* Most of the main entry points that can fail with relevant reasons now has a
way of specifying a message to return with it. This message can be displayed
to the user to give more information or context about an error.
* This is a stupid requirement as the quad overdraw shader doesn't use any
interpolators, but the D3D12 runtime complains and refuses to create a PSO
unless the PS has a matching signature. This works as long as the position was
the first output from the previous stage, but if it isn't the PSO fails to
create.
* To fix this, we take the existing shader and patch it by grafting the output
signature from the last stage over onto the input signature, and patching up
where the position is.
* There's not a good accepted terminology for this kind of event, and for
historical reasons 'drawcall' has been the accepted term, even though
that can be quite confusing when a dispatch or a copy is a 'drawcall'.
* This is particularly highlighted by the event browser filters where
$draw() includes draws and dispatches, but $dispatch() only includes
dispatches, it's hard to intuitively understand why $draw() matches all
of these calls.
* As a result we've defined the term 'action' to cover these types of
events in the same way that we defined 'event' in the first place to
mean a single atomic API call.
* When displaying mip 0 of a texture at less than 100% zoom we linear sampling,
but we don't want to linear sample across slices. Adding a half pixel offset
in z ensures we sample precisely on the slice itself.
* These map more naturally to python tuples and are easier to wrap in and out.
* We also tidy up the FloatVecVal etc and standardise the members of
ShaderValue.
* Pixel picking is a bottleneck, so do a render to a headless output and read
that back as a way of quickly checking that all of the subresource is OK at
once.
* We need to copy the external-facing m_RenderState into the partial command
buffer's state for partial replay, in case it was modified externally.
* Also when accessing the render state inside a drawcall callback we need to use
the command buffer's local state, not m_RenderState which isn't updated until
the replay completes.
* This helps catches cases where a discarded image is accidentally used and in
many cases may still have valid data. Particularly on Vulkan this is relevant
for DONT_CARE renderpass load and store ops.
* This is a leftover artifact from before we had general extended type support
and double was the only non-32 bit type we handled. Now we support most type
formats so doubles are just CompType::Float with 8 byte width
* E.g. on D3D12 we can debug DXBC shaders but not DXIL shaders. On vulkan this
will allow us to have the UI work better when encountering shaders with
unsupported capabilities or extensions.
baldurk