obs-studio/libobs-opengl/gl-x11.c

606 lines
14 KiB
C

/******************************************************************************
Copyright (C) 2014 by Zachary Lund <admin@computerquip.com>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
******************************************************************************/
/* Version 2 of the GLX backend...
* Difference from version 1 is that we use XCB to help alleviate
* pains in a threaded environment that is prone to error.
* These errors must be readable and handled for the sake of,
* not only the users' sanity, but my own.
*
* With that said, we have more error checking capabilities...
* and not all of them are used to help simplify current code.
*
* TODO: Implement more complete error checking.
* NOTE: GLX loading functions are placed illogically
* for the sake of convenience.
*/
#include <X11/Xlib.h>
#include <X11/Xlib-xcb.h>
#include <xcb/xcb.h>
#include <stdio.h>
#include "gl-subsystem.h"
#include <glad/glad_glx.h>
static const int ctx_attribs[] = {
#ifdef _DEBUG
GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_DEBUG_BIT_ARB,
#endif
GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_CORE_PROFILE_BIT_ARB,
GLX_CONTEXT_MAJOR_VERSION_ARB, 3, GLX_CONTEXT_MINOR_VERSION_ARB, 2,
None,
};
static int ctx_pbuffer_attribs[] = {
GLX_PBUFFER_WIDTH, 2,
GLX_PBUFFER_HEIGHT, 2,
None
};
static int ctx_visual_attribs[] = {
GLX_STENCIL_SIZE, 0,
GLX_DEPTH_SIZE, 0,
GLX_BUFFER_SIZE, 32,
GLX_DOUBLEBUFFER, true,
GLX_X_RENDERABLE, true,
None
};
struct gl_windowinfo {
/* We store this value since we can fetch a lot
* of information not only concerning the config
* but the visual, and various other settings
* for the context.
*/
GLXFBConfig config;
/* Windows in X11 are defined with integers (XID).
* xcb_window_t is a define for this... they are
* compatible with Xlib as well.
*/
xcb_window_t window;
/* We can't fetch screen without a request so we cache it. */
int screen;
};
struct gl_platform {
Display *display;
GLXContext context;
GLXPbuffer pbuffer;
};
static void print_info_stuff(const struct gs_init_data *info)
{
blog( LOG_INFO,
"X and Y: %i %i\n"
"Backbuffers: %i\n"
"Color Format: %i\n"
"ZStencil Format: %i\n"
"Adapter: %i\n",
info->cx, info->cy,
info->num_backbuffers,
info->format, info->zsformat,
info->adapter
);
}
/* The following utility functions are copied verbatim from WGL code.
* GLX and WGL are more similar than most people realize. */
/* For now, only support basic 32bit formats for graphics output. */
static inline int get_color_format_bits(enum gs_color_format format)
{
switch ((uint32_t)format) {
case GS_RGBA:
return 32;
default:
return 0;
}
}
static inline int get_depth_format_bits(enum gs_zstencil_format zsformat)
{
switch ((uint32_t)zsformat) {
case GS_Z16:
return 16;
case GS_Z24_S8:
return 24;
default:
return 0;
}
}
static inline int get_stencil_format_bits(enum gs_zstencil_format zsformat)
{
switch ((uint32_t)zsformat) {
case GS_Z24_S8:
return 8;
default:
return 0;
}
}
/*
* Since we cannot take advantage of the asynchronous nature of xcb,
* all of the helper functions are synchronous but thread-safe.
*
* They check for errors and will return 0 on problems
* with the exception of when 0 is a valid return value... in which case
* read the specific function comments.
*/
/* Returns -1 on invalid screen. */
static int get_screen_num_from_xcb_screen(xcb_connection_t *xcb_conn,
xcb_screen_t *screen)
{
xcb_screen_iterator_t iter =
xcb_setup_roots_iterator(xcb_get_setup(xcb_conn));
int screen_num = 0;
for (; iter.rem; xcb_screen_next(&iter), ++screen_num)
if (iter.data == screen)
return screen_num;
return -1;
}
static xcb_screen_t *get_screen_from_root(xcb_connection_t *xcb_conn,
xcb_window_t root)
{
xcb_screen_iterator_t iter =
xcb_setup_roots_iterator(xcb_get_setup(xcb_conn));
while (iter.rem) {
if (iter.data->root == root)
return iter.data;
xcb_screen_next(&iter);
}
return 0;
}
static inline int get_screen_num_from_root(xcb_connection_t *xcb_conn,
xcb_window_t root)
{
xcb_screen_t *screen = get_screen_from_root(xcb_conn, root);
if (!screen) return -1;
return get_screen_num_from_xcb_screen(xcb_conn, screen);
}
static xcb_get_geometry_reply_t* get_window_geometry(
xcb_connection_t *xcb_conn, xcb_drawable_t drawable)
{
xcb_get_geometry_cookie_t cookie;
xcb_generic_error_t *error;
xcb_get_geometry_reply_t *reply;
cookie = xcb_get_geometry(xcb_conn, drawable);
reply = xcb_get_geometry_reply(xcb_conn, cookie, &error);
if (error) {
blog(LOG_ERROR, "Failed to fetch parent window geometry!");
free(error);
free(reply);
return 0;
}
free(error);
return reply;
}
static bool gl_context_create(struct gl_platform *plat)
{
Display *display = plat->display;
int frame_buf_config_count = 0;
GLXFBConfig *config = NULL;
GLXContext context;
bool success = false;
if (!GLAD_GLX_ARB_create_context) {
blog(LOG_ERROR, "ARB_GLX_create_context not supported!");
