This patch adds support for Viewer and File Output nodes to the realtime
compositor. The experimental render GPU compositor was also extended to
support viewers. While support for File Output nodes was added, it
remains unimplemented.
This is just an experimental implementation, the logic for viewers will
probably be changed once #108656 is agreed upon. Furthermore, the recalc
NODE_DO_OUTPUT_RECALC flags need to be taken into account to avoid
superfluous computations.
Omar Emara