EEVEE: Implement the missing Sky texture

I'm not sure if the Sky was deliberately left out or was just waiting for a
better moment, but so many I was disappointed that Sky in EEVEE is
completely white.

There are already 2 implementations (osl and gpu) so this is the third one.
Looking at other cases it seems that we are not supposed to share sources
between cycles and the rest? So the new util_sky_model files are just
copies of what is already in cycles, except that the data file uses the RGB
variant of the Hosek/Wilkie model, because we output RGB anyway (but can be
easily changed to XYZ if desired - the results are nearly identical).
I am not sure if it is okay to pass 3*9 float values as 3 mat4 uniforms (I
wanted to use mat3 but it does not work).
Also, should I cache the sky model data between renders if the parameters
do not change?

Reviewed By: fclem, brecht

Differential Revision: https://developer.blender.org/D7108

1 files changed, 1 insertions, 0 deletions

diff --git a/source/blender/imbuf/IMB_colormanagement.h b/source/blender/imbuf/IMB_colormanagement.h
index 3158e3419b0..4530f6c9fc0 100644
--- a/source/blender/imbuf/IMB_colormanagement.h
+++ b/source/blender/imbuf/IMB_colormanagement.h
@@ -72,6 +72,7 @@ BLI_INLINE float IMB_colormanagement_get_luminance(const float rgb[3]);
 BLI_INLINE unsigned char IMB_colormanagement_get_luminance_byte(const unsigned char[3]);
 BLI_INLINE void IMB_colormangement_xyz_to_rgb(float rgb[3], const float xyz[3]);
 BLI_INLINE void IMB_colormangement_rgb_to_xyz(float xyz[3], const float rgb[3]);
+const float *IMB_colormangement_get_xyz_to_rgb(void);
 
 /* ** Color space transformation functions ** */
 void IMB_colormanagement_transform(float *buffer,