refactor to prepare for radial motion

Author: Remi-Gau

apertureTexture.m

@@ -40,6 +40,10 @@
                     Screen('FillOval', cfg.aperture.texture, transparent, ...
                         CenterRectOnPoint([0 0 repmat(diameter, 1, 2)], ...
                         xPos, yPos));
+                    
+                otherwise
+                    
+                    error('unknown aperture type: %s.', cfg.aperture.type);
 
             end
 

src/dot/computeCartCoord.m

@@ -0,0 +1,5 @@
+function cartesianCoordinates = computeCartCoord(positions, cfg)
+    cartesianCoordinates = ...
+        [positions(:,1) - cfg.screen.winWidth /  2, ... % x coordinate
+        positions(:,2) + cfg.screen.winWidth / 2]; % y coordinate
+end

src/dot/computeRadialMotionDirection.m

@@ -1,16 +1,13 @@
-function direction = computeRadialMotionDirection(cfg, positions, direction)
-    if strcmp(cfg.design.motionType, 'radial')
-
-        cartesianCoordinates = positions - cfg.screen.winWidth /  2;
-
-        [angle, ~] = cart2pol(cartesianCoordinates(:, 1), cartesianCoordinates(:, 2));
-        angle = angle / pi * 180;
-
-        if direction == -666
-            angle = angle - 180;
-        end
-
-        direction = angle;
-
+function angleMotion = computeRadialMotionDirection(cfg, dots)
+    
+    cartesianCoordinates = computeCartCoord(dots.positions, cfg);
+    
+    [angleMotion, ~] = cart2pol(cartesianCoordinates(:, 1), cartesianCoordinates(:, 2));
+    angleMotion = angleMotion / pi * 180;
+    
+    if dots.direction == -666
+        angleMotion = angleMotion - 180;
     end
+    
 end
+

src/dot/initDots.m

@@ -18,32 +18,32 @@
     % TODO
     % bound direction between 0 and 360 ??
 
-    direction = thisEvent.direction(1);
+    dots.direction = thisEvent.direction(1);
 
     speedPixPerFrame = thisEvent.speed(1);
 
     lifeTime = cfg.dot.lifeTime;
 
     % decide which dots are signal dots (1) and those are noise dots (0)
-    isSignal = rand(cfg.dot.number, 1) < cfg.dot.coherence;
+    dots.isSignal = rand(cfg.dot.number, 1) < cfg.dot.coherence;
 
     % for static dots
-    if direction == -1
+    if dots.direction == -1
         speedPixPerFrame = 0;
         lifeTime = Inf;
-        isSignal = true(cfg.dot.number, 1);
+        dots.isSignal = true(cfg.dot.number, 1);
     end
 
     %% 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
-    positions = rand(cfg.dot.number, 2) * cfg.screen.winWidth;
+    dots.positions = rand(cfg.dot.number, 2) * cfg.screen.winWidth;
 
     %% Set vertical and horizontal speed for all dots
-    directionAllDots = setDotDirection(cfg, positions, direction, isSignal);
+    dots = setDotDirection(cfg, dots);
 
-    [horVector, vertVector] = decomposeMotion(directionAllDots);
+    [horVector, vertVector] = decomposeMotion(dots.directionAllDots);
     speeds = [horVector, vertVector];
 
     % we were working with unit vectors. we now switch to pixels
@@ -61,20 +61,8 @@
     dots.lifeTime = lifeTime;
     dots.time = time;
     dots.speeds = speeds;
-    dots.isSignal = isSignal;
-    dots.positions = positions;
-end
-
-function directionAllDots = setDotDirection(cfg, positions, direction, isSignal)
-
-    directionAllDots = nan(cfg.dot.number, 1);
+    dots.speedPixPerFrame = speedPixPerFrame;
 
-    direction = computeRadialMotionDirection(cfg, positions, direction);
+end
 
-    % Coherent dots
-    directionAllDots(isSignal) = direction;
-    % Random direction for the non coherent dots
-    directionAllDots(~isSignal) = rand(sum(~isSignal), 1) * 360;
-    directionAllDots = rem(directionAllDots, 360);
 
-end

src/dot/reseedDots.m

@@ -1,21 +1,39 @@
 function dots = reseedDots(dots, cfg)
-
+    
+    fixationWidthPix = 0;
+    if isfield(cfg.fixation, 'widthPix')
+        fixationWidthPix = cfg.fixation.widthPix;
+    end
+    
+    cartesianCoordinates = computeCartCoord(dots.positions, cfg);
+    [~, radius] = cart2pol(cartesianCoordinates(:, 1), cartesianCoordinates(:, 2));
+    
     % 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
+    % - is on the fixation cross
     % - 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) ;
+        radius - cfg.dot.sizePix < fixationWidthPix / 2, ...
+        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 = setDotDirection(cfg, dots);
+        [horVector, vertVector] = decomposeMotion(dots.directionAllDots);
+        dots.speeds = [horVector, vertVector] * dots.speedPixPerFrame;
+        
         dots.time(N, 1) = 1;
     end
-
-end
+    
+end

src/dot/setDotDirection.m

@@ -0,0 +1,19 @@
+function dots = setDotDirection(cfg, dots)
+
+    directionAllDots = nan(cfg.dot.number, 1);
+
+    % Coherent dots
+    directionAllDots(dots.isSignal) = dots.direction;
+    
+    if strcmp(cfg.design.motionType, 'radial')
+        angleMotion = computeRadialMotionDirection(cfg, dots);
+        directionAllDots(dots.isSignal) = angleMotion;
+    end
+
+    % Random direction for the non coherent dots
+    directionAllDots(~dots.isSignal) = rand(sum(~dots.isSignal), 1) * 360;
+    directionAllDots = rem(directionAllDots, 360);
+    
+    dots.directionAllDots = directionAllDots;
+
+end

src/dot/updateDots.m

@@ -9,10 +9,10 @@
 
         error(errorStruct);
     end
-
-    dots = reseedDots(dots, cfg);
-
+    
     % Add one frame to the dot lifetime to each dot
     dots.time = dots.time + 1;
 
+    dots = reseedDots(dots, cfg);
+
 end

tests/test_reseedDots.m

@@ -0,0 +1,45 @@
+function test_suite = test_reseedDots %#ok<*STOUT>
+    try % assignment of 'localfunctions' is necessary in Matlab >= 2016
+        test_functions = localfunctions(); %#ok<*NASGU>
+    catch % no problem; early Matlab versions can use initTestSuite fine
+    end
+    initTestSuite;
+end
+
+function test_reseedDotsBasic()
+    
+    dots.lifeTime = 100;
+    cfg.screen.winWidth = 2000;
+    cfg.dot.number = 5;
+    cfg.dot.sizePix = 20;
+    cfg.dot.proportionKilledPerFrame = 0;
+    
+    cfg.fixation.widthPix = 20;
+    
+    dots.positions = [ ...
+        694, 100; % OK
+        490, 2043; % out of frame
+        -104, 392; % out of frame 
+        492, 402; % OK
+        1000, 1000; % on the fixation cross
+        ];
+    
+    dots.time = [...
+        6; ... OK
+        4 ; ... OK
+        56; ... OK
+        300; ... % exceeded its life time
+        50]; % OK
+    
+    dots = reseedDots(dots, cfg);
+    
+    reseeded = [...
+        6;
+        1;
+        1;
+        1;
+        1];
+    
+    assertEqual(reseeded, dots.time)
+   
+end