The primary purpose of these is to add bounds checking to older OpenGL
API calls that take arbitrarily sized buffers, but don't know the size
of the buffer and thus rely on the application being certain the buffer
is large enough.
Since these API calls are exposed to arbitrary JS which can make
arbitrarily sized buffers, it is not safe to use the non-robust
variants, as we cannot know the size of the buffer ahead of time, nor
the amount of data required by the API call.
The robust variants provided by ANGLE adds a buffer size parameter,
where it'll calculate the amount of data it needs for that API call
for us and return an error if it's bigger than the given buffer size.
Credit to https://github.com/s41nt0l3xus for finding this during a CTF
and providing a write up that exploits this.
See: 92efbaed6c/gpnctf-2025/WebGL-bird
Add OffscreenCanvas to TexImageSource and CanvasImageSource.
Implement all the necessary features to make it work in all cases where
these types are used.
There's a bit of a UTF-8 assumption with this change. But nearly every
caller of these methods were immediately creating a String from the
resulting ByteString anyways.
This is done by using the combination of format and type to map to the
appropriate Skia bitmap type. With this, we then read the SkImage of
the TexImageSource into a new SkPixmap with the destination format
information and holding an appropriately sized buffer. Once created,
readPixels is called to convert and write the image into the buffer.
This is required to return original references to the shaders attached
to a program from getAttachedShaders. This is required for Figma (and
likely all other Emscripten compiled applications that use WebGL) to
get it's own generated shader IDs from the shaders returned from
getAttachedShaders.
Returning numbers instead of booleans for the statuses made Ruffle
(through the wgpu crate) think a shader/program failed to compile/link,
as it does a strict type comparison.
Required by https://qwasm2.m-h.org.uk, which adds a custom `name`
attribute to objects it generates. It then gets some of these objects
out with getParameter, and expects the `name` attribute to be there.
This way we could be sure that context object won't be deallocated
before any of the objects that belong to it.
Having a context pointer is also going to be used in upcoming changes
to generate an INVALID_OPERATION error if an object does not belong to
the context it's being used in.
