Vulkan: MoltenVK Support for Developers

MoltenVK original intent was to let developers work on a mac system developing
for the vulkan eco-system. MoltenVK doesn't support all the features that we
require and would require additional workarounds to be actually supported.

It is not expected that we will release Blender with MoltenVK for this reason.
But it still has value for shader developers to validate shaders on metal and
vulkan on a single platform.

![image](/attachments/9a4a9904-a5f6-4922-896d-744dfb78244c)

Pull Request: https://projects.blender.org/blender/blender/pulls/117940

CMakeLists.txt

@@ -870,19 +870,29 @@ else()
 endif()
 
 # Vulkan
-if(NOT APPLE)
-  option(WITH_VULKAN_BACKEND "Enable Vulkan as graphics backend (experimental)" ON)
-  option(WITH_VULKAN_GUARDEDALLOC "\
-Use guardedalloc for host allocations done inside Vulkan (development option)"
+option(WITH_VULKAN_BACKEND "Enable Vulkan as graphics backend (experimental)" ON)
+option(WITH_VULKAN_GUARDEDALLOC "Use guardedalloc for host allocations done inside Vulkan (development option)"
   OFF
-  )
-  mark_as_advanced(
+)
+mark_as_advanced(
   WITH_VULKAN_BACKEND
   WITH_VULKAN_GUARDEDALLOC
+)
+if(APPLE)
+  option(WITH_VULKAN_MOLTENVK "Enable Vulkan over MoltenVK (development option)" OFF)
+  mark_as_advanced(
+    WITH_VULKAN_MOLTENVK
   )
-  if(NOT WITH_EXPERIMENTAL_FEATURES)
+endif()
+
+if(APPLE AND NOT WITH_VULKAN_MOLTENVK)
   set(WITH_VULKAN_BACKEND OFF)
+endif()
+if(NOT WITH_EXPERIMENTAL_FEATURES)
+  if (APPLE)
+    set(WITH_VULKAN_MOLTENVK OFF)
   endif()
+  set(WITH_VULKAN_BACKEND OFF)
 endif()
 
 # Metal

build_files/cmake/Modules/FindMoltenVK.cmake

@@ -43,11 +43,11 @@ find_path(MOLTENVK_INCLUDE_DIR
 
 find_library(MOLTENVK_LIBRARY
   NAMES
-    MoltenVK
+    libMoltenVK.dylib
   HINTS
     ${_moltenvk_SEARCH_DIRS}
   PATH_SUFFIXES
-    dylib/macOS
+    dynamic/dylib/macOS
 )
 
 # handle the QUIETLY and REQUIRED arguments and set MOLTENVK_FOUND to TRUE if

build_files/cmake/platform/platform_apple.cmake

@@ -108,6 +108,12 @@ if(WITH_OPENSUBDIV)
 endif()
 add_bundled_libraries(opensubdiv/lib)
 
+if(WITH_VULKAN_BACKEND)
+  find_package(MoltenVK REQUIRED)
+  find_package(ShaderC REQUIRED)
+  find_package(Vulkan REQUIRED)
+endif()
+
 if(WITH_CODEC_SNDFILE)
   find_package(SndFile)
   find_library(_sndfile_FLAC_LIBRARY NAMES flac HINTS ${LIBDIR}/sndfile/lib)

intern/ghost/intern/GHOST_ContextVK.cc

@@ -32,10 +32,6 @@
 
 #include <sys/stat.h>
 
-/* Set to 0 to allow devices that do not have the required features.
- * This allows development on OSX until we really needs these features. */
-#define STRICT_REQUIREMENTS true
-
 /*
  * Should we only select surfaces that are known to be compatible. Or should we in case no
  * compatible surfaces have been found select the first one.
@@ -226,14 +222,15 @@ class GHOST_DeviceVK {
     queue_create_infos.push_back(graphic_queue_create_info);
 
     VkPhysicalDeviceFeatures device_features = {};
-#if STRICT_REQUIREMENTS
+#ifndef __APPLE__
     device_features.geometryShader = VK_TRUE;
-    device_features.dualSrcBlend = VK_TRUE;
+    /* MoltenVK supports logicOp, needs to be build with MVK_USE_METAL_PRIVATE_API. */
     device_features.logicOp = VK_TRUE;
+#endif
+    device_features.dualSrcBlend = VK_TRUE;
     device_features.imageCubeArray = VK_TRUE;
     device_features.multiViewport = VK_TRUE;
     device_features.shaderClipDistance = VK_TRUE;
-#endif
     device_features.drawIndirectFirstInstance = VK_TRUE;
     device_features.fragmentStoresAndAtomics = VK_TRUE;
     device_features.samplerAnisotropy = features.features.samplerAnisotropy;
@@ -355,7 +352,11 @@ static GHOST_TSuccess ensure_vulkan_device(VkInstance vk_instance,
       }
     }
 
