> These are supported in XRender. But even if they were not, it's always possible to extend it. For example older XRender version (more than 10 years ago) have not supported gradinets, gradients were added later.
Hah. It's funny that in one paragraph you talk about how optional extensions are great and then in the next paragraph you blame OpenGL for optional extensions.
> But that's not important because Wayland has nothing like XRender, so in that part its worse than Xorg anyway.
Nope. Wayland simply doesn't need it.
> You mix hardware and drivers support.
No I don't. An uber-great architecture is useless if there's no hardware for it.
> Do you know why SNA works faster than EXA on the same hardware?
SNA does not work anywhere except for i965 hardware. So it's kinda irrelevant. Besides, it's only used to implement XRender.
>Do you think that OpenGL/ES is just either supported or not?
Now? Pretty much yes.
>Some feature that you have used to on your video adapter can be missing on another one.
That used to be true 5 years ago. Now OpenGL standards mandate the required extension sets, so one can just check for the implemented OpenGL/EGL level and use functionality from that set.
BTW, how can I check that a certain feature of XRender is accelerated? For example, vmware svga driver supports accelerated compositing but not trapezeoid rendering.