refactor update dots

Author: Remi-Gau

reseedDots.m

@@ -0,0 +1,21 @@
+function dots = reseedDots(dots, cfg)
+    
+    % Create a logical vector to detect any dot that has:
+    % - an xy position inferior to 0
+    % - an xy position superior to winWidth
+    % - has exceeded its liftime
+    % - has been been picked to be killed
+    N = any([ ...
+        dots.positions > cfg.screen.winWidth, ...
+        dots.positions < 0, ...
+        dots.time > dots.lifeTime, ...
+        rand(cfg.dot.number, 1) < cfg.dot.proportionKilledPerFrame], 2) ;
+
+    % If there is any such dot we relocate it to a new random position
+    % and change its lifetime to 1
+    if any(N)
+        dots.positions(N, :) = rand(sum(N), 2) * cfg.screen.winWidth;
+        dots.time(N, 1) = 1;
+    end
+    
+end

updateDots.m

@@ -6,29 +6,13 @@
     if all(isnan(dots.positions(:)))
         errorStruct.message = 'All dots position have NaN values.';
         errorStruct.identifier = 'updateDots:onlyNans';
-        
+
         error(errorStruct);
     end
 
-    % Create a logical vector to detect any dot that has:
-    % - an xy position inferior to 0
-    % - an xy position superior to winWidth
-    % - has exceeded its liftime
-    % - has been been picked to be killed
-    N = any([ ...
-        dots.positions > cfg.screen.winWidth, ...
-        dots.positions < 0, ...
-        dots.time > dots.lifeTime, ...
-        rand(cfg.dot.number, 1) < cfg.dot.proportionKilledPerFrame], 2) ;
-
-    % If there is any such dot we relocate it to a new random position
-    % and change its lifetime to 1
-    if any(N)
-        dots.positions(N, :) = rand(sum(N), 2) * cfg.screen.winWidth;
-        dots.time(N, 1) = 1;
-    end
+    dots = reseedDots(dots, cfg);
 
     % Add one frame to the dot lifetime to each dot
     dots.time = dots.time + 1;
-    
+
 end