-#if STRICT_REQUIREMENTS
+#ifdef __APPLE__
+    if (!device_vk.features.features.dualSrcBlend || !device_vk.features.features.imageCubeArray) {
+      continue;
+    }
+#else
     if (!device_vk.features.features.geometryShader || !device_vk.features.features.dualSrcBlend ||
         !device_vk.features.features.logicOp || !device_vk.features.features.imageCubeArray)
     {
@@ -1000,8 +1001,7 @@ GHOST_TSuccess GHOST_ContextVK::initializeDrawingContext()
 
   if (use_window_surface) {
     const char *native_surface_extension_name = getPlatformSpecificSurfaceExtension();
-
-    requireExtension(extensions_available, extensions_enabled, "VK_KHR_surface");
+    requireExtension(extensions_available, extensions_enabled, VK_KHR_SURFACE_EXTENSION_NAME);
     requireExtension(extensions_available, extensions_enabled, native_surface_extension_name);
 
     extensions_device.push_back(VK_KHR_SWAPCHAIN_EXTENSION_NAME);
@@ -1010,10 +1010,13 @@ GHOST_TSuccess GHOST_ContextVK::initializeDrawingContext()
   extensions_device.push_back(VK_KHR_GET_MEMORY_REQUIREMENTS_2_EXTENSION_NAME);
 
   /* Enable MoltenVK required instance extensions. */
-#ifdef VK_MVK_MOLTENVK_EXTENSION_NAME
+#ifdef __APPLE__
   requireExtension(
-      extensions_available, extensions_enabled, "VK_KHR_get_physical_device_properties2");
+      extensions_available, extensions_enabled, VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME);
 #endif
+  requireExtension(extensions_available,
+                   extensions_enabled,
+                   VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2_EXTENSION_NAME);
 
   VkInstance instance = VK_NULL_HANDLE;
   if (!vulkan_device.has_value()) {
@@ -1046,6 +1049,10 @@ GHOST_TSuccess GHOST_ContextVK::initializeDrawingContext()
       create_info.pNext = &validationFeatures;
     }
 
+#ifdef __APPLE__
+    create_info.flags |= VK_INSTANCE_CREATE_ENUMERATE_PORTABILITY_BIT_KHR;
+#endif
+
     VK_CHECK(vkCreateInstance(&create_info, nullptr, &instance));
   }
   else {

source/blender/gpu/vulkan/vk_backend.cc

@@ -103,7 +103,9 @@ void VKBackend::detect_workarounds(VKDevice &device)
       !device.physical_device_vulkan_12_features_get().shaderOutputViewportIndex;
 
   /* AMD GPUs don't support texture formats that use are aligned to 24 or 48 bits. */
-  if (GPU_type_matches(GPU_DEVICE_ATI, GPU_OS_ANY, GPU_DRIVER_ANY)) {
+  if (GPU_type_matches(GPU_DEVICE_ATI, GPU_OS_ANY, GPU_DRIVER_ANY) ||
+      GPU_type_matches(GPU_DEVICE_APPLE, GPU_OS_MAC, GPU_DRIVER_ANY))
+  {
     workarounds.not_aligned_pixel_formats = true;
   }
 

source/creator/creator_args.cc

@@ -1400,15 +1400,15 @@ static const char arg_handle_gpu_backend_set_doc[] =
     "\tForce to use a specific GPU backend. Valid options: "
 #  ifdef WITH_OPENGL_BACKEND
     "'opengl'"
-#    if defined(WITH_VULKAN_BACKEND)
-    " or "
-#    endif
-#  endif
-#  ifdef WITH_VULKAN_BACKEND
-    "'vulkan' (experimental)"
 #  endif
 #  ifdef WITH_METAL_BACKEND
     "'metal'"
+#  endif
+#  ifdef WITH_VULKAN_BACKEND
+#    if defined(WITH_OPENGL_BACKEND) || defined(WITH_METAL_BACKEND)
+    " or "
+#    endif
+    "'vulkan' (experimental)"
 #  endif
     ".";
 static int arg_handle_gpu_backend_set(int argc, const char **argv, void * /*data*/)