Psychtoolbox/ Draw four rectangles.
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PsychDefaultSetup(2);
+Screen('Preference', 'SkipSyncTests', 1);
+
+screens = Screen('Screens');
+screenNumber = max(screens);
+
+white = WhiteIndex(screenNumber);
+black = BlackIndex(screenNumber);
+
+[wPtr, rect] = PsychImaging('OpenWindow', screenNumber, black);
+
+[screenXpixels, screenYpixels] = Screen('WindowSize', wPtr);
+[xCenter, yCenter] = RectCenter(rect);
+
+baseRect = [0 0 100 100];
+
+squareXpos = [screenXpixels * 0.15 screenXpixels * 0.25 screenXpixels * 0.35 screenXpixels * 0.45];
+squareYpos = [screenYpixels * 0.15 screenYpixels * 0.25 screenYpixels * 0.35 screenYpixels * 0.45];
+numSquares = length(squareXpos);
+
+allColors = [1 0 0; 0 1 0; 0 0 1; 1 0 0];
+
+
+allRects = nan(4, 4);
+for i = 1:numSquares
+ allRects(:, i) = CenterRectOnPointd(baseRect, squareXpos(i), squareYpos(i));
+
+end
+
+Screen('FillRect', wPtr, allColors, allRects);
+Screen('Flip', wPtr);
+
+KbWait;
+sca;
I'd like to draw four rectangles. But there is a error like "Screen('FillRect', windowPtr [,color] [,rect] )" . I don't know why this code has a error... Please, help me...!
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Answers (1)
Mikel Jimenez
on 20 Jun 2022
Hi,
I think you need to provide allColors and allRects as column vectors:
"Instead of filling one rectangle, you can also specify a list of multiple rectangles to be filled - this is much faster when you need to draw many rectangles per frame. To fill n rectangles, provide “rect” as a 4 rows by n columns matrix, each column specifying one rectangle, e.g., rect(1,5)=left border of 5th rectange, rect(2,5)=top border of 5th rectangle, rect(3,5)=right border of 5th rectangle, rect(4,5)=bottom border of 5th rectangle. If the rectangles should have different colors, then provide “color” as a 3 or 4 row by n column matrix, the i’th column specifiying the color of the i’th rectangle."
Not sure if you are doing it this way, yet I guess you have sorted this out by now.
Best,
Mikel
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