Move EMotionFX's OpenGL dependency to 3rd Party and make sure Mac builds successfully

Gems/EMotionFX/Code/CMakeLists.txt

@@ -68,12 +68,6 @@ ly_add_target(
 )
 
 if (PAL_TRAIT_BUILD_HOST_TOOLS)
-
-    find_package(OpenGL QUIET REQUIRED)
-    # Imported targets (like OpenGL::GL) are scoped to a directory. Add a
-    # a global scope
-    add_library(3rdParty::OpenGLInterface INTERFACE IMPORTED GLOBAL)
-    target_link_libraries(3rdParty::OpenGLInterface INTERFACE OpenGL::GL)
     
     ly_add_target(
         NAME EMotionFX.Editor.Static STATIC

Gems/EMotionFX/Code/Editor/Platform/Mac/platform_mac.cmake

@@ -13,10 +13,4 @@
 # based on the active platform
 # NOTE: functions in cmake are global, therefore adding functions to this file
 # is being avoided to prevent overriding functions declared in other targets platfrom
-# specific cmake files
-
-target_compile_definitions(3rdParty::OpenGLInterface
-    INTERFACE
-        # MacOS 10.14 deprecates OpenGL. This silences the warnings for now.
-        GL_SILENCE_DEPRECATION
-)
+# specific cmake files

cmake/3rdParty/FindOpenGLInterface.cmake

@@ -0,0 +1,21 @@
+#
+# All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
+# its licensors.
+#
+# For complete copyright and license terms please see the LICENSE at the root of this
+# distribution (the "License"). All use of this software is governed by the License,
+# or, if provided, by the license below or the license accompanying this file. Do not
+# remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#
+
+find_package(OpenGL QUIET REQUIRED)
+# Imported targets (like OpenGL::GL) are scoped to a directory. Add a
+# a global scope
+add_library(3rdParty::OpenGLInterface INTERFACE IMPORTED GLOBAL)
+target_link_libraries(3rdParty::OpenGLInterface INTERFACE OpenGL::GL)
+
+set(pal_file ${CMAKE_CURRENT_LIST_DIR}/Platform/${PAL_PLATFORM_NAME}/OpenGLInterface_${PAL_PLATFORM_NAME_LOWERCASE}.cmake)
+if(EXISTS ${pal_file})
+    include(${pal_file})
+endif()

cmake/3rdParty/Platform/Mac/OpenGLInterface_mac.cmake

@@ -0,0 +1,16 @@
+#
+# All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
+# its licensors.
+#
+# For complete copyright and license terms please see the LICENSE at the root of this
+# distribution (the "License"). All use of this software is governed by the License,
+# or, if provided, by the license below or the license accompanying this file. Do not
+# remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#
+
+target_compile_definitions(3rdParty::OpenGLInterface
+    INTERFACE
+        # MacOS 10.14 deprecates OpenGL. This silences the warnings for now.
+        GL_SILENCE_DEPRECATION
+)

cmake/3rdParty/Platform/Mac/cmake_mac_files.cmake

@@ -15,6 +15,7 @@ set(FILES
     Clang_mac.cmake
     DirectXShaderCompiler_mac.cmake
     FbxSdk_mac.cmake
+    OpenGLInterface_mac.cmake
     OpenSSL_mac.cmake
     Wwise_mac.cmake
 )

cmake/3rdParty/cmake_files.cmake

@@ -18,6 +18,7 @@ set(FILES
     Finddyad.cmake
     FindFbxSdk.cmake
     Findlibav.cmake
+    FindOpenGLInterface.cmake
     FindOpenSSL.cmake
     FindRadTelemetry.cmake
     FindVkValidation.cmake