Cannot access ANGLE_instanced_arrays or other extensions

[ZacLiveEarth]

I'm trying to use WebGL extensions within web_sys, but cannot seem to access the ANGLE_instanced_arrays interface that exists in this webidl - https://github.com/rustwasm/wasm-bindgen/blob/master/crates/web-sys/webidls/enabled/WebGLRenderingContext.webidl

Here is what I've tried...
let ext = context.get_extension("ANGLE_instanced_arrays").unwrap().unwrap();
let inst_arrays = ext.dyn_into::<web_sys::ANGLE_instanced_arrays>();

I've opened a related StackOverflow question here: but wasn't sure that would get your attention.

Apologies if this is something obvious, today is my first day writing Rust.

[chinedufn]

Congrats on your first day with Rust!

So I have some example code that uses OES_vertex_array_object. Your use case should be similar

---

I get the extension here:

https://github.com/chinedufn/webgl-water-tutorial/blob/master/src/render/mod.rs#L52-L55

---

extension is stored as a js_sys::Object

https://github.com/chinedufn/webgl-water-tutorial/blob/master/src/render/mod.rs#L29

---

Then you can use Reflect::get to call methods on it

https://github.com/chinedufn/webgl-water-tutorial/blob/master/src/render/mod.rs#L219

---

Does that work for you?

[ZacLiveEarth]

Yes, that looks like it will work thanks for the help.

Are there any performance concerns with using Reflect and allocating an array each time there?

Is exposing a more idiomatic interface something that I could help out with? I would be willing to create a PR, but some pointing in the right direction would probably be necessary.

[chinedufn]

In practice I doubt that it would matter much for most use cases but if it did could just store the Array in a struct or somewhere and then re-use the same Array each time.

---

So I'm not sure if the WebGL extensions are specified in WebIDL (I doubt it but not sure).

If they are then web-sys could probably be made to auto generate the bindings but that's outside of my knowledge about the crate so I can't offer any help here - sorry!

\cc @fitzgen

[ZacLiveEarth]

So I'm not sure if the WebGL extensions are specified in WebIDL (I doubt it but not sure).

interface ANGLE_instanced_arrays { is at line 1063

[chinedufn]

Ohhh sweet looks like there are a bunch of extensions in there! Cool let's wait on word from someone who knows why they weren't originally included!

[alexcrichton]

I think that's currently skipped due to this check where NoInterfaceObject means that we skip generating bindings. I think nowadays though it may be possible to test out removing that check and see how far we get! @ZacLiveEarth would you be up for poking around in the webidl generator to see if that can be removed to solve this issue?

[ZacLiveEarth]

@alexcrichton Yes, I will take a look this afternoon. Do you have a contributor guidelines page, or a getting started contributing for the build process, etc?

[alexcrichton]

We do indeed! It all starts here

[ZacLiveEarth]

Was starting by doing some research into what this attribute means, and found out that there's a PR to remove [NoInterfaceObject] from webidl entirely - whatwg/webidl#609

[ZacLiveEarth]

Got a bit stuck. Here are some of the things I've done...

Removed the is_no_interface_object check. Building with cargo build -vv before this check clearly showed the log for skipping the interfaces that I'm interested in, including ANGLE_instanced_arrays. Building after does not show those log lines, and does not introduce any new lines that are concerning.

Here is the relevant output:

