In a later PR, DomRoot<T> will become a type alias of Root<Dom<T>>,
where Root<T> will be able to handle all the things that need to be
rooted that have a stable traceable address that doesn't move for the
whole lifetime of the root. Stay tuned.
This improves the encapsulation and consistency in our WebGL
implementation.
Also allows to implement new methods such as `getShaderSource()`.
It will also allow us to use `delete()` in the destructors of them (note
that we will want to keep track of them from the context).
This commit implements:
* WebGLFramebuffer
* WebGLRenderbuffer
* WebGLTexture
And adds the following methods to `WebGLRenderingContext`:
* create{Texture,Framebuffer,Renderbuffer}
* bind{Texture,Framebuffer,Renderbuffer}
* destroy{Buffer,Texture,Framebuffer,Renderbuffer}
Fixes:
* WebGLUniform location shouldn't inherit from WebGLObject.
Known Issues:
* WebGL objects have to be destroyed on drop, we may want to keep a reference to the context, or maybe a clone of the renderer to achieve this
Also refactors a huge part of the current implementation, to allow
failing on creation of different WebGL objects.
Blocked on https://github.com/servo/gleam/pull/22
A reftest for most of the added functionality is not doable right now,
we need a few more functions in order to upload a texture, for example.
