The title says it all, now having curve mapping
enabled in color management settings wouldn't
force fallback from GLSL to CPU based color space
conversion.
Implemented using GLSL API from OpenColorIO library and
some general functions were added to it's c-api:
- OCIO_setupGLSLDraw prepares OpenGL context for GPU-based
transformation for a giver processor.
This function compiles and links shader, sets up it's
argument. After this transformation would be applied
on an image displaying as a 2D texture.
So, glaDrawPixelsTex called after OCIO_setupGLSLDraw will
do a proper color space transform.
- OCIO_finishGLSLDraw restores OpenGL context after all
color-managed display is over.
- OCIO_freeOGLState frees allocated state structure used
for cacheing some GLSL-related stuff.
There're some utility functions in IMB_colormanagent which
are basically proxies to lower level OCIO functions but
which could be used from any place in blender.
Chacheing of movie clip frame on GPU is also removed now,
and either glaDrawPixelsTex or glaDrawPixelsAuto are used
for display now. This is so no code duplication happens
now and no large textures are lurking around in GPU memory.
Known issues:
- Texture buffer and GLSL are no longer checking for
video card capabilities, possibly could lead to some
artifacts on crappy drivers/cards.
- Only float buffers are displaying using GLSL, byte
buffers will still use fallback display method.
This is to be addressed later.
- If RGB curves are used as a part of display transform,
GLSL display will also be disabled. This is also thing
to be solved later.
Additional changes:
- glaDrawPixelsTexScaled will now use RGBA16F as an
internal format of storing textures when it's used
to draw float buffer. This is needed so LUT are
applied without precision loss.
ocio configuration file failed to load
This solves issues with infinite NULL-checks to prevent crashes in
such situations. Currently only happens if there's no configuration
file at all, but could be tweaked further to fallback if this file
isn't usable by blender.
This commit integrates support of OpenColorIO library into build systems.
It also contains C-API for OpenColorIO library which could be used by Blender.
CMake has got find rules familiar to OpenImageIO's one which makes it easier
for build system to find needed libraries and includes. Scons only could use
explicitly defined paths to libraries and includes.
C-API would be compiled and Blender would be linked against C-API and OpenColorIO
but it wouldn't affect on Blender behavior at all.
OpenColorIO could be disabled by setting up WITH_OCIO to Off in CMake and
setting WITH_BF_OCIO in Scons.
