| // Copyright (c) 2016-2020 NVIDIA Corporation |
| // |
| // SPDX-License-Identifier: CC-BY-4.0 |
| |
| include::{generated}/meta/{refprefix}VK_NV_external_memory.txt[] |
| |
| === Other Extension Metadata |
| |
| *Last Modified Date*:: |
| 2016-08-19 |
| *IP Status*:: |
| No known IP claims. |
| *Contributors*:: |
| - James Jones, NVIDIA |
| - Carsten Rohde, NVIDIA |
| |
| === Description |
| |
| Applications may wish to export memory to other Vulkan instances or other |
| APIs, or import memory from other Vulkan instances or other APIs to enable |
| Vulkan workloads to be split up across application module, process, or API |
| boundaries. |
| This extension enables applications to create exportable Vulkan memory |
| objects such that the underlying resources can be referenced outside the |
| Vulkan instance that created them. |
| |
| include::{generated}/interfaces/VK_NV_external_memory.txt[] |
| |
| === Issues |
| |
| 1) If memory objects are shared between processes and APIs, is this |
| considered aliasing according to the rules outlined in the |
| <<resources-memory-aliasing,Memory Aliasing>> section? |
| |
| *RESOLVED*: Yes, but strict exceptions to the rules are added to allow some |
| forms of aliasing in these cases. |
| Further, other extensions may build upon these new aliasing rules to define |
| specific support usage within Vulkan for imported native memory objects, or |
| memory objects from other APIs. |
| |
| 2) Are new image layouts or metadata required to specify image layouts and |
| layout transitions compatible with non-Vulkan APIs, or with other instances |
| of the same Vulkan driver? |
| |
| *RESOLVED*: No. |
| Separate instances of the same Vulkan driver running on the same GPU should |
| have identical internal layout semantics, so applictions have the tools they |
| need to ensure views of images are consistent between the two instances. |
| Other APIs will fall into two categories: Those that are Vulkan compatible |
| (a term to be defined by subsequent interopability extensions), or Vulkan |
| incompatible. |
| When sharing images with Vulkan incompatible APIs, the Vulkan image must be |
| transitioned to the ename:VK_IMAGE_LAYOUT_GENERAL layout before handing it |
| off to the external API. |
| |
| Note this does not attempt to address cross-device transitions, nor |
| transitions to engines on the same device which are not visible within the |
| Vulkan API. |
| Both of these are beyond the scope of this extension. |
| |
| === Examples |
| |
| [source,c++] |
| ---------------------------------------- |
| |
| // TODO: Write some sample code here. |
| |
| ---------------------------------------- |
| |
| === Version History |
| |
| * Revision 1, 2016-08-19 (James Jones) |
| - Initial draft |
