Module views 

Resource views bound by slot (Views), answering a program’s requests. Where nothing is bound or an address falls outside a view, they answer as their policy states (Absent): as Direct3D answers (Absent::Zero, the rules below), or by refusing, naming the slot or address (Absent::Refuse: an evaluation runs on no value it was not given). The rules are the D3D11.3 functional specification’s, stated here once:

• Nothing bound. A sample from a slot with no texture bound returns 0 in all components (7.18.17), and so does a load (“Fetching from t# that has nothing bound to it returns 0 for all components”, 22.4.6), a structured read (22.4.12) and a size query (22.4.14, resinfo). A buffer at an empty slot has no elements.
• Out of range. A load whose address or level is outside the view returns 0 in all components (22.4.6’s out-of-bounds behaviour; every view here has all four components, so no missing-component default arises), a typed buffer’s element past its end too, and a structured read of an element past the end returns 0 (22.4.12). A structured read whose byte offset is past its element is undefined there (22.4.12) and refused here.
• Sampling. A view holds one level, so every level of detail reads it; a sample is filtered as its sampler slot states (ViewSampler): the texel it falls in, or linear between the texels about it (four in 2D, eight in a volume), each axis addressed (a border reads the slot’s border colour; a border with none is refused). A sampler slot nothing states is refused, never assumed. An image the caller samples itself (View::Image) is sampled by its own policy at the level of detail the program states.

What a view is not asked for is refused by name: a gather, a comparison, a texel offset, a cube or 1D texture, a layer other than 0 of a 2D view (any layer of a caller’s image), a multisample or unordered-access load, a store or an atomic (their effect is the caller’s).

Structs

ViewSampler

A sampler slot’s state: its filter, the addressing along u, v and w, and the colour a border reads.

Views

The views and sampler states bound by slot, and what a request reads where they hold nothing (see the module documentation). A program reads them through &Views (the views are only read, so one table serves every thread).

Enums

Absent

What a request reads where the views hold nothing for it: a slot nothing is bound to, or an address or level outside its view (a structured read’s byte offset past its element is refused either way).

View

One bound view.

ViewFilter

How a sampler slot filters a view.

Traits

Image

A texture the caller samples itself (its footprint, addressing, filtering and transfer are its own policy), by the level of detail the program states (crate::Lod).