Can you create a Texture Array?

1
I seem to be having trouble creating a true array of textures...

I am setting up the array like this:

instIMG(1)=Screen('MakeTexture', MainWindow, double(imread('Slide1.png')));
instIMG(2)=Screen('MakeTexture', MainWindow, double(imread('Slide2.png')));
instIMG(3)=Screen('MakeTexture', MainWindow, double(imread('Slide3.png')));
instStim = zeros(1,3);
for o = 1:3
instStim(o) = Screen('OpenOffscreenWindow', MainWindow, [], [0 0 1134 708]);
Screen('DrawTexture', instStim(o), instIMG(o));
end

...and then trying to use like this later:

Screen('DrawTexture', stimWindow, instStim(InstCnt), [], []); % Instruction 1

...where InstCnt is a counter which increments with user clicks of the mouse.

If I do it like that it coughs up a screen error regrading use of Screen. But if I do it like this:

switch InstCnt
case 1
Screen('DrawTexture', stimWindow, instStim(1), [], []); % Instruction 1
case 2
Screen('DrawTexture', stimWindow, instStim(2), [], []); % Instruction 2
case 3
Screen('DrawTexture', stimWindow, instStim(3), [], []); % Instruction 3
end

...it works fine. But that pretty much defeats the point of creating the array in the first place.

Thanks for your help

Tom