Struct SceneTextureId

Source

pub struct SceneTextureId(/* private fields */);

Expand description

A process-unique id Texture::as_scene_texture mints once per Texture and shares across Clone — the TextureRegistry key Command::SceneTexture resolves against.

Mirrors frust_scene::ShaderProgram::id: minted fresh only at construction (never re-minted on Clone), off a process-wide AtomicU64 so two distinct textures never collide even when built on different threads.

Implementations§

Source §

impl SceneTextureId

Source

pub fn mint() -> Self

Mints a fresh, process-unique id.

Texture::new mints one per texture and shares it across Clone, and that stays the ordinary route. This is public for the caller that has no Texture to mint from: a texture rendered externally — one whose wgpu::TextureView its owner creates, re-creates and binds itself every frame — still needs one stable id to be named by across those re-creations, and minting here is what hands it one out of the same process-wide counter. The shader-program and texture-source id spaces stay reserved against every such mint by construction (see Self::for_shader_program and Self::for_texture_source).

§Panics

After 2^62 - 1 mints, rather than handing out an id inside a reserved namespace — a count no process reaches.

Source

pub const fn for_shader_program(program_id: u64) -> Self

The id under which the offscreen target of the fragment program program_id is registered.

Derived from the program’s own ordinal rather than minted, because both halves of the seam have to name the same texture while holding different things: the pre-pass that renders the program has the target, and the display-list walk that draws it has only frust_scene::ShaderProgram::id. A pure function of the program id lets each compute the id the other used, with no shared side table to keep in step.

Disjoint from Self::mint’s range and from Self::for_texture_source’s by construction — see [SHADER_PROGRAM_NAMESPACE] — so a host texture, a texture source and a shader target can never answer to the same id. A program_id large enough to reach a reserved bit itself is impossible for the same counting reason its minter is.

Source

pub const fn for_texture_source(source: u64) -> Self

The id under which the external-texture frame bus registers its source-th frame source.

Derived from an ordinal the bus counts itself rather than minted, for the same reason Self::for_shader_program is: the namespace is the bus’s own, so an ordinary external pass can be refused an id inside it and a bus registration can never displace one a caller minted. The ordinal is masked below both reserved bits before the namespace bit is set, so the result is never a shader-program id either — disjoint from Self::mint and Self::for_shader_program by construction (see [SHADER_PROGRAM_NAMESPACE]).

Source

pub const fn get(self) -> u64

The opaque value this id wraps.

The counterpart of frust_scene::ShaderProgram::id, and for the same reason: the scene layer carries an externally owned texture as a plain u64 so it depends on no GPU crate, and a caller that registered a Texture needs some way to say which one a display-list command means. This only reads back what Self::mint handed out; it never mints.

Source

pub const fn is_shader_program(self) -> bool

Whether self carries the bit Self::for_shader_program sets — i.e. whether it names a shader program’s own offscreen target rather than something an ordinary caller minted.

Lets a caller outside this module test which namespace an id belongs to without the reserved bit itself being exported — a check on the id stays valid even if the bit’s exact value ever changed.

Source

pub const fn is_texture_source(self) -> bool

Whether self names a texture-bus frame source (Self::for_texture_source) rather than something an ordinary caller minted or a shader program’s target.

The namespace counterpart of Self::is_shader_program, for the same reason: a registry that must refuse the bus’s ids to anyone but the bus tests membership without the reserved bit being exported.