BindEntry

Syntax

interface BindEntry {
  readonly group: number;
  readonly binding: number;
  readonly name: string;
  readonly space: AddressSpace;
  readonly access?: 'read' | 'read_write';
  readonly resourceKind: ResourceKind;
  readonly owner: 'module' | 'host';
  readonly glslSpelling?: 'std140-block' | 'loose';
  readonly structName?: string;
  readonly textureDim?: '2d' | '2d-ms' | '2d-array' | 'cube' | '3d' | '1d' | 'cube-array';
  readonly textureElem?: TextureElem;
  readonly sampleType?: 'float' | 'unfilterable-float' | 'depth' | 'sint' | 'uint';
  readonly storageFormat?: StorageTextureFormat;
  readonly storageAccess?: 'write-only' | 'read-only' | 'read-write';
  readonly textureDepth?: true;
  readonly samplerComparison?: true;
  readonly stages: readonly ('vertex' | 'fragment' | 'compute')[];
}

Description

name is the declaration’s own identifier, the one shader code reads through (field_view.foo). A GLSL host binding a struct binding needs structName instead: GLSL’s block syntax is layout(std140) uniform <StructName> { … } <name>;, so getUniformBlockIndex takes the struct’s type name ('FieldView' for a binding named field_view). Passing name there does not fail to link; the block silently lands at GL’s default binding point 0 and aliases whatever else is bound there.

group and binding are metadata only on the GLSL backend. The emitted GLSL carries no binding qualifier, so a GLSL host resolves every entry by name at link time and assigns the binding point or texture unit itself from these numbers. GLSL has one flat namespace and no group, so a host whose modules declare more than one group folds group into the point it assigns (group * 8 + binding, say) so that two groups’ binding 0 do not collide.

Instance properties

groupread only number

bindingread only number

nameread only string

spaceread only AddressSpace

accessoptionalread only 'read' | 'read_write'

resourceKindread only ResourceKind

ownerread only 'module' | 'host'

Who owns the resource. 'module' when the module declares it and the host builds its bind group from this reflection; 'host' when the surrounding host owns it and the host’s own layout is the authority. Always set. bindGroups lists host-owned bindings too: a host still has to know about a binding it owns, it just must not allocate for it.

glslSpellingoptionalread only 'std140-block' | 'loose'

How GLSL ES 3.00 spells a host-owned struct binding. Present only when owner is 'host' and the binding’s type is a struct: a module-owned block is always a std140 block, and WGSL has one spelling regardless. 'std140-block' means bind a uniform buffer to the block index; 'loose' means the members were flattened into the default uniform block and are set individually with glUniform* under their field names (the layout in uniforms still lists them, in declaration order).

structNameoptionalread only string

The struct’s type name, for a binding whose type is a struct; absent on every other kind. It is the name a GLSL host passes to getUniformBlockIndex.

textureDimoptionalread only '2d' | '2d-ms' | '2d-array' | 'cube' | '3d' | '1d' | 'cube-array'

The texture dimension the shader declared, so a host can create or validate the matching view: '2d-array' needs an array view and a layer-aware bind, '2d-ms' a multisampled one, 'cube' a cube view, '3d' a 3d one, '1d' a 1d one and 'cube-array' a cube-array view — the value GPUTextureViewDescriptor.dimension takes. Always set on a texture entry, absent on every other kind.

textureElemoptionalread only TextureElem

The texel element the shader declared. Always set on a texture entry, absent on every other kind.

A host needs both textureDim and textureElem to build a valid binding, since the dimension alone does not say whether the view is float or integer. WebGPU’s GPUTextureBindingLayout.sampleType must be 'uint' or 'sint' for a u32 or i32 texture and one of the two float types for f32; WebGL2 must back an integer texture with an integer internal format (R32UI, R32I). The value is the DSL’s own element, untranslated, because reflection takes a module and never a backend.

An integer texture is unfilterable, so a host must not pair one with a filtering sampler. A module that type-checks never asks it to: textureSample rejects an integer texture at compile time.

