Description: Update FindOpenEXR from blender.
 This version properly handles OpenEXR3
 https://developer.blender.org/diffusion/B/browse/master/build_files/cmake/Modules/FindOpenEXR.cmake
Author: Andreas Metzler <ametzler@debian.org>
Bug-Debian: https://bugs.debian.org/1023997
Origin: vendor
Forwarded: https://sourceforge.net/p/pfstools/bugs/54/
Last-Update: 2022-11-15

--- a/cmake/FindOpenEXR.cmake
+++ b/cmake/FindOpenEXR.cmake
@@ -1,5 +1,8 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright 2011 Blender Foundation.
+
 # - Find OpenEXR library
 # Find the native OpenEXR includes and library
 # This module defines
 #  OPENEXR_INCLUDE_DIRS, where to find ImfXdr.h, etc. Set when
 #                        OPENEXR_INCLUDE_DIR is found.
@@ -16,108 +19,191 @@
 #  OPENEXR_IMATH_LIBRARY, Path to Imath library
 #
 # also defined, but not for general use are
 #  OPENEXR_LIBRARY, where to find the OpenEXR library.
 
-#=============================================================================
-# Copyright 2011 Blender Foundation.
-#
-# Distributed under the OSI-approved BSD License (the "License");
-# see accompanying file Copyright.txt for details.
-#
-# This software is distributed WITHOUT ANY WARRANTY; without even the
-# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-# See the License for more information.
-#=============================================================================
-
 # If OPENEXR_ROOT_DIR was defined in the environment, use it.
 IF(NOT OPENEXR_ROOT_DIR AND NOT $ENV{OPENEXR_ROOT_DIR} STREQUAL "")
   SET(OPENEXR_ROOT_DIR $ENV{OPENEXR_ROOT_DIR})
 ENDIF()
 
-SET(_openexr_FIND_COMPONENTS
-  Half
-  Iex
-  IlmImf
-  IlmThread
-  Imath
-)
-
+# Old versions (before 2.0?) do not have any version string,
+# just assuming this should be fine though.
+SET(_openexr_libs_ver_init "2.0")
 
 SET(_openexr_SEARCH_DIRS
   ${OPENEXR_ROOT_DIR}
-  /usr/local
-  /sw # Fink
-  /opt/local # DarwinPorts
-  /opt/csw # Blastwave
-  "C:/Program Files (x86)/OpenEXR" # Windows
+  /opt/lib/openexr
 )
 
 FIND_PATH(OPENEXR_INCLUDE_DIR
   NAMES
-    ImfXdr.h
+    OpenEXR/ImfXdr.h
   HINTS
     ${_openexr_SEARCH_DIRS}
   PATH_SUFFIXES
-    include/OpenEXR include
+    include
 )
 
-#message( "Include dir: ${OPENEXR_INCLUDE_DIR}" )
+# If the headers were found, get the version from config file, if not already set.
+IF(OPENEXR_INCLUDE_DIR)
+  IF(NOT OPENEXR_VERSION)
+
+    FIND_FILE(_openexr_CONFIG
+      NAMES
+        OpenEXRConfig.h
+      PATHS
+        "${OPENEXR_INCLUDE_DIR}"
+        "${OPENEXR_INCLUDE_DIR}/OpenEXR"
+      NO_DEFAULT_PATH
+    )
+
+    IF(_openexr_CONFIG)
+      FILE(STRINGS "${_openexr_CONFIG}" OPENEXR_BUILD_SPECIFICATION
+           REGEX "^[ \t]*#define[ \t]+OPENEXR_VERSION_STRING[ \t]+\"[.0-9]+\".*$")
+    ELSE()
+      MESSAGE(WARNING "Could not find \"OpenEXRConfig.h\" in \"${OPENEXR_INCLUDE_DIR}\"")
+    ENDIF()
+
+    IF(OPENEXR_BUILD_SPECIFICATION)
+      MESSAGE(STATUS "${OPENEXR_BUILD_SPECIFICATION}")
+      STRING(REGEX REPLACE ".*#define[ \t]+OPENEXR_VERSION_STRING[ \t]+\"([.0-9]+)\".*"
+             "\\1" _openexr_libs_ver_init ${OPENEXR_BUILD_SPECIFICATION})
+    ELSE()
+      MESSAGE(WARNING "Could not determine ILMBase library version, assuming ${_openexr_libs_ver_init}.")
+    ENDIF()
+
+    UNSET(_openexr_CONFIG CACHE)
+
+  ENDIF()
+ENDIF()
+
+SET("OPENEXR_VERSION" ${_openexr_libs_ver_init} CACHE STRING "Version of OpenEXR lib")
+UNSET(_openexr_libs_ver_init)
+
+STRING(REGEX REPLACE "([0-9]+)[.]([0-9]+).*" "\\1_\\2" _openexr_libs_ver ${OPENEXR_VERSION})
+
+# Different library names in 3.0, and Imath and Half moved out.
+IF(OPENEXR_VERSION VERSION_GREATER_EQUAL "3.0.0")
+  SET(_openexr_FIND_COMPONENTS
+    Iex
+    OpenEXR
+    OpenEXRCore
+    IlmThread
+  )
+ELSE()
+  SET(_openexr_FIND_COMPONENTS
+    Half
+    Iex
+    IlmImf
+    IlmThread
+    Imath
+  )
+ENDIF()
 
