Rename IMATH_REPO/TAG to OPENEXR_IMATH_REPO/TAG and update install docs

For consistency with ``OPENEXR_DEFLATE_REPO`` and other config options.

Also, add docs section for the ``DEFLATE`` options.

Signed-off-by: Cary Phillips <[email protected]>

cmake/OpenEXRSetup.cmake

@@ -226,9 +226,9 @@ endif()
 
 option(OPENEXR_FORCE_INTERNAL_IMATH "Force using an internal imath" OFF)
 # Check to see if Imath is installed outside of the current build directory.
-set(IMATH_REPO "https://github.com/AcademySoftwareFoundation/Imath.git" CACHE STRING
+set(OPENEXR_IMATH_REPO "https://github.com/AcademySoftwareFoundation/Imath.git" CACHE STRING
     "Repo for auto-build of Imath")
-set(IMATH_TAG "main" CACHE STRING
+set(OPENEXR_IMATH_TAG "main" CACHE STRING
   "Tag for auto-build of Imath (branch, tag, or SHA)")
 if(NOT OPENEXR_FORCE_INTERNAL_IMATH)
   #TODO: ^^ Release should not clone from main, this is a place holder
@@ -239,14 +239,14 @@ endif()
 
 if(NOT TARGET Imath::Imath AND NOT Imath_FOUND)
   if(OPENEXR_FORCE_INTERNAL_IMATH)
-    message(STATUS "Imath forced internal, installing from ${IMATH_REPO} (${IMATH_TAG})")
+    message(STATUS "Imath forced internal, installing from ${OPENEXR_IMATH_REPO} (${OPENEXR_IMATH_TAG})")
   else()
-    message(STATUS "Imath was not found, installing from ${IMATH_REPO} (${IMATH_TAG})")
+    message(STATUS "Imath was not found, installing from ${OPENEXR_IMATH_REPO} (${OPENEXR_IMATH_TAG})")
   endif()
   include(FetchContent)
   FetchContent_Declare(Imath
-    GIT_REPOSITORY "${IMATH_REPO}"
-    GIT_TAG "${IMATH_TAG}"
+    GIT_REPOSITORY "${OPENEXR_IMATH_REPO}"
+    GIT_TAG "${OPENEXR_IMATH_TAG}"
     GIT_SHALLOW ON
       )
 

docs/install.rst

@@ -284,9 +284,9 @@ Imath Dependency
 
 * ``CMAKE_PREFIX_PATH``
 
-  The standard CMake path in which to
-  search for dependencies, Imath in particular.  A comma-separated
-  path. Add the root directory where Imath is installed.
+  The standard CMake path in which to search for dependencies, Imath
+  in particular.  A comma-separated path. Add the root directory where
+  Imath is installed.
 
 * ``Imath_DIR``
 
@@ -296,6 +296,45 @@ Imath Dependency
   file, which is typically the ``lib/cmake/Imath`` folder of the root
   install directory.
 
+* ``OPENEXR_IMATH_REPO`` and ``OPENEXR_IMATH_TAG``
+
+  The github Imath repo to auto-fetch if an installed library cannot
+  be found, and the tag to sync it to.  The default repo is
+  ``https://github.com/AcademySoftwareFoundation/Imath.git`` and the
+  tag is specific to the OpenEXR release. The internal build is
+  configured as a CMake subproject.
+
+* ``OPENEXR_FORCE_INTERNAL_IMATH``
+
+  If set to ``ON``, force auto-fetching and internal building of Imath
+  using ``OPENEXR_IMATH_REPO`` and ``OPENEXR_IMATH_TAG``. This means
+  do *not* use any existing installation of Imath.
+
+libdeflate Dependency
+~~~~~~~~~~~~~~~~~~~~~
+
+As of OpenEXR release v3.2, OpenEXR depends on 
+`libdeflate <https://github.com/ebiggers/libdeflate>`_ for
+DEFLATE-based compression. Previous OpenEXR releases relied on `zlib
+<https://www.zlib.net>`_. Builds of OpenEXR can choose either an
+libdeflat installation, or CMake can auto-fetch the source and build it
+internally. The internal build is linked statically, so no extra
+shared object is produced.
+
+* ``OPENEXR_DEFLATE_REPO`` and ``OPENEXR_DEFLATE_TAG``
+
+  The github Imath repo to auto-fetch if an installed library cannot
+  be found, and the tag to sync it to. The default repo is
+  ``https://github.com/ebiggers/libdeflate.git`` and the tag is
+  ``v1.18``. The internal build is configured as a CMake subproject.
+
+* ``OPENEXR_FORCE_INTERNAL_DEFLATE``
+
+  If set to ``ON``, force auto-fetching and internal building of
+  ``libdeflate`` using ``OPENEXR_DEFLATE_REPO`` and
+  ``OPENEXR_DEFLATE_TAG``. This means do *not* use any existing
+  installation of ``libdeflate``.
+
 Namespace Options
 ~~~~~~~~~~~~~~~~~