Compositor / Renderer

[Daniel van Vugt]

All,

I've been trying to keep my hands out of the compositor/renderer stuff 
recently while alan_g and kdub move large parts around, but I keep 
thinking of a nicer design and wonder if anyone's thought about it...

Presently we have:
DefaultDisplayBufferCompositor implements bypass decision logic and then 
calls (delegates to) GLRenderer.
That's two classes with problems:
   (a) Naming things "Default"-anything doesn't tell you how the class 
is different to its parent and surroundings.
   (b) Naming things "Renderer" is based on a verb so does not fit well 
with peoples mental models, leading to misunderstandings and disagreement.

I suggest a nicer design would be:
BypassCompositor class implements bypass decision logic (only).
GLCompositor inherits from BypassCompositor and implements GL-specific 
rendering (replacing GLRenderer and DefaultDisplayBufferCompositor).

Admittedly "Compositor" has the verb naming problem too, but it reduces 
the number of classes which have that problem.

I would normally propose such a change in code, but again, am trying to 
avoid stepping on other peoples' toes in that area.

- Daniel