FrameBufferView

[danem]

Consider reintroducing FrameBufferView as an API for reading from the FrameBuffer. The base FrameBuffer API has no way of reading because this isn't necessarily possible across all backends. By introducing a FrameBufferView interface we could add another degree of freedom, and let users define this for their platform. The key questions are:

• What value does this add?
  • When would they need to read pixels? For scrolling?
• What would an interface that works across memory and hardware look like?
  • The interface would likely have to be read-only.