BindEntry.sampleType is what a layout takes for it, from this element and the calls that read the texture.

sampleTypeoptionalread only 'float' | 'unfilterable-float' | 'depth' | 'sint' | 'uint'

What a host’s GPUTextureBindingLayout.sampleType takes for this texture, in WebGPU’s own words, from the element the shader declared and the calls that read it. Always set on a texture entry, absent on every other kind, so a host never has to read absence as a default.

• 'depth' for a depth texture;
• 'uint' or 'sint' for a u32 or an i32 texture;
• 'float' for an f32 texture that a call pairs with a sampler: a textureSample (any of its forms) or a textureGather in an entry or in a function an entry calls, through a helper’s parameters or a const of the texture as well. A sampler binding is laid out filtering, which WebGPU refuses beside an unfilterable texture, and a 'float' layout takes a filterable format only;
• 'unfilterable-float' for every other f32 texture: one the entries load, measure or count and never sample, one no entry reaches, and a multisampled one, which no sampler reads. It takes every format a 'float' layout takes, and the 32-bit float formats (r32float, rgba32float) that layout refuses.

A module with a raw statement in what its entries reach is opaque, so each of its f32 textures but a multisampled one is 'float'. A module with no entry is read whole, since a host writes the entries over it. The sample type follows the texture, not one entry: a texture that one entry samples and another loads is 'float' for both.

A host that samples an unfilterable format through a non-filtering sampler, which a module cannot say, writes its own layout for that binding.

storageFormatoptionalread only StorageTextureFormat

The texel format the shader declared for a storage texture, exactly as WebGPU’s GPUStorageTextureBindingLayout.format spells it. Always set on a storage-texture entry, absent on every other kind (roadmap 0.4 item 10).

A storage texture’s format is part of its type in WGSL, not a property of the view, and a host’s bind group layout has to repeat it exactly: a layout whose format differs from the shader’s is a validation error at pipeline creation.

storageAccessoptionalread only 'write-only' | 'read-only' | 'read-write'

How the shader may touch a storage texture, in WebGPU’s spelling rather than WGSL’s — 'write-only', 'read-only', 'read-write' — which is what GPUStorageTextureBindingLayout.access takes. Always set on a storage-texture entry, absent on every other kind.

A host passing WGSL’s own write / read / read_write through gets a validation error, so the translation happens here rather than in every host.

textureDepthoptionalread only true

Set on a depth texture (roadmap 0.4 item 11): the host’s GPUTextureBindingLayout takes sampleType: 'depth' for it, which BindEntry.sampleType reports, and pairs it with a comparison sampler. Always true on such an entry, absent on every other kind, so a host never has to read absence as “not depth” on an entry that is not a texture at all. A depth texture has no textureElem.

samplerComparisonoptionalread only true

Set on a comparison sampler (roadmap 0.4 item 11): the host’s GPUSamplerBindingLayout takes type: 'comparison' for it. Always true on such an entry, absent otherwise.

stagesread only readonly ('vertex' | 'fragment' | 'compute')[]

The stages that reference this binding, in the order vertex, fragment, compute. It comes from the same reachability walk the per-stage GLSL emit uses to decide which shader declares which uniform, so a host’s stage mask can never describe a narrower program than the emit produces. It is GPUBindGroupLayoutEntry.visibility before it becomes a bitmask, and the same fact a WebGL2 host uses to assign uniform-block binding points and texture units per stage. It is a list so that compute is expressible alongside vertex and fragment.

Always set, and it can be empty. bindGroups lists every declared binding, so a binding no entry point reaches (declared and never read, or in a module with no entry point at all) reports []. A host must not invent a visibility for it.

For a host-owned binding (owner: 'host') this is the module’s view and therefore a lower bound: the host’s real layout may expose the resource to stages this module’s entries never reach. Merge it into the host layout; do not narrow the host layout to it.

See also

• textureSample

Source

src/core/reflect.ts, line 341, at commit 26de7be8