OpenColorIO: upgrade to version 2.0.0

Ref T84819

Build System
============

This is an API breaking new version, and the updated code only builds with
OpenColorIO 2.0 and later. Adding backwards compatibility was too complicated.

* Tinyxml was replaced with Expat, adding a new dependency.
* Yaml-cpp is now built as a dependency on Unix, as was already done on Windows.
* Removed currently unused LCMS code.
* Pystring remains built as part of OCIO itself, since it has no good build system.
* Linux and macOS check for the OpenColorIO verison, and disable it if too old.

Ref D10270

Processors and Transforms
=========================

CPU processors now need to be created to do CPU processing. These are cached
internally, but the cache lookup is not fast enough to execute per pixel or
texture sample, so for performance these are now also exposed in the C API.

The C API for transforms will no longer be needed afer all changes, so remove
it to simplify the API and fallback implementation.

Ref D10271

Display Transforms
==================

Needs a bit more manual work constructing the transform. LegacyViewingPipeline
could also have been used, but isn't really any simpler and since it's legacy
we better not rely on it.

We moved more logic into the opencolorio module, to simplify the API. There is
no need to wrap a dozen functions just to be able to do this in C rather than C++.
It's also tightly coupled to the GPU shader logic, and so should be in the same
module.

Ref D10271

GPU Display Shader
==================

To avoid baking exposure and gamma into the GLSL shader and requiring slow
recompiles when tweaking, we manually apply them in the shader. This leads
to some logic duplicaton between the CPU and GPU display processor, but it
seems unavoidable.

Caching was also changed. Previously this was done both on the imbuf and
opencolorio module levels. Now it's all done in the opencolorio module by
simply matching color space names. We no longer use cacheIDs from OpenColorIO
since computing them is expensive, and they are unlikely to match now that
more is baked into the shader code.

Shaders can now use multiple 2D textures, 3D textures and uniforms, rather
than a single 3D texture. So allocating and binding those adds some code.

Color space conversions for blending with overlays is now hardcoded in the
shader. This was using harcoded numbers anyway, if this every becomes a
general OpenColorIO transform it can be changed, but for now there is no
point to add code complexity.

Ref D10273

CIE XYZ
=======

We need standard CIE XYZ values for rendering effects like blackbody emission.
The relation to the scene linear role is based on OpenColorIO configuration.

In OpenColorIO 2.0 configs roles can no longer have the same name as color
spaces, which means our XYZ role and colorspace in the configuration give an
error.

Instead use the new standard aces_interchange role, which relates scene linear
to a known scene referred color space. Compatibility with the old XYZ role is
preserved, if the configuration file has no conflicting names.

Also includes a non-functional change to the configuraton file to use an
XYZ-to-ACES matrix instead of REC709-to-ACES, makes debugging a little easier
since the matrix is the same one we have in the code now and that is also
found easily in the ACES specs.

Ref D10274

1 files changed, 7 insertions, 7 deletions

diff --git a/build_files/build_environment/cmake/versions.cmake b/build_files/build_environment/cmake/versions.cmake
index 76417b59bb3..3a44977e4d3 100644
--- a/build_files/build_environment/cmake/versions.cmake
+++ b/build_files/build_environment/cmake/versions.cmake
@@ -109,9 +109,9 @@ set(OPENCOLLADA_VERSION v1.6.68)
 set(OPENCOLLADA_URI https://github.com/KhronosGroup/OpenCOLLADA/archive/${OPENCOLLADA_VERSION}.tar.gz)
 set(OPENCOLLADA_HASH ee7dae874019fea7be11613d07567493)
 
-set(OPENCOLORIO_VERSION 1.1.1)
+set(OPENCOLORIO_VERSION 2.0.0)
 set(OPENCOLORIO_URI https://github.com/AcademySoftwareFoundation/OpenColorIO/archive/v${OPENCOLORIO_VERSION}.tar.gz)
-set(OPENCOLORIO_HASH 23d8b9ac81599305539a5a8674b94a3d)
+set(OPENCOLORIO_HASH 1a2e3478b6cd9a1549f24e1b2205e3f0)
 
 set(LLVM_VERSION 9.0.1)
 set(LLVM_URI https://github.com/llvm/llvm-project/releases/download/llvmorg-${LLVM_VERSION}/llvm-${LLVM_VERSION}.src.tar.xz)
@@ -257,9 +257,9 @@ set(YAMLCPP_VERSION 0.6.3)
 set(YAMLCPP_URI https://codeload.github.com/jbeder/yaml-cpp/tar.gz/yaml-cpp-${YAMLCPP_VERSION})
 set(YAMLCPP_HASH b45bf1089a382e81f6b661062c10d0c2)
 
-set(LCMS_VERSION 2.9)
-set(LCMS_URI https://nchc.dl.sourceforge.net/project/lcms/lcms/${LCMS_VERSION}/lcms2-${LCMS_VERSION}.tar.gz)
-set(LCMS_HASH 8de1b7724f578d2995c8fdfa35c3ad0e)
+set(EXPAT_VERSION 2_2_10)
+set(EXPAT_URI https://github.com/libexpat/libexpat/archive/R_${EXPAT_VERSION}.tar.gz)
+set(EXPAT_HASH 7ca5f09959fcb9a57618368deb627b9f)
 
 set(PUGIXML_VERSION 1.10)
 set(PUGIXML_URI https://github.com/zeux/pugixml/archive/v${PUGIXML_VERSION}.tar.gz)
@@ -314,8 +314,8 @@ set(MESA_URI ftp://ftp.freedesktop.org/pub/mesa/mesa-${MESA_VERSION}.tar.xz)
 set(MESA_HASH d60828056d77bfdbae0970f9b15fb1be)
 
 set(NASM_VERSION 2.15.02)
-set(NASM_URI https://www.nasm.us/pub/nasm/releasebuilds/${NASM_VERSION}/nasm-${NASM_VERSION}.tar.xz)
-set(NASM_HASH f4fd1329b1713e1ccd34b2fc121c4bcd278c9f91cc4cb205ae8fcd2e4728dd14)
+set(NASM_URI https://github.com/netwide-assembler/nasm/archive/nasm-${NASM_VERSION}.tar.gz)
+set(NASM_HASH aded8b796c996a486a56e0515c83e414116decc3b184d88043480b32eb0a8589)
 
 set(XR_OPENXR_SDK_VERSION 1.0.8)
 set(XR_OPENXR_SDK_URI https://github.com/KhronosGroup/OpenXR-SDK/archive/release-${XR_OPENXR_SDK_VERSION}.tar.gz)