Hello guys !
For me, drawing an image in a thread (and rendering it then with the repaint call) is probably going to help the visualisation component to work whatever happens around it (other plug-ins using a lot of CPU for example) without any important slowdown.
However, I don’t see why doing that could save some extra CPU in the ideal situation, when the component is the only thing alive in the DAW context. If the refresh rate is 60 FPS, you still need to draw the content of the image and to draw the image on the Graphics context 60 times per second.
And obviously if the operations that had to be done on the Graphics context are less hungry than drawing an image, it could be better to do everything directly in the paint function.