With this the backend ignores explicit usage transition hints from the
frontent and generates all the barriers automatically based on resource
usage.
The current implementation is very naive and encodes a barrier
immediately just before a resource is used in a new state.
With this commit the Vulkan backend completely ignores the explicit
barrier commands passed from the frontend, and generates its own
pipeline barriers.
Right now it encodes each barrier just before the resources are used,
which is quite bad but will be optimized later.
This commit also makes the frontend command buffer validation perform
the checks necessary for implicit barriers (although they are redundant
with checks for explicit barriers) because the tracking can pre-compute
pass usage information that's useful for the Vulkan backend.
Tests for usage validation inside passes will be added once the concept
of transition is removed from the API.
Making all textures represented by pointers is a problem for Vulkan
where VkImage is a 64bit type and wouldn't fit in a pointer on 32bit
builds. Make texture contain on of each useful type so that each backend
can choose which one it wants to receive.
Adds the swap chain interfaces to the API without changing the behavior
of anything else. This includes the C APIs for applications to provide
swap chain implementations. Also adds stub implementations on every
backend.
Corentin Wallez
Kai Ninomiya