Question

这个简短的程序应该显示绿色的全屏背景和中心有一个400 x 400像素的红色正方形。但是，红色方块位于顶部左侧角[0, 0, 400, 400]而不是居中。

try
    screens = Screen('Screens'); % check for number of screens (currently '0' because only one screen is connected)
    whichscreen = max(screens);
    [myscreen,rect]=Screen('OpenWindow', whichscreen, [0, 255,0]);
    screen_rect = [0, 0, 1366, 768];
    square_size = [0, 0, 400, 400];
    square_rect = CenterRect(square_size, screen_rect);
    Screen('FillRect', myscreen, [255, 0, 0], square_size);
    Screen('Flip', myscreen);
    KbWait;
    Screen('CloseAll');
catch
    Screen('CloseAll');
end

此外，按下键盘上的按钮时程序不会关闭。

知道问题是什么吗？

谢谢＆amp;最好， Ĵ

Answer 1

您使用的是错误的变量。您正在绘制一个矩形到square_size而不是square_rect - 因此很明显矩形被绘制到[0, 0, 400, 400]。

try
    screens = Screen('Screens'); % check for number of screens (currently '0' because only one screen is connected)
    whichscreen = max(screens); % 
    [myscreen,rect]=Screen('OpenWindow', whichscreen, [0, 255,0]);
    screen_rect = [0, 0, 1366, 768];
    square_size = [0, 0, 400, 400];
    square_rect = CenterRect(square_size, screen_rect);
    Screen('FillRect', myscreen, [255, 0, 0], square_rect);
    Screen('Flip', myscreen);
    KbWait;
    Screen('CloseAll');
catch
    Screen('CloseAll');
end

此外，您可以使用rect提供的Screen('OpenWindow')变量，将其缩短并兼容您使用的每台显示器。

try
    screens = Screen('Screens');
    whichscreen = max(screens);
    [myscreen,rect]=Screen('OpenWindow', whichscreen, [0, 255,0]);
    square_size = [0, 0, 400, 400];
    square_position = CenterRect(square_size, rect);
    Screen('FillRect', myscreen, [255, 0, 0], square_position);
    Screen('Flip', myscreen);
    KbWait;
    Screen('CloseAll');
catch
    Screen('CloseAll');
end

Matlab 2015＆amp; Psychtoolbox 3：CenterRect - 方形不居中

1 个答案: