Support compiling against imath

cmake/defaults/Packages.cmake

@@ -187,7 +187,7 @@ endif()
 if (PXR_BUILD_IMAGING)
     # --OpenImageIO
     if (PXR_BUILD_OPENIMAGEIO_PLUGIN)
-        find_package(OpenEXR REQUIRED)
+        set(REQUIRES_Imath TRUE)
         find_package(OpenImageIO REQUIRED)
         add_definitions(-DPXR_OIIO_PLUGIN_ENABLED)
         if (OIIO_idiff_BINARY)
@@ -215,7 +215,7 @@ if (PXR_BUILD_IMAGING)
     if (PXR_ENABLE_VULKAN_SUPPORT)
         if (EXISTS $ENV{VULKAN_SDK})
             # Prioritize the VULKAN_SDK includes and packages before any system
-            # installed headers. This is to prevent linking against older SDKs 
+            # installed headers. This is to prevent linking against older SDKs
             # that may be installed by the OS.
             # XXX This is fixed in cmake 3.18+
             include_directories(BEFORE SYSTEM $ENV{VULKAN_SDK} $ENV{VULKAN_SDK}/include $ENV{VULKAN_SDK}/lib)
@@ -256,7 +256,7 @@ if (PXR_BUILD_IMAGING)
     endif()
     # --OpenVDB
     if (PXR_ENABLE_OPENVDB_SUPPORT)
-        find_package(OpenEXR REQUIRED)
+        set(REQUIRES_Imath TRUE)
         find_package(OpenVDB REQUIRED)
         add_definitions(-DPXR_OPENVDB_SUPPORT_ENABLED)
     endif()
@@ -285,7 +285,7 @@ endif()
 
 if (PXR_BUILD_ALEMBIC_PLUGIN)
     find_package(Alembic REQUIRED)
-    find_package(OpenEXR REQUIRED)
+    set(REQUIRES_Imath TRUE)
     if (PXR_ENABLE_HDF5_SUPPORT)
         find_package(HDF5 REQUIRED
             COMPONENTS
@@ -306,10 +306,19 @@ endif()
 
 if(PXR_ENABLE_OSL_SUPPORT)
     find_package(OSL REQUIRED)
-    find_package(OpenEXR REQUIRED)
+    set(REQUIRES_Imath TRUE)
     add_definitions(-DPXR_OSL_SUPPORT_ENABLED)
 endif()
 
 # ----------------------------------------------
 
+# Try and find Imath or fallback to OpenEXR
+if(REQUIRES_Imath)
+    find_package(Imath)
+    if (NOT Imath_FOUND)
+        MESSAGE(STATUS "Imath not found. Looking for OpenEXR instead.")
+        find_package(OpenEXR REQUIRED)
+    endif()
+endif()
+
 set(BUILD_SHARED_LIBS "${build_shared_libs}")

cmake/modules/FindImath.cmake

@@ -0,0 +1,107 @@
+#
+# Copyright 2022 Apple
+#
+# Licensed under the Apache License, Version 2.0 (the "Apache License")
+# with the following modification; you may not use this file except in
+# compliance with the Apache License and the following modification to it:
+# Section 6. Trademarks. is deleted and replaced with:
+#
+# 6. Trademarks. This License does not grant permission to use the trade
+#    names, trademarks, service marks, or product names of the Licensor
+#    and its affiliates, except as required to comply with Section 4(c) of
+#    the License and to reproduce the content of the NOTICE file.
+#
+# You may obtain a copy of the Apache License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the Apache License with the above modification is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied. See the Apache License for the specific
+# language governing permissions and limitations under the Apache License.
+#
+
+
+# FindImath
+# -------
+#
+# Find Imath include directories and libraries.
+#
+# Input Variables:
+#
+# * Imath_ROOT : The Root location of the built Imath project, where we should look for the headers and dylibs
+# * Imath_USE_DEBUG_BUILD : Use the Debug libraries instead of the release library
+#
+# Output Variables:
+# * FOUND_Imath : Set if the project is found
+# * Imath_LIBRARY | Imath_LIBRARIES : The (list of) Imath libraries
+# * Imath_INCLUDE_DIR | Imath_INCLUDE_DIRS : The location(s) that include the Imath headers
+
+if(NOT DEFINED Imath_USE_DEBUG_BUILD)
+    if(CMAKE_BUILD_TYPE MATCHES "(Debug|DEBUG|debug|RelWithDebInfo|RELWITHDEBINFO|relwithdebinfo)")
+        set(Imath_USE_DEBUG_BUILD TRUE)
+    else()
+        set(Imath_USE_DEBUG_BUILD FALSE)
+    endif()
+endif()
+
+find_path(Imath_INCLUDE_DIR
+        Imath/half.h
+        HINTS
+        "${Imath_LOCATION}"
+        "$ENV{IMATH_LOCATION}"
+        "${Imath_ROOT}"
+        PATH_SUFFIXES
+        include/
+        DOC
+        "Imath headers path"
+        )
+list(APPEND Imath_INCLUDE_DIRS ${Imath_INCLUDE_DIR})
+list(APPEND Imath_INCLUDE_DIRS ${Imath_INCLUDE_DIR}/Imath)
+
+if(Imath_USE_DEBUG_BUILD)
+    find_library(Imath_LIBRARY
+            NAMES
+            Imath-${Imath_MAJOR_VERSION}_${Imath_MINOR_VERSION}_d
+            Imath_d
+            HINTS
+            "${Imath_LOCATION}"
+            "$ENV{Imath_LOCATION}"
+            "${Imath_ROOT}"
+            PATH_SUFFIXES
+            lib/
+            DOC
+            "Imath library path"
+            )
+    if(Imath_LIBRARY)
+        SET(Imath_FOUND TRUE)
+        list(APPEND Imath_LIBRARIES ${Imath_LIBRARY})
+    else()
+        SET(Imath_FOUND FALSE)
+        MESSAGE(WARNING "Could not find Debug Imath library")
+    endif()
+endif()
+
+if (NOT Imath_FOUND)
+    find_library(Imath_LIBRARY
+            NAMES
+            Imath-${Imath_MAJOR_VERSION}_${Imath_MINOR_VERSION}
+            Imath
+            HINTS
+            "${Imath_LOCATION}"
+            "$ENV{Imath_LOCATION}"
+            "${Imath_ROOT}"
+            PATH_SUFFIXES
+            lib/
+            DOC
+            "Imath library path"
+            )
+    if(Imath_LIBRARY)
+        SET(Imath_FOUND TRUE)
+        list(APPEND Imath_LIBRARIES ${Imath_LIBRARY})
+    else()
+        SET(Imath_FOUND FALSE)
+    endif()
+endif()
+

