It worked ok on Vulkan but is causing problems on DX12 and Metal. Punt
for now and come back to this later when we do more sophisticated
resource management.
Move types into the toplevel and hide implementation details. Remove
deref of hub CmdBuf to mux. Restrict public visibility of internals.
Most items have some docs, though improvements are still possible. In
particular, there should be detailed safety info.
This gets a swapchain displayed and fills out a number of the image
related parts of the API: image creation, binding to descriptor sets,
and blitting.
Add workgroup size to dispatch call (needed by metal). Change all fence
references to mutable for consistency.
Move backend traits to a separate file (move them out of the toplevel
namespace in preparation for the hub types going there, to make the
public API nicer).
Add a method and macro for automatically choosing shader code, and
change collatz example to generate all 3 kinds on build.
A bunch of loose ends remain, including needing to plumb the size of the
workgroup through. Image and swapchains also need to be added. But it
does run collatz.
Progress towards #95.
Change the interface for fences to accept mutable references. This will
actualy help the Metal backend more than dx12 (avoiding interior
mutability) but more accurately captures intent and matches gfx-hal.
Make the hub abstraction connect to the mux, rather than directly to the
Vulkan back-end.
As of this commit, both command line and winit examples work (on
Vulkan). In theory it should be possible to get them working on Dx12 as
well by translating the shader code, but there's a lot that can go
wrong.
This commit also contains a bunch of changes to mux to make conditional
compilation of match arms work, and new methods to support swapchain.
Adds a new "mux" module which can have multiple backends. As of this
commit, it's not wired up at all, but the functionality should be
reasonably complete.
Minor tweaks to the backend trait to accommodate this, mostly changing
Fence and Semaphore to references so they don't need to be Copy.
Part of the work toward #95
Use an enum instead of Box<dyn Any> for resources to be retained until
command buffer completion, and allow both references (which will be
cloned) and owned resources (useful for staging buffers).
Add a method to create a buffer with initial content, which requires
staging buffers under the hood.
This patch also changes the lower-level (Vulkan) interface to be closer
to the raw Vulkan call.
