我曾尝试使用Xlib、XF86VidMode和OpenGL编写简单的图形,但遇到了两个问题:
虽然我可以使用RandR切换视频模式,但我想使用xcb版本,但它没有生效。我抄袭了@datenwolf的xcb示例,但某种程度上xcb_randr_get_screen_info_reply没有生效。它应该返回一个指向结构体的指针,该结构体后面跟着一个屏幕维度数组(毫米维度不正确),然后是刷新率数据。刷新率数据是垃圾,大多数是零。我做错了什么?
因此,我的输出结果是:
- Xlib似乎没有类似于WM_TIMER的东西,所以我编写了一个SIGALRM处理程序来发送消息以解除消息循环的阻塞状态。但是,由于这种用法完全不安全,所以程序会在一段时间后挂起。因此,我尝试了在xcb中重新编码。
- 使用XF86VidMode非常麻烦,而且结果不理想,所以我切换到了RandR。
虽然我可以使用RandR切换视频模式,但我想使用xcb版本,但它没有生效。我抄袭了@datenwolf的xcb示例,但某种程度上xcb_randr_get_screen_info_reply没有生效。它应该返回一个指向结构体的指针,该结构体后面跟着一个屏幕维度数组(毫米维度不正确),然后是刷新率数据。刷新率数据是垃圾,大多数是零。我做错了什么?
/*
gcc rrxcb.c -lxcb-randr -lxcb -lX11 -lX11-xcb -lGL -orrxcb
*/
#include <xcb/randr.h>
#include <stdio.h>
#include <X11/Xlib.h>
#include <X11/Xlib-xcb.h>
#include <xcb/xcb.h>
#include <GL/glx.h>
#include <unistd.h>
void screen_from_Xlib_Display(
Display * const display,
xcb_connection_t *connection,
int * const out_screen_num,
xcb_screen_t ** const out_screen)
{
xcb_screen_iterator_t screen_iter = xcb_setup_roots_iterator(xcb_get_setup(connection));
int screen_num = DefaultScreen(display);
while( screen_iter.rem && screen_num > 0 ) {
xcb_screen_next(&screen_iter);
--screen_num;
}
*out_screen_num = screen_num;
*out_screen = screen_iter.data;
}
int main()
{
Display *display;
xcb_connection_t *connection;
xcb_window_t win;
const int GLX_TRUE = True;
int attrib_list[] = {GLX_X_RENDERABLE,GLX_TRUE,
GLX_DRAWABLE_TYPE,GLX_WINDOW_BIT,
GLX_RENDER_TYPE,GLX_RGBA_BIT,
GLX_CONFIG_CAVEAT,GLX_NONE,
GLX_DOUBLEBUFFER,GLX_TRUE,
GLX_BUFFER_SIZE,32,
GLX_DEPTH_SIZE,24,
GLX_STENCIL_SIZE,8,
0};
GLXFBConfig *FBConfigs;
int nelements;
GLXFBConfig fb_config;
XVisualInfo *visual;
int visualID;
GLXContext context;
xcb_colormap_t colormap;
xcb_void_cookie_t create_color;
xcb_void_cookie_t create_win;
const uint32_t eventmask = XCB_EVENT_MASK_EXPOSURE | XCB_EVENT_MASK_KEY_PRESS;
const uint32_t valuemask = XCB_CW_EVENT_MASK | XCB_CW_COLORMAP;
uint32_t valuelist[] = {eventmask,colormap};
xcb_randr_get_screen_info_cookie_t screen_info;
xcb_randr_get_screen_info_reply_t *reply;
int screen_num;
xcb_screen_t *screen;
xcb_generic_error_t *error;
xcb_randr_screen_size_t *sizes;
int sizes_length;
xcb_randr_refresh_rates_iterator_t rates_iter;
uint16_t *rates;
int rates_length;
int i;
/* Open Xlib Display */
display = XOpenDisplay(NULL);
printf("display = %p\n",display);
connection = XGetXCBConnection(display);
printf("connection = %p\n",connection);
XSetEventQueueOwner(display,XCBOwnsEventQueue);
win = xcb_generate_id(connection);
printf("win = %d\n",win);
screen_from_Xlib_Display(display,connection,&screen_num,&screen);
printf("screen_num = %d\n",screen_num);
printf("screen->root = %d\n",screen->root);
FBConfigs = glXChooseFBConfig(display,screen_num,attrib_list,
&nelements);
printf("FBConfig = %p\n",FBConfigs);
printf("nelements = %d\n",nelements);
fb_config = FBConfigs[0];
visual = glXGetVisualFromFBConfig(display,fb_config);
printf("visual = %p\n",visual);
visualID = visual->visualid;
printf("visualID = %d\n",visualID);
context = glXCreateNewContext(display,fb_config,GLX_RGBA_TYPE,
0,True);
printf("context = %p\n",context);
colormap = xcb_generate_id(connection);
printf("colormap = %d\n",colormap);
create_color = xcb_create_colormap_checked(connection,
XCB_COLORMAP_ALLOC_NONE,colormap,screen->root,visualID);
printf("create_color.sequence = %d\n",create_color.sequence);
