程式語言 - X Window (X11) - C/C++ - Draw Line

參考資訊：
https://github.com/QMonkey/Xlib-demo
https://people.scs.carleton.ca/~claurend/Courses/COMP2401/Notes/COMP2401_Ch8_Graphics.pdf

main.c

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <X11/Xlib.h>
  
int main(int argc, char *argv[])
{
    GC gc = 0;
    Window win = 0;
    Display *display = NULL;
    XPoint pt[3] = { {50, 50}, {10, 70}, {90, 90} };
    XSegment sg[1] = { { 10, 200, 300, 200} };
 
    display = XOpenDisplay(NULL);
    win = XCreateSimpleWindow(
        display,
        RootWindow(display, 0),
        0,
        0,
        320,
        240,
        0,
        0,
        0xffffff);
  
    XStoreName(display, win, "main");
    gc = XCreateGC(display, win, 0, NULL);
    XMapWindow(display, win);
    XFlush(display);
    usleep(100000);
  
    XSetForeground(display, gc, 0);
    XDrawLine(display, win, gc, 10, 10, 100, 10);
    XDrawLines(display, win, gc, pt, 3, CoordModeOrigin);
    XDrawSegments(display, win, gc, sg, 1);
    XFlush(display);
    usleep(3000000);
  
    XUnmapWindow(display, win);
    XDestroyWindow(display, win);
    XCloseDisplay(display);
  
    return 0;
}

編譯、測試

$ gcc main.c -o main -lX11
$ ./main