 SET(_openexr_LIBRARIES)
 FOREACH(COMPONENT ${_openexr_FIND_COMPONENTS})
   STRING(TOUPPER ${COMPONENT} UPPERCOMPONENT)
 
   FIND_LIBRARY(OPENEXR_${UPPERCOMPONENT}_LIBRARY
     NAMES
-      ${COMPONENT}-2_2 ${COMPONENT}-2.2 ${COMPONENT}-2.1 ${COMPONENT}-2_1 ${COMPONENT}  # The newest version first
+      ${COMPONENT}-${_openexr_libs_ver} ${COMPONENT}
+    NAMES_PER_DIR
     HINTS
       ${_openexr_SEARCH_DIRS}
     PATH_SUFFIXES
       lib64 lib
     )
+  LIST(APPEND _openexr_LIBRARIES "${OPENEXR_${UPPERCOMPONENT}_LIBRARY}")
+ENDFOREACH()
 
-#  message( "Lib: ${OPENEXR_${UPPERCOMPONENT}_LIBRARY}" )
+UNSET(_openexr_libs_ver)
 
-#  IF( NOT "${OPENEXR_${UPPERCOMPONENT}_LIBRARY}" )
-#	message( "Library ${COMPONENT} not found" )
-#	SET( OPENEXR_FOUND "" )
-#	break()
-#  ENDIF()
-	
-  LIST(APPEND _openexr_LIBRARIES OPENEXR_${UPPERCOMPONENT}_LIBRARY)
-  
-ENDFOREACH()
+IF(OPENEXR_VERSION VERSION_GREATER_EQUAL "3.0.0")
+  # For OpenEXR 3.x, we also need to find the now separate Imath library.
+  # For simplicity we add it to the OpenEXR includes and libraries, as we
+  # have no direct dependency on Imath and it's simpler to support both
+  # 2.x and 3.x this way.
 
-# OpenEXR needs zlib, which could be tricky to locate on Windows
-# You may need to manually do something like this:
-#SET(ZLIB_DIR "e:/zlib/")
-#SET(CMAKE_INCLUDE_PATH ${ZLIB_DIR}/include ${CMAKE_INCLUDE_PATH})
-#SET(CMAKE_LIBRARY_PATH ${ZLIB_DIR}/ ${ZLIB_DIR}/lib ${CMAKE_LIBRARY_PATH})
+  # Find include directory
+  FIND_PATH(IMATH_INCLUDE_DIR
+    NAMES
+      Imath/ImathMath.h
+    HINTS
+      ${_openexr_SEARCH_DIRS}
+    PATH_SUFFIXES
+      include
+  )
+
+  # Find version
+  FIND_FILE(_imath_config
+    NAMES
+      ImathConfig.h
+    PATHS
+      ${IMATH_INCLUDE_DIR}/Imath
+    NO_DEFAULT_PATH
+  )
+
+  # Find line with version, extract string, and format for library suffix.
+  FILE(STRINGS "${_imath_config}" _imath_build_specification
+       REGEX "^[ \t]*#define[ \t]+IMATH_VERSION_STRING[ \t]+\"[.0-9]+\".*$")
+  STRING(REGEX REPLACE ".*#define[ \t]+IMATH_VERSION_STRING[ \t]+\"([.0-9]+)\".*"
+         "\\1" _imath_libs_ver ${_imath_build_specification})
+  STRING(REGEX REPLACE "([0-9]+)[.]([0-9]+).*" "\\1_\\2" _imath_libs_ver ${_imath_libs_ver})
+
+  # Find library, with or without version number.
+  FIND_LIBRARY(IMATH_LIBRARY
+    NAMES
+      Imath-${_imath_libs_ver} Imath
+    NAMES_PER_DIR
+    HINTS
+      ${_openexr_SEARCH_DIRS}
+    PATH_SUFFIXES
+      lib64 lib
+    )
+  LIST(APPEND _openexr_LIBRARIES "${IMATH_LIBRARY}")
 
