From 3e1ccfc89bd506a9a4c7ad2b8759ab8b8387bdf8 Mon Sep 17 00:00:00 2001
From: JGamache-Autodesk <jerry.gamache@autodesk.com>
Date: Tue, 20 Aug 2024 12:08:00 -0400
Subject: [PATCH] Defer to default color management in OCIO code for known
 transforms

Make the OCIO color manager derive from the default color management.
---
 source/MaterialXGenShader/CMakeLists.txt            |  2 +-
 .../OpenColorIOManagementSystem.cpp                 | 13 +++++++++++++
 .../OpenColorIOManagementSystem.h                   |  4 ++--
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/source/MaterialXGenShader/CMakeLists.txt b/source/MaterialXGenShader/CMakeLists.txt
index de922a4e62..b2f48e7e3e 100644
--- a/source/MaterialXGenShader/CMakeLists.txt
+++ b/source/MaterialXGenShader/CMakeLists.txt
@@ -14,6 +14,6 @@ mx_add_library(MaterialXGenShader
 
 if(MATERIALX_BUILD_OCIO)
     find_package(OpenColorIO REQUIRED)
-    target_link_libraries(${TARGET_NAME} OpenColorIO::OpenColorIO)
+    target_link_libraries(${TARGET_NAME} PUBLIC OpenColorIO::OpenColorIO)
     target_compile_definitions(${TARGET_NAME} PUBLIC MATERIALX_BUILD_OCIO)
 endif()
\ No newline at end of file
diff --git a/source/MaterialXGenShader/OpenColorIOManagementSystem.cpp b/source/MaterialXGenShader/OpenColorIOManagementSystem.cpp
index 0a4aa322c1..d2852a6e91 100644
--- a/source/MaterialXGenShader/OpenColorIOManagementSystem.cpp
+++ b/source/MaterialXGenShader/OpenColorIOManagementSystem.cpp
@@ -57,6 +57,7 @@ OpenColorIOManagementSystemPtr OpenColorIOManagementSystem::create(const OCIO::C
 }
 
 OpenColorIOManagementSystem::OpenColorIOManagementSystem(const OCIO::ConstConfigRcPtr& config, const string& target) :
+    DefaultColorManagementSystem(target),
     _target(target),
     _config(std::move(config))
 {
@@ -94,6 +95,11 @@ const char* OpenColorIOManagementSystem::getSupportedColorSpaceName(const char*
 
 NodeDefPtr OpenColorIOManagementSystem::getNodeDef(const ColorSpaceTransform& transform) const
 {
+    // See if the default color management system already handles this:
+    if (auto cmNodeDef = DefaultColorManagementSystem::getNodeDef(transform)) {
+        return cmNodeDef;
+    }
+
     OCIO::ConstProcessorRcPtr processor;
     // Check if directly supported in the config:
     const char* sourceColorSpace = getSupportedColorSpaceName(transform.sourceSpace.c_str());
@@ -162,11 +168,18 @@ NodeDefPtr OpenColorIOManagementSystem::getNodeDef(const ColorSpaceTransform& tr
 
 bool OpenColorIOManagementSystem::hasImplementation(const string& implName) const
 {
+    if (DefaultColorManagementSystem::hasImplementation(implName)) {
+        return true;
+    }
     return _implementations.count(implName);
 }
 
 ShaderNodeImplPtr OpenColorIOManagementSystem::createImplementation(const string& implName) const
 {
+    if (auto impl = DefaultColorManagementSystem::createImplementation(implName)) {
+        return impl;
+    }
+
     if (_implementations.count(implName))
     {
         return OpenColorIONode::create();
diff --git a/source/MaterialXGenShader/OpenColorIOManagementSystem.h b/source/MaterialXGenShader/OpenColorIOManagementSystem.h
index e74325fc39..f81086ffbc 100644
--- a/source/MaterialXGenShader/OpenColorIOManagementSystem.h
+++ b/source/MaterialXGenShader/OpenColorIOManagementSystem.h
@@ -12,7 +12,7 @@
 
 #include <MaterialXCore/Definition.h>
 
-#include <MaterialXGenShader/ColorManagementSystem.h>
+#include <MaterialXGenShader/DefaultColorManagementSystem.h>
 #include <OpenColorIO/OpenColorABI.h>
 #include <OpenColorIO/OpenColorIO.h>
 
@@ -29,7 +29,7 @@ using OpenColorIOManagementSystemPtr = std::shared_ptr<class OpenColorIOManageme
 
 /// @class OpenColorIOManagementSystem
 /// Class for a default color management system.
-class MX_GENSHADER_API OpenColorIOManagementSystem : public ColorManagementSystem
+class MX_GENSHADER_API OpenColorIOManagementSystem : public DefaultColorManagementSystem
 {
   public:
     virtual ~OpenColorIOManagementSystem() { }