Function getSizeAndAlignmentOfUnsizedArrayElement

Returns the size, align, and unalignedSize of "the" unsized array element. Unsized arrays are only allowed at the outer most level or the last member of a top level struct.

Example:

const code = `
struct Foo {
  a: u32,
  b: array<vec3f>,
};
@group(0) @binding(0) var<storage> f: Foo;
`;
const defs = makeShaderDataDefinitions(code);
const { size, align, unalignedSize } = getSizeAndAlignmentOfUnsizedArrayElement(
   defs.storages.f);
// size = 16   (since you need to allocate 16 bytes per element)
// align = 16  (since vec3f needs to be aligned to 16 bytes)
// unalignedSize = 12 (since only 12 bytes are used for a vec3f)
Copy

Generally you only need size. Example:

const code = `
struct Foo {
  a: u32,
  b: array<vec3f>,
};
@group(0) @binding(0) var<storage> f: Foo;
`;
const defs = makeShaderDataDefinitions(code);
const { size } = getSizeAndAlignmentOfUnsizedArrayElement(defs.storages.f);
const numElements = 10;
const views = makeStructuredViews(
   defs.storages.f,
   new ArrayBuffer(defs.storages.f.size + size * numElements));
Copy