error = xcb_request_check(connection,create_color);
printf("error = %p\n",error);
create_win = xcb_create_window_checked(connection,
XCB_COPY_FROM_PARENT,win, screen->root,0,0,640,480,2,
XCB_WINDOW_CLASS_INPUT_OUTPUT,visualID,valuemask,valuelist);
printf("create_win.sequence = %d\n",create_win.sequence);
error = xcb_request_check(connection,create_win);
printf("error = %p\n",error);
screen_info = xcb_randr_get_screen_info_unchecked(connection, screen->root);
printf("screen_info.sequence = %d\n",screen_info.sequence);
reply = xcb_randr_get_screen_info_reply(connection,screen_info,
NULL);
printf("reply = %p\n",reply);
printf("reply->response_type = %d\n",reply->response_type);
printf("reply->rotations = %d\n",reply->rotations);
printf("reply->sequence = %d\n",reply->sequence);
printf("reply->length = %d\n",reply->length);
printf("reply->nSizes = %d\n",reply->nSizes);
printf("reply->sizeID = %d\n",reply->sizeID);
printf("reply->rotation = %d\n",reply->rotation);
printf("reply->rate = %d\n",reply->rate);
printf("reply->nInfo = %d\n",reply->nInfo);
printf("reply+1 = %p\n",reply+1);
sizes = xcb_randr_get_screen_info_sizes(reply);
printf("sizes = %p\n",sizes);
sizes_length = xcb_randr_get_screen_info_sizes_length(reply);
printf("sizes_length = %d\n",sizes_length);
rates_iter = xcb_randr_get_screen_info_rates_iterator(reply);
printf("rates_iter.data = %p\n",rates_iter.data);
printf("rates_iter.rem = %d\n",rates_iter.rem);
printf("rates_iter.index = %d\n",rates_iter.index);
for( ; rates_iter.rem; xcb_randr_refresh_rates_next(&rates_iter))
{
rates = xcb_randr_refresh_rates_rates(rates_iter.data);
printf("rates = %p\n",rates);
rates_length =
xcb_randr_refresh_rates_rates_length(rates_iter.data);
printf("rates_length = %d\n",rates_length);
printf("rates[0] = %d\n",rates[0]);
/*
for(i = 0; i < rates_length; i++)
{
printf("%d%c",rates[i],(i==rates_length-1)?'\n':' ');
}
*/
}
for(i = 0; i < sizes_length; i++)
{
printf("%d %d %d %d %d\n",i,sizes[i].width,sizes[i].height,sizes[i].mwidth,sizes[i].mheight);
}
return 0;
}
因此,我的输出结果是:
display = 0x563687942010
connection = 0x563687943410
win = 54525954
screen_num = 0
screen->root = 241
FBConfig = 0x563687951b20
nelements = 8
visual = 0x563687951d30
visualID = 33
context = 0x563687951680
colormap = 54525956
create_color.sequence = 26
error = (nil)
create_win.sequence = 28
error = (nil)
screen_info.sequence = 31
reply = 0x563687abde30
reply->response_type = 1
reply->rotations = 63
reply->sequence = 31
reply->length = 36
reply->nSizes = 18
reply->sizeID = 1
reply->rotation = 1
reply->rate = 30
reply->nInfo = 53
reply+1 = 0x563687abde50
sizes = 0x563687abde50
sizes_length = 18
rates_iter.data = 0x563687abdee0
rates_iter.rem = 35
rates_iter.index = 176
rates = 0x563687abdee2
rates_length = 0
rates[0] = 0
rates = 0x563687abdee4
rates_length = 0
rates[0] = 0
rates = 0x563687abdee6
rates_length = 0
...
rates = 0x563687add7a8
rates_length = 0
rates[0] = 0
0 4096 2160 1872 1053
1 3840 2160 1872 1053
2 1920 1080 1872 1053
3 1680 1050 1872 1053
4 1600 900 1872 1053
5 1280 1024 1872 1053
6 1440 900 1872 1053
7 1366 768 1872 1053
8 1280 800 1872 1053
9 1152 864 1872 1053
10 1280 720 1872 1053
11 1024 768 1872 1053
12 832 624 1872 1053
13 800 600 1872 1053
14 720 576 1872 1053
15 720 480 1872 1053
16 640 480 1872 1053
17 720 400 1872 1053
有人能发现我做错了什么吗?