This adds several fields to `ExternalTextureDescriptor`, specifying
how to handle color space conversion for an external texture. These
fields consist of transfer functions for the source and destination
color spaces, and a matrix for converting between gamuts. This allows
`ImageSample` and `ImageLoad` operations on external textures to
return values in a desired destination color space rather than the
source color space of the underlying planes.
These fields are plumbed through to the `ExternalTextureParams`
uniform buffer from which they are exposed to the shader. Following
conversion from YUV to RGB after sampling/loading from the external
texture planes, the shader uses them to gamma decode to linear RGB in
the source color space, convert from source to destination gamut, then
finally gamma encode to non-linear RGB in the destination color space.
During wgsl lowering, if we encounter an external texture type then
generate the `ExternalTextureParams` struct. This will be required by
most Naga backends to implement external textures.
This type is not actually used by wgsl-in or the IR. However,
generating it in Naga IR ensures tricky details such as member
alignment are handled for us.
wgsl-out must ensure it does *not* generate code for this type, as it
handles external textures natively.
Adds a mode to compaction that removes unused functions, global
variables, and named types and overrides. This mode is used
everywhere except the compaction at the end of lowering, where
it is important to preserve unused items for type checking and
other validation of the module.
Pruning all but the active entry point and then compacting makes
`process_overrides` tolerant of missing values for overrides that are
not used by the active entry point.
Fixes#5885
* [wgsl-in,ir] add support for parsing rust-style doc comments
* rename relevant items to `doc_comments` (or variations of it)
* address comments
* remove `next_until`
* rename `save_doc_comments` to `ignore_doc_comments`
* expand snapshot test and ignore blankspace when accumulating doc comments
* make tokenizer more straightforward
---------
Co-authored-by: teoxoy <28601907+teoxoy@users.noreply.github.com>
When the user provides values for a module's overrides, rather than
replacing override-sized array types with ordinary array types (which
could require adjusting type handles throughout the module), instead
edit all overrides to have initializers that are fully-evaluated
constant expressions. Then, change all backends to handle
override-sized arrays by retrieving their overrides' values.
For arrays whose sizes are override expressions, not simple references
to a specific override's value, let front ends built array types that
refer to anonymous overrides whose initializers are the necessary
expression.
This means that all arrays whose sizes are override expressions are
references to some `Override`. Remove `naga::PendingArraySize`, and
let `ArraySize::Pending` hold a `Handle<Override>` in all cases.
Expand `tests/gpu-tests/shader/array_size_overrides.rs` to include the
test case that motivated this approach.
Define `TypeInner::is_abstract`, and let it take a type arena so that
it can properly handle abstract arrays. Use this in compaction and in
the WGSL front end's conversion code to recognize abstract types.
Instead allow the const to be converted and each time it is const
evaluated as part of another expression. This allows an abstract const
to be used as a different type depending on the context.
A consequence of this is that abstract types may now find their way to
the validation stage, which we don't want. We therefore additionally
now ensure that the compact pass removes global constants of abstract
types. This will have no *functional* effect on shaders generated by
the backends, as the expressions belonging to the abstract consts in
the IR will not actually be used, as any usage in the input shader
will have been const-evaluated away. Certain unused const declarations
will now be removed, however, as can be seen by the effect on the
snapshot outputs.
Ensure that unnamed constants' types are retained, even when the
constants are used only by global expressions. Add a test case.
The old code marked all named constants as used; then processed
function bodies; and then marked the types of all used constants as
used. This ensured that, as long as a constant was used by a function,
its type would be retained, but didn't address the case where a
constant is used only by a global expression.
In compaction, remove unused anonymous overrides.
Since overrides are no longer used by definition, include override
initialization expressions in the tandem traversal of types and global
expressions.
To simplify overload processing, we plan to make all override-sized
arrays refer to their lengths via actual `Override`s. Arrays with
non-identifier override expressions as their lengths would refer to
anonymous `Override`s with interesting `init` expressions. But in
order to avoid re-introducing #6788, we need compaction to remove
anonymous overrides.
Rather than reversing two iterators and then zipping them, zip them
first and then reverse the result.
However, zipped iterators are only reversible if the inputs implement
`ExactSizeIterator`, so make `UniqueArena::iter` promise that as well.
For consistency, make `Arena::iter` also promise to return an
`ExactSizeIterator`.
In compaction, correctly identify unused types and global expressions,
rather than treating all global expressions referred to by
`PendingArraySize::Expression` array lengths as used even if the array
type itself is not.
This is tested by checking that going from expression to type and
back, along with the opposite, is correctly marked as used. It also
checks that adding an unused type using an expression gets compacted
out.
See the comments on `ModuleTracer::type_expression_tandem` for
details.
Fixes#6788.
Adjust the `Handle<Expression>` values that appear in
`TypeInner::Array` via `PendingArraySize::Expression` as part of the
normal type adjustment process in `ModuleMap::adjust_type`, rather
than cloning the type arena so we can iterate over it and call
`UniqueArena::replace`.
Fixes#6789.
Have `compact::compact` preserve entries in the `Module::types` arena
if they have names.
Future abstract type support will require the WGSL front end to
compact the module before validation. Without this change, that will
drop `alias` declarations, making it harder to test type validation.
Identify reachable function expressions, constant expressions, and
types using a single pass over each arena, taking advantage of the
fact that expressions and types may only refer to other entries that
precede them within their arena. Only walking the statement tree still
requires a worklist/recursion.
In addition to presumably being faster, this change slightly reduces
the number of non-comment lines of code in `src/compact`.
