On Mon, Jul 3, 2017 at 11:10 AM, Steve Fink <[email protected]> wrote:
> On 07/02/2017 11:20 AM, Lars Hansen wrote: > > On Sun, Jul 2, 2017 at 9:12 AM, J Decker <[email protected]> wrote: > >> >> >> On Sun, Jul 2, 2017 at 8:25 AM, Lars Hansen <[email protected]> wrote: >> >>> The TypedObjects proposal does this, for what it calls non-opaque types >>> (you can define types and then map them onto an ArrayBuffer in various >>> ways). I'm not 100% sure what the latest text is, I expect it is here: >>> https://github.com/tschneidereit/typed-objects-explainer but it could >>> also be here: https://github.com/nikomatsakis/typed-objects-explainer. >>> >>> >> That's about a single structure; as is the thing Isiah suggested >> (ref-struct) and not an array of packed structures such as would be used >> for interleaved vertex data. >> > > No, the TypedObjects proposal allows for packed arrays of structures, > without references. See https://github.com/tschneidereit/typed-objects- > explainer/blob/master/core.md#struct-arrays. > > --lars > >> >> >>> TypedObjects is currently a stalled proposal. I expect it may be >>> revived when WebAssembly integration into JS becomes a more seriously >>> discussed topic. >>> >>> > TypedObjects are exactly what you want for this sort of use case, and are > really quite nice. I'm no expert, but TypedArrays probably ought to be > subsumed by the TypedObject spec since AFAICT they are a proper subset of > TypedObject arrays, at least for practical purposes. > > Yes; I read the proposal more and found that unfortunately the typed objects are padded. https://github.com/tschneidereit/typed-objects-explainer/blob/master/core.md#alignment-and-padding-examples and there's no way to specify unpadded. (although optimal vertex buffers should be arranged so multibyte members are aligned) > Spidermonkey has had them implemented since sometime in 2013, though we > haven't used them much and the constructors are of course not exposed to > the Web. (And the implementation of TypedArrays is still separate, and has > better JIT support.) They're really quite nice when you have the sorts of > problems they're meant for. For other problems, I would guess they would be > quite an attractive nuisance. ;-) > > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > >
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