-FIND_PACKAGE(ZLIB REQUIRED)
-LIST(APPEND _openexr_LIBRARIES ZLIB_LIBRARY)
+  # In cmake version 3.21 and up, we can instead use the NO_CACHE option for
+  # FIND_FILE so we don't need to clear it from the cache here.
+  UNSET(_imath_config CACHE)
+  UNSET(_imath_libs_ver)
+  UNSET(_imath_build_specification)
+ENDIF()
 
-# handle the QUIETLY and REQUIRED arguments and set OPENEXR_FOUND to TRUE if 
+# handle the QUIETLY and REQUIRED arguments and set OPENEXR_FOUND to TRUE if
 # all listed variables are TRUE
 INCLUDE(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(OpenEXR  DEFAULT_MSG
+    _openexr_LIBRARIES OPENEXR_INCLUDE_DIR)
 
-#FIND_PACKAGE_HANDLE_STANDARD_ARGS(OpenEXR  DEFAULT_MSG  
-#    ${_openexr_LIBRARIES} OPENEXR_INCLUDE_DIR)	
-
-#  message( "${_openexr_LIBRARIES}" )
-  
-# This is a work-around as passing the list does not work in cmake 2.8.11.2 (cygwin)  
-FIND_PACKAGE_HANDLE_STANDARD_ARGS(OpenEXR  DEFAULT_MSG  
-    OPENEXR_HALF_LIBRARY OPENEXR_IEX_LIBRARY OPENEXR_ILMIMF_LIBRARY OPENEXR_ILMTHREAD_LIBRARY OPENEXR_IMATH_LIBRARY ZLIB_LIBRARY OPENEXR_INCLUDE_DIR)
- 	
 IF(OPENEXR_FOUND)
-  SET(OPENEXR_LIBRARIES ${OPENEXR_ILMTHREAD_LIBRARY} ${OPENEXR_IEX_LIBRARY} ${OPENEXR_ILMIMF_LIBRARY} ${OPENEXR_IMATH_LIBRARY} ${OPENEXR_HALF_LIBRARY} ${ZLIB_LIBRARY})
-  # Both include paths are needed because of dummy OSL headers mixing #include <OpenEXR/foo.h> and #include <foo.h> :(
-  SET(OPENEXR_INCLUDE_DIRS ${OPENEXR_INCLUDE_DIR} ${OPENEXR_INCLUDE_DIR}/OpenEXR ${ZLIB_INCLUDE_DIR})
+  SET(OPENEXR_LIBRARIES ${_openexr_LIBRARIES})
+  # Both include paths are needed because of dummy OSL headers mixing
+  # #include <OpenEXR/foo.h> and #include <foo.h>, as well as Alembic
+  # include <half.h> directly.
+  SET(OPENEXR_INCLUDE_DIRS
+    ${OPENEXR_INCLUDE_DIR}
+    ${OPENEXR_INCLUDE_DIR}/OpenEXR)
+
+  IF(OPENEXR_VERSION VERSION_GREATER_EQUAL "3.0.0")
+    LIST(APPEND OPENEXR_INCLUDE_DIRS
+      ${IMATH_INCLUDE_DIR}
+      ${IMATH_INCLUDE_DIR}/Imath)
+  ENDIF()
 ENDIF()
 
-MARK_AS_ADVANCED(OPENEXR_INCLUDE_DIR)
+MARK_AS_ADVANCED(
+  OPENEXR_INCLUDE_DIR
+  OPENEXR_VERSION
+  IMATH_INCLUDE_DIR
+  IMATH_LIBRARY
+)
 FOREACH(COMPONENT ${_openexr_FIND_COMPONENTS})
   STRING(TOUPPER ${COMPONENT} UPPERCOMPONENT)
   MARK_AS_ADVANCED(OPENEXR_${UPPERCOMPONENT}_LIBRARY)
 ENDFOREACH()
+
+UNSET(COMPONENT)
+UNSET(UPPERCOMPONENT)
+UNSET(_openexr_FIND_COMPONENTS)
+UNSET(_openexr_LIBRARIES)
+UNSET(_openexr_SEARCH_DIRS)