VulkanHub
Enum

VkExternalMemoryFeatureFlagBits

Bitmask specifying features of an external memory handle type

Bits which may be set in VkExternalMemoryProperties::externalMemoryFeatures, specifying features of an external memory handle type, are:

typedef enum VkExternalMemoryFeatureFlagBits {
    VK_EXTERNAL_MEMORY_FEATURE_DEDICATED_ONLY_BIT = 0x00000001,
    VK_EXTERNAL_MEMORY_FEATURE_EXPORTABLE_BIT = 0x00000002,
    VK_EXTERNAL_MEMORY_FEATURE_IMPORTABLE_BIT = 0x00000004,
} VkExternalMemoryFeatureFlagBits;

or the equivalent

#define VkExternalMemoryFeatureFlagBitsKHR VkExternalMemoryFeatureFlagBits
  • VK_EXTERNAL_MEMORY_FEATURE_DEDICATED_ONLY_BIT specifies that images or buffers created with the specified parameters and handle type must use the mechanisms defined by VkMemoryDedicatedRequirements and VkMemoryDedicatedAllocateInfo to create (or import) a dedicated allocation for the image or buffer.
  • VK_EXTERNAL_MEMORY_FEATURE_EXPORTABLE_BIT specifies that handles of this type can be exported from Vulkan memory objects.
  • VK_EXTERNAL_MEMORY_FEATURE_IMPORTABLE_BIT specifies that handles of this type can be imported as Vulkan memory objects.

Because their semantics in external APIs roughly align with that of an image or buffer with a dedicated allocation in Vulkan, implementations are required to report VK_EXTERNAL_MEMORY_FEATURE_DEDICATED_ONLY_BIT for the following external handle types:

  • VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_TEXTURE_BIT
  • VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_TEXTURE_KMT_BIT
  • VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D12_RESOURCE_BIT
  • VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID for images only
  • VK_EXTERNAL_MEMORY_HANDLE_TYPE_SCREEN_BUFFER_BIT_QNX for images only
  • VK_EXTERNAL_MEMORY_HANDLE_TYPE_MTLTEXTURE_BIT_EXT

Implementations must not report VK_EXTERNAL_MEMORY_FEATURE_DEDICATED_ONLY_BIT for buffers with external handle type VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID. Implementations must not report VK_EXTERNAL_MEMORY_FEATURE_DEDICATED_ONLY_BIT for buffers with external handle type VK_EXTERNAL_MEMORY_HANDLE_TYPE_SCREEN_BUFFER_BIT_QNX. Implementations must not report VK_EXTERNAL_MEMORY_FEATURE_DEDICATED_ONLY_BIT for images or buffers with external handle type VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_ALLOCATION_BIT_EXT, or VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_MAPPED_FOREIGN_MEMORY_BIT_EXT.