdef class PointLight(Light):
     location -- the origin of the light rays
     color    -- the color and intensity of the light
     """
-    # Take the sRGB component because "color = 0.5*White" should really mean
-    # a half-intensity white light
-    self._light = dmnsn_new_point_light(Vector(location)._v, Color(color)._sRGB)
+    self._light = dmnsn_new_point_light(Vector(location)._v, Color(color)._c)
     Light.__init__(self)
 
 ###########