Address Nick note, and re-enable CMake build of imaging after bad rebase earlier today

Author: dgovil

cmake/defaults/Options.cmake

@@ -52,10 +52,7 @@ if(APPLE)
             MESSAGE(STATUS "Setting PXR_BUILD_USD_TOOLS=OFF because they are not supported on Apple embedded platforms")
             set(PXR_BUILD_USD_TOOLS OFF)
         endif()
-        if (${PXR_BUILD_IMAGING})
-            MESSAGE(STATUS "Setting PXR_BUILD_USD_IMAGING=OFF because it is not supported on Apple embedded platforms")
-            set(PXR_BUILD_IMAGING OFF)
-        endif ()
+        set(PXR_ENABLE_GL_SUPPORT OFF)
     endif ()
 endif()
 

pxr/imaging/hgiGL/CMakeLists.txt

@@ -1,7 +1,7 @@
 set(PXR_PREFIX pxr/imaging)
 set(PXR_PACKAGE hgiGL)
 
-if (NOT ${PXR_ENABLE_GL_SUPPORT} AND NOT PXR_APPLE_EMBEDDED)
+if (NOT ${PXR_ENABLE_GL_SUPPORT} AND NOT ${PXR_APPLE_EMBEDDED})
     message(STATUS
         "Skipping ${PXR_PACKAGE} because PXR_ENABLE_GL_SUPPORT is OFF")
     return()

pxr/imaging/hgiInterop/metal.h

@@ -9,9 +9,13 @@
 
 #include "pxr/imaging/garch/glApi.h"
 
+
 #include <Metal/Metal.h>
+#if defined(ARCH_OS_OSX)
 #include <AppKit/AppKit.h>
-
+#else
+#include <UIKit/UIKit.h>
+#endif
 #include "pxr/pxr.h"
 #include "pxr/base/gf/vec4i.h"
 #include "pxr/imaging/hgi/texture.h"

pxr/imaging/hgiMetal/texture.mm

@@ -24,11 +24,15 @@
     MTLTextureUsage usage = MTLTextureUsageShaderRead;
 
     if (desc.initialData && desc.pixelsByteSize > 0) {
-#if defined(ARCH_OS_OSX)
-        resourceOptions = MTLResourceStorageModeManaged;
-#else
-        resourceOptions = MTLResourceStorageModeShared;
-#endif
+        #if defined(ARCH_OS_OSX)
+        id<MTLDevice> device = hgi->GetPrimaryDevice();
+        if (![device hasUnifiedMemory]) {
+            resourceOptions = MTLResourceStorageModeManaged;
+        } else
+        #endif
+        {
+            resourceOptions = MTLResourceStorageModeShared;
+        }
     }
 
     MTLPixelFormat mtlFormat = HgiMetalConversions::GetPixelFormat(