tree 3e7cd9df4021564c5f3f82a87206dde6196af134
parent 4abc4d45e7deced6bd4942798a47b5ec256e4d86
author Chip Davis <cdavis@codeweavers.com> 1565196439 -0500
committer Chip Davis <cdavis@codeweavers.com> 1565365483 -0500

Use placement heaps for VkDeviceMemory when possible.

All Apple GPUs support this, as does Mac GPU family 2. With this, we can
avoid expensive copies between buffers and textures allocated from the
same memory, and reduce memory usage to boot.

macOS is, unfortunately, constrained by the fact that `MTLHeap` objects
do not support any storage mode other than `MTLStorageModePrivate`--not
even `MTLStorageModeManaged`. This won't help for managed textures
there. Perhaps Apple will fix this in a later version.