add functions for RDK from the visual localizer

Author: Remi-Gau

initializeDots.m

@@ -0,0 +1,50 @@
+function [dots] = initializeDots(cfg, thisEvent)
+    
+    direction = thisEvent.direction(1);
+    
+    dots.lifeTime = cfg.dot.lifeTime;
+    
+    speedPixPerFrame = thisEvent.speed(1); 
+    
+    % decide which dots are signal dots (1) and those are noise dots (0)
+    dots.isSignal = rand(cfg.dot.number, 1) < cfg.dot.coherence;
+    
+    % for static dots
+    if direction == -1
+        speedPixPerFrame = 0;
+        dots.lifeTime = cfg.eventDuration;
+        dots.isSignal = ones(cfg.dot.number, 1);
+    end
+    
+    % Convert from seconds to frames
+    dots.lifeTime = ceil(dots.lifeTime / cfg.screen.ifi);
+
+    % Set an array of dot positions [xposition, yposition]
+    % These can never be bigger than 1 or lower than 0
+    % [0,0] is the top / left of the square
+    % [1,1] is the bottom / right of the square
+    dots.positions = rand(cfg.dot.number, 2) * cfg.screen.winWidth;
+    
+    % Set a N x 2 matrix that speed in X and Y 
+    dots.speeds = nan(cfg.dot.number, 2);
+    
+    % Coherent dots
+    [horVector, vertVector] = decompMotion(direction);
+    dots.speeds(dots.isSignal,:) = ...
+        repmat([horVector, vertVector], sum(dots.isSignal), 1);
+    
+    % If not 100% coherence, we get new random direction for the other dots
+    direction = rand(sum(~dots.isSignal), 1) * 360;
+    [horVector, vertVector] = decompMotion(direction);
+    dots.speeds(~dots.isSignal, :) = [horVector, vertVector];
+    
+    % So far we were working wiht unit vectors convert that speed in pixels per
+    % frame
+    dots.speeds = dots.speeds * speedPixPerFrame;
+    
+    % Create a vector to update to dotlife time of each dot
+    % Not all set to one so the dots will die at different times
+    dots.time = floor(rand(cfg.dot.number, 1) * cfg.eventDuration / cfg.screen.ifi);
+    
+end
+

updateDots.m

@@ -0,0 +1,26 @@
+function [dots] = updateDots(dots, cfg)
+    
+    % Move the selected dots
+    dots.positions = dots.positions + dots.speeds;
+
+    % Create a logical vector to detect any dot that has:
+    % - an xy position inferior to 0
+    % - an x position superior to winWidth
+    % - an x position superior to winHeight
+    % - has exceeded its liftime
+    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
+    
+    % Add one frame to the dot lifetime to each dot
+    dots.time = dots.time + 1;
+end