[web-sys 0.3.14] cargo:rerun-if-env-changed=__WASM_BINDGEN_DUMP_FEATURES
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL Maplike interface member: AudioParamMap Maplike(MaplikeInterfaceMember { attributes: None, readonly: Some(ReadOnly), maplike: Maplike, generics: Generics { open_angle: LessThan, body: (AttributedType { attributes: None, type_: Single(NonAny(DOMString(MayBeNull { type_: DOMString, q_mark: None }))) }, Comma, AttributedType { attributes: None, type_: Single(NonAny(Identifier(MayBeNull { type_: Identifier("AudioParam"), q_mark: None }))) }), close_angle: GreaterThan }, semi_colon: SemiColon })
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL Stringifier interface member: Exception Stringifier(StringifierMember { attributes: None, stringifier: Stringifier, semi_colon: SemiColon })
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL Stringifier interface member: DOMMatrixReadOnly Stringifier(StringifierMember { attributes: None, stringifier: Stringifier, semi_colon: SemiColon })
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported webidl stringifier: DOMTokenList OperationInterfaceMember { attributes: None, modifier: Some(Stringifier(Stringifier)), special: None, return_type: Type(Single(NonAny(DOMString(MayBeNull { type_: DOMString, q_mark: None })))), identifier: None, args: Braced { open_brace: OpenBrace, body: Punctuated { list: [], separator: Comma }, close_brace: CloseBrace }, semi_colon: SemiColon }
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL iterable interface member: DOMTokenList Iterable(Single(SingleTypedIterable { attributes: None, iterable: Iterable, generics: Generics { open_angle: LessThan, body: AttributedType { attributes: None, type_: Single(NonAny(DOMString(MayBeNull { type_: DOMString, q_mark: Some(QMark) }))) }, close_angle: GreaterThan }, semi_colon: SemiColon }))
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL iterable interface member: FormData Iterable(Double(DoubleTypedIterable { attributes: None, iterable: Iterable, generics: Generics { open_angle: LessThan, body: (AttributedType { attributes: None, type_: Single(NonAny(USVString(MayBeNull { type_: USVString, q_mark: None }))) }, Comma, AttributedType { attributes: None, type_: Single(NonAny(Identifier(MayBeNull { type_: Identifier("FormDataEntryValue"), q_mark: None }))) }), close_angle: GreaterThan }, semi_colon: SemiColon }))
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL iterable interface member: Headers Iterable(Double(DoubleTypedIterable { attributes: None, iterable: Iterable, generics: Generics { open_angle: LessThan, body: (AttributedType { attributes: None, type_: Single(NonAny(ByteString(MayBeNull { type_: ByteString, q_mark: None }))) }, Comma, AttributedType { attributes: None, type_: Single(NonAny(ByteString(MayBeNull { type_: ByteString, q_mark: None }))) }), close_angle: GreaterThan }, semi_colon: SemiColon }))
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL Stringifier interface member: HTMLHyperlinkElementUtils Stringifier(StringifierMember { attributes: None, stringifier: Stringifier, semi_colon: SemiColon })
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL Stringifier interface member: Location Stringifier(StringifierMember { attributes: Some(Bracketed { open_bracket: OpenBracket, body: Punctuated { list: [NoArgs(ExtendedAttributeNoArgs(Identifier("Throws"))), NoArgs(ExtendedAttributeNoArgs(Identifier("NeedsSubjectPrincipal")))], separator: Comma }, close_bracket: CloseBracket }), stringifier: Stringifier, semi_colon: SemiColon })
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL iterable interface member: MediaKeyStatusMap Iterable(Double(DoubleTypedIterable { attributes: None, iterable: Iterable, generics: Generics { open_angle: LessThan, body: (AttributedType { attributes: None, type_: Single(NonAny(ArrayBuffer(MayBeNull { type_: ArrayBuffer, q_mark: None }))) }, Comma, AttributedType { attributes: None, type_: Single(NonAny(Identifier(MayBeNull { type_: Identifier("MediaKeyStatus"), q_mark: None }))) }), close_angle: GreaterThan }, semi_colon: SemiColon }))
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL Stringifier interface member: MediaList Stringifier(StringifierMember { attributes: None, stringifier: Stringifier, semi_colon: SemiColon })
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL Maplike interface member: MIDIInputMap Maplike(MaplikeInterfaceMember { attributes: None, readonly: Some(ReadOnly), maplike: Maplike, generics: Generics { open_angle: LessThan, body: (AttributedType { attributes: None, type_: Single(NonAny(DOMString(MayBeNull { type_: DOMString, q_mark: None }))) }, Comma, AttributedType { attributes: None, type_: Single(NonAny(Identifier(MayBeNull { type_: Identifier("MIDIInput"), q_mark: None }))) }), close_angle: GreaterThan }, semi_colon: SemiColon })
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL Maplike interface member: MIDIOutputMap Maplike(MaplikeInterfaceMember { attributes: None, readonly: Some(ReadOnly), maplike: Maplike, generics: Generics { open_angle: LessThan, body: (AttributedType { attributes: None, type_: Single(NonAny(DOMString(MayBeNull { type_: DOMString, q_mark: None }))) }, Comma, AttributedType { attributes: None, type_: Single(NonAny(Identifier(MayBeNull { type_: Identifier("MIDIOutput"), q_mark: None }))) }), close_angle: GreaterThan }, semi_colon: SemiColon })
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL iterable interface member: NodeList Iterable(Single(SingleTypedIterable { attributes: None, iterable: Iterable, generics: Generics { open_angle: LessThan, body: AttributedType { attributes: None, type_: Single(NonAny(Identifier(MayBeNull { type_: Identifier("Node"), q_mark: Some(QMark) }))) }, close_angle: GreaterThan }, semi_colon: SemiColon }))
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL Stringifier interface member: Range Stringifier(StringifierMember { attributes: Some(Bracketed { open_bracket: OpenBracket, body: Punctuated { list: [NoArgs(ExtendedAttributeNoArgs(Identifier("Throws")))], separator: Comma }, close_bracket: CloseBracket }), stringifier: Stringifier, semi_colon: SemiColon })
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL Maplike interface member: RTCStatsReport Maplike(MaplikeInterfaceMember { attributes: None, readonly: Some(ReadOnly), maplike: Maplike, generics: Generics { open_angle: LessThan, body: (AttributedType { attributes: None, type_: Single(NonAny(DOMString(MayBeNull { type_: DOMString, q_mark: None }))) }, Comma, AttributedType { attributes: None, type_: Single(NonAny(Object(MayBeNull { type_: Object, q_mark: None }))) }), close_angle: GreaterThan }, semi_colon: SemiColon })
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported webidl stringifier: Selection OperationInterfaceMember { attributes: None, modifier: Some(Stringifier(Stringifier)), special: None, return_type: Type(Single(NonAny(DOMString(MayBeNull { type_: DOMString, q_mark: None })))), identifier: None, args: Braced { open_brace: OpenBrace, body: Punctuated { list: [], separator: Comma }, close_brace: CloseBrace }, semi_colon: SemiColon }
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL Stringifier interface member: URL Stringifier(StringifierMember { attributes: None, stringifier: Stringifier, semi_colon: SemiColon })
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL iterable interface member: URLSearchParams Iterable(Double(DoubleTypedIterable { attributes: None, iterable: Iterable, generics: Generics { open_angle: LessThan, body: (AttributedType { attributes: None, type_: Single(NonAny(USVString(MayBeNull { type_: USVString, q_mark: None }))) }, Comma, AttributedType { attributes: None, type_: Single(NonAny(USVString(MayBeNull { type_: USVString, q_mark: None }))) }), close_angle: GreaterThan }, semi_colon: SemiColon }))
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL Stringifier interface member: URLSearchParams Stringifier(StringifierMember { attributes: None, stringifier: Stringifier, semi_colon: SemiColon })
[web-sys 0.3.14] [2019-02-18T16:44:54Z WARN  wasm_bindgen_webidl::first_pass] Unsupported WebIDL Stringifier interface member: WorkerLocation Stringifier(StringifierMember { attributes: None, stringifier: Stringifier, semi_colon: SemiColon })
[web-sys 0.3.14] cargo:rustc-env=BINDINGS=C:\git\wasm-bindgen\target\release\build\web-sys-6530c5b6f7b8a8d8\out\bindings.rs
[web-sys 0.3.14] cargo:rerun-if-env-changed=WEBIDL_RUSTFMT_BINDINGS

