tree 2ab30a1fa31c82d78f4e802a8c7fbc0682175cce
parent 0e0ea0265bf8faa41adda42e45a728924bd1bad8
author Gregg Tavares <gman@chromium.org> 1660936283 -0700
committer Angle LUCI CQ <angle-scoped@luci-project-accounts.iam.gserviceaccount.com> 1666051751 +0000

Metal: Optimized BufferSubData per device

Adds a staging buffer path which means there are 4 paths
for bufferSubData.

1. direct copy

   * get a pointer to the buffer
   * copy the new data to the buffer
   * if the buffer is managed, tell metal which part was updated

2. use a shadow copy

   * copy the data to a shadow copy
   * copy the entire shadow to a new buffer
   * start using the new buffer

3. use a new buffer

   * get a new buffer (or unused)
   * put the new data in the new buffer
   * blit any unchanged data from the old buffer to the new buffer
   * start using the new buffer

4. use a staging buffer

   * get a staging buffer
   * put the new data in the staging buffer
   * blit from the staging buffer to the existing buffer.

Further, there are 3 types of memory storage modes.
Managed, Staged, Private.

Based on the GPU type different storage modes and different
paths in different sitatutions are more performant.

So, add feature flags to select paths by GPU.

Bug: angleproject:7544
Change-Id: I741dd1874201043416374194bd2001ded8dbd9b4
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3842641
Reviewed-by: Kyle Piddington <kpiddington@apple.com>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Reviewed-by: Quyen Le <lehoangquyen@chromium.org>
Commit-Queue: Gregg Tavares <gman@chromium.org>