Changing psychtoolbox screen

Question

I am using Psychtoolbox to display on a screen as part of an interface. I create a blank screen with [win,Rect]=Screen('OpenWIndow',etc.etc...) in my main script. I would like to use a function call later on in the script to update the screen, but I have no idea how to get the values in and out of the function to change the Screen.

So something like:

%main script
[win,Rect]=Screen('OpenWIndow',0,[0 0 0],[0 0 1280 1024]);

%do other processing (in my case communicating with another computer.)

DrawStuff() %function that takes variables from script and updates the screen

% continue script

Answer 1

Screen('Flip',win) is what you are looking for, but you need to issue some drawing commands for it to show anything.

Please read the file PsychDocumentation/PTBTutorial-ECVP2013.pdf in the psychtoolbox distribution to understand the basics of stimulus presentation.