使用xlib绘制具有透明颜色的图形

#include <X11/Xlib.h>

int main() {
  Display *display;
  Window window;
  XEvent event;
  
  // 连接到X服务器
  display = XOpenDisplay(NULL);
  
  // 创建窗口
  window = XCreateSimpleWindow(display, DefaultRootWindow(display), 0, 0, 800, 600, 0, 0, 0);
  
  // 设置透明属性
  XSetWindowAttributes attrib;
  attrib.background_pixel = 0;
  attrib.border_pixel = 0;
  attrib.colormap = XCreateColormap(display, window, DefaultVisual(display, 0), AllocNone);
  attrib.event_mask = ExposureMask;
  XChangeWindowAttributes(display, window, CWBackPixel | CWBorderPixel | CWColormap | CWEventMask, &attrib);
  
  // 创建图形上下文
  GC gc = XCreateGC(display, window, 0, NULL);
  
  // 设置绘制属性
  XSetForeground(display, gc, 0xFF0000);
  
  // 绘制图形
  XDrawRectangle(display, window, gc, 100, 100, 200, 200);
  
  // 显示窗口
  XMapWindow(display, window);
  
  while (1) {
    XNextEvent(display, &event);
    
    if (event.type == Expose) {
      // 处理Expose事件
    }
  }
  
  XCloseDisplay(display);
  
  return 0;
}