Weak refs don't quite work here correctly as there is always a race with
taking the lock between find_view() and remove_view(). If find_view()
returns a view that is going to removed by remove_view() then we have an
interesting situation.
In theory, the number and type of views for an image are relatively
constant and should not change one they've been set up which means that
it is actually practical to perform pool-like reference counting here
where the image holds a pool of different views that it can give out
as necessary.
The major functionality gain this provides is proper reference counting
for a descriptor set. Overall this allows us to create descriptor sets
when they are needed (or reused from a cache) without violating any of
vulkan's object synchronisation requirements.
As there are a fixed number of sets available in a pool, the number of
descriptors in elements is currently hardcoded to 32. This can be extended
in a future change to create pools on the fly if that limit is ever overrun.
Allows a cleaner control flow when there is no fence available for use
with the trash list. An always signalled fence type will always return
TRUE for gst_vulkan_fence_is_signalled.
Serve two purposes:
1. refcounting of vulkan handles with associated destruction. When
combined with the trash list, the user can ensure destruction at
the correct time according to the vulkan rules.
2. avoids polluting our API with 32-bit vs 64-bit integer/pointers
differences as exposed through the vulkan API. on 32-bit, vulkan
non-dispatchable handles are 64-bit integers and on 64-bit, they
are pointers.
By passing NULL to `g_signal_new` instead of a marshaller, GLib will
actually internally optimize the signal (if the marshaller is available
in GLib itself) by also setting the valist marshaller. This makes the
signal emission a bit more performant than the regular marshalling,
which still needs to box into `GValue` and call libffi in case of a
generic marshaller.
Note that for custom marshallers, one would use
`g_signal_set_va_marshaller()` with the valist marshaller instead.
* Fix meson build script for Windows. Since the Vulkan dependency
object was declared by us in case of Windows, the dependency object
shouldn't be used for finding header
* Fix build error by including Windows specific header
gstvkdisplay.c(563): error C2065: 'VK_KHR_WIN32_SURFACE_EXTENSION_NAME': undeclared identifier
1. The iOS create_surface implementation needs to call out to the main
thread to create the window (UIKit requirement)
2. get_surface() can be called and will attempt to create the VkSurface
from an invalid view/layer.
Also pass the layer for MoltenVK so we don't get pesky 'UIView function
not called on main thread' warnings.
During resizes, the VkQueuePresent can return OUT_OF_DATE and if a buffer
is displayed returning OUT_OF_DATE it would error out and stop the pipeline.
We already have a explicit check for OUT_OF_DATE and the same general
error check in the statements following so just use that code.
