From dd6b535521d4d8e5328f6a9ddecfc5e81e60c604 Mon Sep 17 00:00:00 2001
From: Brecht Van Lommel <brecht@blender.org>
Date: Tue, 4 Jun 2024 18:59:45 +0200
Subject: [PATCH] Build: Add USD patch to fix issues with MaterialX EDF on
 Metal

Ref #122575, #118455

Pull Request: https://projects.blender.org/blender/blender/pulls/122725
---
 build_files/build_environment/cmake/usd.cmake |  9 ++--
 .../patches/usd_metal_edf.diff                | 46 +++++++++++++++++++
 2 files changed, 52 insertions(+), 3 deletions(-)
 create mode 100644 build_files/build_environment/patches/usd_metal_edf.diff

diff --git a/build_files/build_environment/cmake/usd.cmake b/build_files/build_environment/cmake/usd.cmake
index ac5ef653d94..9fcb582a5b3 100644
--- a/build_files/build_environment/cmake/usd.cmake
+++ b/build_files/build_environment/cmake/usd.cmake
@@ -119,9 +119,12 @@ ExternalProject_Add(external_usd
     ${PATCH_CMD} -p 1 -d
       ${BUILD_DIR}/usd/src/external_usd <
       ${PATCH_DIR}/usd.diff &&
-  ${PATCH_CMD} -p 1 -d
-    ${BUILD_DIR}/usd/src/external_usd <
-    ${PATCH_DIR}/usd_core_profile.diff
+    ${PATCH_CMD} -p 1 -d
+      ${BUILD_DIR}/usd/src/external_usd <
+      ${PATCH_DIR}/usd_core_profile.diff &&
+    ${PATCH_CMD} -p 1 -d
+      ${BUILD_DIR}/usd/src/external_usd <
+      ${PATCH_DIR}/usd_metal_edf.diff
 
   CMAKE_ARGS
     -DCMAKE_INSTALL_PREFIX=${LIBDIR}/usd
diff --git a/build_files/build_environment/patches/usd_metal_edf.diff b/build_files/build_environment/patches/usd_metal_edf.diff
new file mode 100644
index 00000000000..5acfa7c6e75
--- /dev/null
+++ b/build_files/build_environment/patches/usd_metal_edf.diff
@@ -0,0 +1,46 @@
+From 4f05a62018ee5134843f7cefed826585f13a509b Mon Sep 17 00:00:00 2001
+From: Dhruv Govil <dgovil2@apple.com>
+Date: Mon, 3 Jun 2024 15:31:34 -0700
+Subject: [PATCH] Fix shader compile bug when using EDF in Storm
+
+Fixes
+https://github.com/PixarAnimationStudios/OpenUSD/issues/3105
+
+Thanks to Lee Kerley for the fix
+---
+ pxr/imaging/hdSt/materialXShaderGen.cpp | 8 +++++++-
+ 1 file changed, 7 insertions(+), 1 deletion(-)
+
+diff --git a/pxr/imaging/hdSt/materialXShaderGen.cpp b/pxr/imaging/hdSt/materialXShaderGen.cpp
+index ca1806bf03..8b0e1a3a41 100644
+--- a/pxr/imaging/hdSt/materialXShaderGen.cpp
++++ b/pxr/imaging/hdSt/materialXShaderGen.cpp
+@@ -692,7 +692,6 @@ HdStMaterialXShaderGen<Base>::_EmitConstantsUniformsAndTypeDefs(
+                 mxContext.getOptions().hwDirectionalAlbedoMethod)),
+             mxStage, false);
+     Base::emitLineBreak(mxStage);
+-    Base::emitTypeDefinitions(mxContext, mxStage);
+ 
+     // Add all constants and ensure that values are initialized
+     const mx::VariableBlock& constants = mxStage.getConstantBlock();
+@@ -945,6 +944,10 @@ HdStMaterialXShaderGenGlsl::_EmitMxFunctions(
+     mx::ShaderGenerator::emitLibraryInclude(
+         "stdlib/" + mx::GlslShaderGenerator::TARGET
+         + "/lib/mx_math.glsl", mxContext, mxStage);
++
++    // Add type definitions
++    emitTypeDefinitions(mxContext, mxStage);
++
+     _EmitConstantsUniformsAndTypeDefs(
+         mxContext, mxStage, _syntax->getConstantQualifier());
+ 
+@@ -1106,6 +1109,9 @@ HdStMaterialXShaderGenMsl::_EmitGlslfxMetalShader(
+     addStageUniform(mx::HW::LIGHT_DATA, mx::Type::FLOAT,
+         "shadowOcclusion", mxStage);
+ 
++    // Add type definitions
++    emitTypeDefinitions(mxContext, mxStage);
++
+     // Add type definitions
+     emitConstantBufferDeclarations(mxContext, resourceBindingCtx, mxStage);
+