Note that I added the logging of self_name for these logs to more easily see what was being skipped due to an usupported WebIDL.

After running cargo build, I tried both accessing the features through my project (using a [patch.crate-io] in the .toml file) and using cargo doc --open to search for the APIs. Cusiously, doc/web_sys/all.html does not have anything listed and running a search for ANGLE_instanced_arrays yields no results, but neither does WebGlRenderingContext.

I'm not sure what the next step forward is from here.

[ZacLiveEarth]

Some additional info:

The docs for supporting-more-web-apis indicate that the generated rust bindings should be at target/wasm32-unknown-unknown/debug/build/ However, I only get target/debug/build (the wasm32-unknown-unknown) directory is missing. The bindings.rs file under the target that I do have is pretty sparse and doesn't appear to contain any apis.

[ZacLiveEarth]

Additionally, I have tried adding --target wasm32-unknown-unknown to the command line to cargo build, which does generate the directory under the expected path (perhaps the docs here should be updated to add the target) but, the bindings.rs file is still sparse.

[ZacLiveEarth]

Made some progress... (is there a Discord or something where I can chat with someone in the know? I think a lot of these hangups are just learning curve and not relevant to the issue)

I found that the build does not include features unless specified. Trying to compile with all features leads to this bug - https://github.com/rustwasm/wasm-bindgen/issues/1273. So, I compiled specifically with the features needed by my project.

With just these features, ANGLE_instanced_arrays does not show up in bindings.rs (though, many things do now). Unsure the mapping between a feature and the APIs, I tried searching for other examples that already have features. For example, WebGlFramebuffer. There was nothing in the source that seemed to map the feature to the list of APIs, so I concluded it must be dynamic. I tried then to add an ANGLE_instanced_arrays = [] to the Cargo.toml file, and added the same to --features on cargo build. This did not yield any new API in bindings.rs.

Following the WebGlFramebuffer example as a guide, I guessed that perhaps adding the [Exposed] attribute would help, and added [Exposed=(Window,Worker), Func="mozilla::dom::OffscreenCanvas::PrefEnabledOnWorkerThread"] to the ANGLE_instanced_arrays interface. Again, this yielded no result.

Next, I tried outputting __WASM_BINDGEN_DUMP_FEATURES to a file, to see if it would show up there. It did not.

[alexcrichton]

We do indeed have a discord!

Looks like you've made some good progress though. In theory __WASM_BINDGEN_DUMP_FEATURES should work for dumping all the features, although the feature will likely not be called ANGLE_instanced_arrays as we rustify the name so you'll want to do a bit of a fuzzy search over the output file to see if it's in there I think

[LaylBongers]

I'm interested in extensions being supported as well. A few extensions are critical for performance and quality in webgl1, with webgl2 still not being supported by Edge.