pxr/imaging/hioOpenVDB/CMakeLists.txt

@@ -13,14 +13,20 @@ if (WIN32)
     add_definitions(-D_USE_MATH_DEFINES)
 endif()
 
+if (Imath_FOUND)
+    LIST(APPEND __VDB_IMATH_LIBS ${Imath_LIBRARY})
+else()
+    LIST(APPEND __VDB_IMATH_LIBS ${OPENEXR_Half_LIBRARY})
+endif()
+
 pxr_library(hioOpenVDB
     LIBRARIES
         ar
         gf
         hio
         tf
         usd
-        ${OPENEXR_Half_LIBRARY}
+        ${__VDB_IMATH_LIBS}
         ${OPENVDB_LIBRARY}
 
     INCLUDE_DIRS

pxr/imaging/plugin/hioOiio/CMakeLists.txt

@@ -7,6 +7,14 @@ if (NOT ${PXR_BUILD_GPU_SUPPORT})
     return()
 endif()
 
+if (Imath_FOUND)
+    set(__OIIO_IMATH_INCLUDE ${Imath_INCLUDE_DIRS})
+    set(__OIIO_IMATH_LIBS ${Imath_LIBRARIES})
+else()
+    set(__OIIO_IMATH_INCLUDE ${OPENEXR_INCLUDE_DIRS})
+    set(__OIIO_IMATH_LIBS ${OPENEXR_LIBRARIES})
+endif()
+
 pxr_plugin(hioOiio
     LIBRARIES
         ar
@@ -15,11 +23,11 @@ pxr_plugin(hioOiio
         hio
         tf
         ${OIIO_LIBRARIES}
-        ${OPENEXR_LIBRARIES}
+        ${__OIIO_IMATH_LIBS}
 
     INCLUDE_DIRS
         ${OIIO_INCLUDE_DIRS}
-        ${OPENEXR_INCLUDE_DIRS}
+        ${__OIIO_IMATH_INCLUDE}
 
     CPPFILES
         oiioImage.cpp

pxr/usd/plugin/usdAbc/CMakeLists.txt

@@ -15,6 +15,18 @@ if (PXR_ENABLE_HDF5_SUPPORT)
    list(APPEND optionalIncludeDirs ${HDF5_INCLUDE_DIRS})
 endif()
 
+if (Imath_FOUND)
+    set(__ALEMBIC_IMATH_INCLUDES ${Imath_INCLUDE_DIRS})
+    set(__ALEMBIC_IMATH_LIBS ${Imath_LIBRARIES})
+else()
+    set(__ALEMBIC_IMATH_INCLUDES ${OPENEXR_INCLUDE_DIRS})
+    LIST(APPEND __ALEMBIC_IMATH_LIBS ${OPENEXR_Half_LIBRARY})
+    LIST(APPEND __ALEMBIC_IMATH_LIBS ${OPENEXR_Imath_LIBRARY})
+    LIST(APPEND __ALEMBIC_IMATH_LIBS ${OPENEXR_Iex_LIBRARY})
+    LIST(APPEND __ALEMBIC_IMATH_LIBS ${OPENEXR_IexMath_LIBRARY})
+endif()
+
+
 pxr_plugin(usdAbc
     LIBRARIES
         tf
@@ -23,15 +35,12 @@ pxr_plugin(usdAbc
         usd
         usdGeom
         ${ALEMBIC_LIBRARIES}
-        ${OPENEXR_Half_LIBRARY} 
-        ${OPENEXR_Imath_LIBRARY} 
-        ${OPENEXR_Iex_LIBRARY} 
-        ${OPENEXR_IexMath_LIBRARY}
+        ${__ALEMBIC_IMATH_LIBS}
         ${optionalLibs}
 
     INCLUDE_DIRS
         ${ALEMBIC_INCLUDE_DIR}
-        ${OPENEXR_INCLUDE_DIRS}
+        ${__ALEMBIC_IMATH_INCLUDES}
         ${optionalIncludeDirs}
 
     PRIVATE_CLASSES