The most viable approach these days is for 2D is to use the 3D hardware. There's no standard, usable API for 2D accelerated drawing the way there is for 3D, nor does it quite make sense for there to be one.
(No, OpenVG is not viable. No, Xrender is not viable. cairo and Skia both use the 3D hardware in combination with a CPU render engine.)
(No, OpenVG is not viable. No, Xrender is not viable. cairo and Skia both use the 3D hardware in combination with a CPU render engine.)