我之前也遇到过类似的问题,但现在发生的情况是我尝试使用 GNU libplot 绘制五个圆圈,等待几秒钟,然后让窗口变黑。发生的情况是屏幕开始变黑,等待指定的时间,然后进行绘制。如何使用 sleep 来获得所需的输出?我将省略为时间结构赋值的代码
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <plot.h>
#include <unistd.h>
struct body {
char color[10];
char size[4];
char mass[10];
char xpos[10];
char ypos[10];
};
int main() {
struct body sun;
struct body mercury;
struct body venus;
struct body earth;
struct body mars;
plPlotter *plotter;
plPlotterParams *plotterParams;
plotterParams = pl_newplparams();
pl_setplparam(plotterParams, "BITMAPSIZE", "750x750");
pl_setplparam(plotterParams, "USE_DOUBLE_BUFFERING", "no");
pl_setplparam(plotterParams, "BG_COLOR", "black");
if ((plotter = pl_newpl_r("X", stdin, stdout, stderr, plotterParams)) == NULL) {
fprint(stderr, "Couldn't create Plotter\n");
exit(1);
} else if(pl_openpl_r(plotter) < 0) {
fprintf(stderr, "Couldn't open Xwindows Plotter\n");
exit(1);
}
pl_fspace_r(plotter, -2500, -2500, 2500, 2500);
pl_pentype_r(plotter, 1);
pl_filltype_r(plotter, 1);
pl_pencolorname_r(plotter, "black");
/* draw the sun */
pl_fillcolorname_r(plotter, sun.color);
pl_fcircle_r(plotter, atof(sun.size), atof(sun.ypos), atof(sun.size));
/* I do this same thing 4 more times but with
* mercury, venus, earth, and mars
*/
sleep(5); /* try to wait 5 seconds then sleep */
/* close and cleanup */
if (pl_close_pl_r(plotter) < 0) {
fprintf(stderr, "Couldnt delete plotter\n");
}
else if (pl_deletepl_r(plotter) < 0) {
fprintf(stderr, "Couldnt delete plotter\n");
}
return 0;
}
最佳答案
你在哪里:
plotterParams = pl_newplparams();
pl_setplparam(plotterParams, "BITMAPSIZE", "750x750");
pl_setplparam(plotterParams, "USE_DOUBLE_BUFFERING", "no");
pl_setplparam(plotterParams, "BG_COLOR", "black");
您将“BG_COLOR”设置为黑色。
我对这套特定的工具不太了解,但看起来您从一开始就将背景设置为黑色。
在您的情况下,您想要做的是将其最初设置为白色(或其他),然后在完成后将其更改为黑色。希望这能让您走上正轨。
关于c - sleep() 函数未按预期工作,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/22239998/