[jayd16]

>As we do not have control over the binding of the texture and the Unity context, the current design for updating this texture uses a blit (copy) via Servo’s surfman-chains API

I don't think this is necessary. You should be able to make Texture objects that ref existing native textures in Unity and I've been able to use OES_EGL_image_external extensions to sample Android decoded video textures sampled from Unity shaders.

Its not the most widely available option but the perf is much better.

[phil_moz]

The issue is not access to an external texture, it's access to an external texture on the right thread in the right GL context. We did look at writing a new backend for surfman to integrate directly, but it's a bit of work and not at all cross-platform, so this was not a goal of the project at this stage. I'd like to find a way to avoid the blit though, so I'm continuing to experiment in this direction.