This was way more pain that initially expected, especially in regards to
preserving externally-specified pNext chains without writing to them in
any way.
After I implemented the render pass wrapper, seeing how the
RenderPassCreateInfo structure and its dependencies were HUGE compared
to the actual tiny and lean RenderPass, I felt uneasy dragging their
definition along to every place where a RenderPass gets used. It's not
as bad with the others, but as new extensions are implemented I expect
that to get the same.
This change makes it easier for me to accept that Image.h / Buffer.h
depends on Memory.h. There isn't a real measurable difference when
building Magnum itself (50 ms out of 7 seconds for the Vk library
alone), but that's because most of the code (and tests) needs the
CreateInfo structures anyway.
More convenient to use since one doesn't have to explicitly store a
DeviceProperties instance to call pickQueueFamily() on it and then move
it to DeviceCreateInfo to keep it efficient.
This required a slight redesign of how DeviceProperties are stored in
DeviceCreateInfo, now we need the instance to be always valid (but it
can get never used). The wrap() API isn't doing any extra work so this
won't add any inefficiency.
Today I spent six hours wrongly convincing myself that it's a driver bug
when vkGetPhysicalDeviceProperties2() is null on a 1.1 instance for a
1.0 physical device. It's not a bug, it's me not reading specs
carefully.
This commit thus basically moves all Instance-level extension-dependent
state to DeviceProperties, because it's actually device-dependent. Which
makes the DeviceProperties class quite heavy and thus it's good it was
readied to be transferred all the way to a Device instance a few commits
back -- I don't really want to do all the dispatch, string processing,
sorting and other mess more times than strictly necessary.
In addition, DeviceProperties::apiVersion() got renamed to version() and
a new isVersionSupported() API got added, mirroring what's on Device
itself; plus thanks to the chicken-and-egg problem of having to call
vkGetPhysicalDeviceProperties() twice, the device version and other
things can now be retrieved in a slightly more efficient way.
I have more and more cases where I need to query device properties later
down the road (memory capabilities, device name, ...) and leaving all
this up to the user / making this impossible to do in the library
internals is complicating everything too much.
Since there's a shitton of device properties with a new bag of props
coming with every other new extension, I expect the queries to get quite
involved / complicated over time (chaining 100s structs and such), so
let's design this upfront in a way that can avoid reqpeatedly querying
the same thing just because we needlessly discarded a fully populated
instance before.
It also means the users don't need to drag their own DeviceProperties
instance along anymore and can just let the Device take care of that.
Unfortunately the only nice way to make this work with DeviceCreateInfo
method chaining is to add & and && overloads for each. But it's quite
easy to test that all of them work and properly return a r-value
reference so it shouldn't be too much of a maintenance nightmare.
It's there only to create the instance right now. Not using it to test
instance-level functionality right now as we'd be only working around it
anyway.
Vladimír Vondruš