This function retrives a pixel from window to force the windowing
system to carry out any pending rendering commands.
This function is intended to be used to syncronize with rendering
pipelines, to benchmark windowing system rendering operations.
Since 2.14
This function retrives a pixel from window to force the windowing system to carry out any pending rendering commands. This function is intended to be used to syncronize with rendering pipelines, to benchmark windowing system rendering operations. Since 2.14