Enum PhaseItemExtraIndex

pub enum PhaseItemExtraIndex {
    None,
    DynamicOffset(u32),
    IndirectParametersIndex {
        range: Range<u32>,
        batch_set_index: Option<NonMaxU32>,
    },
}

The “extra index” associated with some PhaseItems, alongside the indirect instance index.

Sometimes phase items require another index in addition to the range of instances they already have. These can be:

• The dynamic offset: a wgpu dynamic offset into the uniform buffer of instance data. This is used on platforms that don’t support storage buffers, to work around uniform buffer size limitations.

• The indirect parameters index: an index into the buffer that specifies the indirect parameters for this PhaseItem’s drawcall. This is used when indirect mode is on (as used for GPU culling).

Note that our indirect draw functionality requires storage buffers, so it’s impossible to have both a dynamic offset and an indirect parameters index. This convenient fact allows us to pack both indices into a single u32.

Variants

None

No extra index is present.

DynamicOffset(u32)

A wgpu dynamic offset into the uniform buffer of instance data. This is used on platforms that don’t support storage buffers, to work around uniform buffer size limitations.

IndirectParametersIndex

An index into the buffer that specifies the indirect parameters for this PhaseItem’s drawcall. This is used when indirect mode is on (as used for GPU culling).

Fields

range: Range<u32>

The range of indirect parameters within the indirect parameters array.

If we’re using multi_draw_indirect_count, this specifies the maximum range of indirect parameters within that array. If batches are ultimately culled out on the GPU, the actual number of draw commands might be lower than the length of this range.

batch_set_index: Option<NonMaxU32>

If multi_draw_indirect_count is in use, and this phase item is part of a batch set, specifies the index of the batch set that this phase item is a part of.

If multi_draw_indirect_count isn’t in use, or this phase item isn’t part of a batch set, this is None.

Implementations

impl PhaseItemExtraIndex

pub fn maybe_indirect_parameters_index( indirect_parameters_index: Option<NonMaxU32>, ) -> PhaseItemExtraIndex

Returns either an indirect parameters index or PhaseItemExtraIndex::None, as appropriate.

pub fn maybe_dynamic_offset( dynamic_offset: Option<NonMaxU32>, ) -> PhaseItemExtraIndex

Returns either a dynamic offset index or PhaseItemExtraIndex::None, as appropriate.

Trait Implementations

impl Clone for PhaseItemExtraIndex

fn clone(&self) -> PhaseItemExtraIndex

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for PhaseItemExtraIndex

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for PhaseItemExtraIndex

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for PhaseItemExtraIndex

fn eq(&self, other: &PhaseItemExtraIndex) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for PhaseItemExtraIndex

impl StructuralPartialEq for PhaseItemExtraIndex