Rather than expose the bounding box members directly, we can instead
provide an interface for code to use. This makes it nicer to transition
from global data, as the interface function names are already in
place.
Zero-initialization zeroes out all members and padding bits, so this is
safe to do. While we're at it, also add static assertions that enforce
the necessary requirements of a UID type explicitly within the ShaderUid
class.
This way, we can remove several memset calls around the shader
generation code that makes sure the underlying UID data is zeroed out.
Now our ShaderUid class enforces this for us, so we don't need to care about
it at the usage sites.
Many of the arrays defined within this file weren't declared as
immutable, which can inhibit the strings being put into the read-only
segment. We can declare them constexpr to make them immutable.
While we're at it, we can use std::array, to allow bounds conditional
bounds checking with standard libraries. The declarations can also be
shortened in the future when all platform toolchain versions we use
support std::array deduction guides. Currently macOS and FreeBSD
builders fail on them.
If bounding box is enabled when a UID cache is created, then later disabled,
we shouldn't emit the bounding box portion of the shader.
Fixes pipeline creation errors on D3D12 backend for this case.
The Metal shader compiler fails to compile the atomic instructions
when operating on individual components of a vector. Spltting it
into four variables shouldn't make any difference for other
platforms, as they are accessed independently.
floatindex is clamped to the range [0, 9]. For non-negative numbers
floor() is equivalent to trunc(). Truncation happens implicitly when
converting to uint, so the floor() is unnecessary.
This was causing a warning in the shader compiler, as the rgb components
were not initialized. Which shouldn't be an issue, as the rgb is not
used in the blend equation, only the alpha. However, the lack of
initialization causes crashes in Intel's D3D shader compiler, so we'll
play nice and initialize all the channels.
