X11 - Xrandr 给我假显示器 [英] X11 - Xrandr giving me false monitors

问题描述

我试图找到所有显示器及其坐标(宽度 w、高度 h、x 原点/左上角 x, 和 y origin/top-left-most y) 并且正在使用此代码，它在某些系统上运行良好.但在其他系统上，我得到错误和重复的条目.如果我测试监视器是否为镜像，我是否能够避免这些重复/错误监视器条目?如何测试它是否是镜像?

I was trying to find all monitors and their coordinates (width w, height h, x origin/top-left-most x, and y origin/top-left-most y) and was using this code, it works good on some systems. But on other systems I get false and duplicate entries. Would I be able to avoid these dupilcate/false monitor entries if I tested if monitor is mirror? How to test if its mirror?

这是我的代码:

// start - get all monitor resolutions
var screen = XRRGetScreenResources(getXOpenDisplay(), getDefaultRootWindow(getXOpenDisplay()));

var noutputs = screen.noutput;

for (var i=noutputs-1; i>=0; i--) {
    var info = XRRGetOutputInfo(getXOpenDisplay(), screen, screen.outputs[i]);
    if (info.connection == RR_Connected) {
        var ncrtcs = info.ncrtc;
        for (var j=ncrtcs-1; j>=0; j--) {
            var crtc_info = XRRGetCrtcInfo(getXOpenDisplay(), screen, infoCrtcs[j]);
            console.info('screen #' + i + ' mon#' + j + ' details:', crtc_info.x, crtc_info.y, crtc_info.width, crtc_info.height);

            collMonInfos.push({
                x: crtc_info.x,
                y: crtc_info.y,
                w: crtc_info.width,
                h: crtc_info.height
            });

            XRRFreeCrtcInfo(crtc_info);
        }
    }
    XRRFreeOutputInfo(info);
}
XRRFreeScreenResources(screen);
console.info('JSON:', JSON.stringify(collMonInfos));
// end - get all monitor resolutions

这会将其输出到日志中:

And this outputs this to log:

"screen #4 mon#0 details:" 0 0 0 0
"screen #3 mon#1 details:" 0 0 1920 1200
"screen #3 mon#0 details:" 1920 469 1366 768
"screen #2 mon#1 details:" 0 0 1920 1200
"screen #2 mon#0 details:" 1920 469 1366 768
"screen #1 mon#1 details:" 0 0 1920 1200
"screen #1 mon#0 details:" 1920 469 1366 768
"screen #0 mon#1 details:" 0 0 1920 1200
"screen #0 mon#0 details:" 1920 469 1366 768

这是 JSON 格式:

This is it in JSON format:

[{
    "x": 0,
    "y": 0,
    "w": 0,
    "h": 0
}, {
    "x": 0,
    "y": 0,
    "w": 1920,
    "h": 1200
}, {
    "x": 1920,
    "y": 469,
    "w": 1366,
    "h": 768
}, {
    "x": 0,
    "y": 0,
    "w": 1920,
    "h": 1200
}, {
    "x": 1920,
    "y": 469,
    "w": 1366,
    "h": 768
}, {
    "x": 0,
    "y": 0,
    "w": 1920,
    "h": 1200
}, {
    "x": 1920,
    "y": 469,
    "w": 1366,
    "h": 768
}, {
    "x": 0,
    "y": 0,
    "w": 1920,
    "h": 1200
}, {
    "x": 1920,
    "y": 469,
    "w": 1366,
    "h": 768
}]

我真的只有两台显示器，一台 1920x1200，一台 1366x768.为什么所有其他条目以及如何进行测试以避免(而不是根据重复项或 0 h/w 回溯过滤掉)?

I really only have 2 monitors, the 1920x1200 one and the 1366x768 one. How come all the other entries and how to test to avoid (rather then filter out in retrospect based on duplicates or 0 h/w)?

推荐答案

您不必要地遍历每个输出，然后遍历每个监视器.所以你会收到一个重复的条目.您不必为每个输出调用 XRRGetOutputInfo，因为您需要的所有数据(监视器数量)都可以在 XRRGetScreenResources 返回的结构中找到.这是有效的 C 代码(至少对我而言):

You are unnecessarily iterating over each output and then over each monitor. So you receive a duplicate entries. You do not have to call XRRGetOutputInfo for each output, since all data you need (number of monitors) can be found in structure returned by XRRGetScreenResources. Here is the C code that works (at least for me):

#include <stdio.h>
#include <stdlib.h>
#include <X11/Xlib.h>
#include <X11/extensions/Xrandr.h>

int main(void) {
    Display *d = XOpenDisplay(getenv("DISPLAY"));
    Window   w = DefaultRootWindow(d);
    XRRScreenResources *xrrr = XRRGetScreenResources(d, w);
    XRRCrtcInfo *xrrci;
    int i;
    int ncrtc = xrrr->ncrtc;
    for (i = 0; i < ncrtc; ++i) {
        xrrci = XRRGetCrtcInfo(d, xrrr, xrrr->crtcs[i]);
        printf("%dx%d+%d+%d\n", xrrci->width, xrrci->height, xrrci->x, xrrci->y);
        XRRFreeCrtcInfo(xrrci);
    }
    XRRFreeScreenResources(xrrr);
    return 0;
}

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