For a real-time interactive Mandelbrot viewer I was making in R & Rcpp+OpenMP & Shiny I am on the lookout for a performant way to display 1920x1080 matrices as raste
According to the RGL package introduction, it is :
a visualization device system for R, using OpenGL as the rendering backend. An rgl device at its core is a real-time 3D engine written in C++. It provides an interactive viewpoint navigation facility (mouse + wheel support) and an R programming interface.
As RGL is a real time 3D engine, I expect that using RGL for 2D will give you a fast display.
Please note that this is an old project so I am not sure that it fit your requirement.
You can take a look on this paper and see some result images in this gallery