The PdePreprocessor in the Java mode is not parsing the renderer when the sketch is in fullscreen mode: https://github.com/processing/processing4/blob/master/java/src/processing/mode/java/preproc/PdeParseTreeListener.java#L718 Current workaround is to use ```size(displayWidth, displayHeight, RENDERER)``` instead of ```fullScreen(RENDERER)```