add input checks on drawFieldOfView

Author: Remi-Gau

src/drawFieldOfVIew.m

@@ -6,20 +6,23 @@ function drawFieldOfVIew(cfg)
     % stimuli if you know the FOV of the participant will be obstructed by
     % something
 
-    RED = [255 0 0];
-    penWidth = 2;
-    
-    fov = cfg.screen.effectiveFieldOfView;
-    
-    fov = CenterRect(...
-        [0, 0, fov(1), fov(2)], ...
-        cfg.screen.winRect);
+    if isfield(cfg.screen, 'effectiveFieldOfView') && ...
+        numel(cfg.screen.effectiveFieldOfView)==2
 
-    Screen('FrameRect', ...
-        cfg.screen.win, ...
-        RED, ...
-        fov, ...
-        penWidth);
-    
+        RED = [255 0 0];
+        penWidth = 2;
+
+        fov = cfg.screen.effectiveFieldOfView;
+
+        fov = CenterRect(...
+            [0, 0, fov(1), fov(2)], ...
+            cfg.screen.winRect);
+
+        Screen('FrameRect', ...
+            cfg.screen.win, ...
+            RED, ...
+            fov, ...
+            penWidth);
+    end
 
 end