return false;
}
config = glXChooseFBConfig(display, DefaultScreen(display),
ctx_visual_attribs, &frame_buf_config_count);
if (!config) {
blog(LOG_ERROR, "Failed to create OpenGL frame buffer config");
return false;
}
context = glXCreateContextAttribsARB(display, config[0], NULL,
true, ctx_attribs);
if (!context) {
blog(LOG_ERROR, "Failed to create OpenGL context.");
goto error;
}
plat->context = context;
plat->display = display;
plat->pbuffer = glXCreatePbuffer(display, config[0],
ctx_pbuffer_attribs);
if (!plat->pbuffer) {
blog(LOG_ERROR, "Failed to create OpenGL pbuffer");
goto error;
}
success = true;
error:
XFree(config);
XSync(display, false);
return success;
}
static void gl_context_destroy(struct gl_platform *plat)
{
Display *display = plat->display;
glXMakeContextCurrent(display, None, None, NULL);
glXDestroyContext(display, plat->context);
bfree(plat);
}
extern struct gl_windowinfo *gl_windowinfo_create(const struct gs_init_data *info)
{
UNUSED_PARAMETER(info);
return bmalloc(sizeof(struct gl_windowinfo));
}
extern void gl_windowinfo_destroy(struct gl_windowinfo *info)
{
UNUSED_PARAMETER(info);
bfree(info);
}
static Display *open_windowless_display(void)
{
Display *display = XOpenDisplay(NULL);
xcb_connection_t *xcb_conn;
xcb_screen_iterator_t screen_iterator;
xcb_screen_t *screen;
int screen_num;
if (!display) {
blog(LOG_ERROR, "Unable to open new X connection!");
return NULL;
}
xcb_conn = XGetXCBConnection(display);
if (!xcb_conn) {
blog(LOG_ERROR, "Unable to get XCB connection to main display");
goto error;
}
screen_iterator = xcb_setup_roots_iterator(xcb_get_setup(xcb_conn));
screen = screen_iterator.data;
if (!screen) {
blog(LOG_ERROR, "Unable to get screen root");
goto error;
}
screen_num = get_screen_num_from_root(xcb_conn, screen->root);
if (screen_num == -1) {
blog(LOG_ERROR, "Unable to get screen number from root");
goto error;
}
if (!gladLoadGLX(display, screen_num)) {
blog(LOG_ERROR, "Unable to load GLX entry functions.");
goto error;
}
return display;
error:
if (display)
XCloseDisplay(display);
return NULL;
}
static int x_error_handler(Display *display, XErrorEvent *error)
{
char str[512];
XGetErrorText(display, error->error_code, str, sizeof(str));
blog(LOG_ERROR, "X Error: %s", str);
return 0;
}
extern struct gl_platform *gl_platform_create(gs_device_t *device,
uint32_t adapter)
{
/* There's some trickery here... we're mixing libX11, xcb, and GLX
For an explanation see here: http://xcb.freedesktop.org/MixingCalls/
Essentially, GLX requires Xlib. Everything else we use xcb. */
struct gl_platform * plat = bmalloc(sizeof(struct gl_platform));
Display * display = open_windowless_display();
if (!display) {
goto fail_display_open;
}
XSetEventQueueOwner(display, XCBOwnsEventQueue);
XSetErrorHandler(x_error_handler);
/* We assume later that cur_swap is already set. */
device->plat = plat;
plat->display = display;
if (!gl_context_create(plat)) {
blog(LOG_ERROR, "Failed to create context!");
goto fail_context_create;
}
if (!glXMakeContextCurrent(plat->display, plat->pbuffer, plat->pbuffer,
plat->context)) {
blog(LOG_ERROR, "Failed to make context current.");
goto fail_make_current;
}
if (!gladLoadGL()) {
blog(LOG_ERROR, "Failed to load OpenGL entry functions.");
goto fail_load_gl;
}
blog(LOG_INFO, "OpenGL version: %s\n", glGetString(GL_VERSION));
goto success;
fail_make_current:
gl_context_destroy(plat);
fail_context_create:
fail_load_gl:
XCloseDisplay(display);
fail_display_open:
bfree(plat);
plat = NULL;
success:
UNUSED_PARAMETER(adapter);
return plat;
}
extern void gl_platform_destroy(struct gl_platform *plat)
{
if (!plat) /* In what case would platform be invalid here? */
return;
gl_context_destroy(plat);
}
extern bool gl_platform_init_swapchain(struct gs_swap_chain *swap)
{
Display *display = swap->device->plat->display;
xcb_connection_t *xcb_conn = XGetXCBConnection(display);
xcb_window_t wid = xcb_generate_id(xcb_conn);
xcb_window_t parent = swap->info.window.id;
xcb_get_geometry_reply_t *geometry =
get_window_geometry(xcb_conn, parent);
bool status = false;
int screen_num;
int visual;
GLXFBConfig *fb_config;
if (!geometry) goto fail_geometry_request;
screen_num = get_screen_num_from_root(xcb_conn, geometry->root);
if (screen_num == -1) {
goto fail_screen;
}
/* ...fetch the best match... */
{
int num_configs;
fb_config = glXChooseFBConfig(display, screen_num,
ctx_visual_attribs, &num_configs);
if (!fb_config || !num_configs) {
blog(LOG_ERROR, "Failed to find FBConfig!");
goto fail_fb_config;
}
}
/* ...then fetch matching visual info for xcb. */
{
int error = glXGetFBConfigAttrib(display, fb_config[0], GLX_VISUAL_ID, &visual);
if (error) {
blog(LOG_ERROR, "Bad call to GetFBConfigAttrib!");
goto fail_visual_id;
}
}
xcb_colormap_t colormap = xcb_generate_id(xcb_conn);
uint32_t mask = XCB_CW_BORDER_PIXEL | XCB_CW_COLORMAP;
uint32_t mask_values[] = { 0, colormap, 0 };
xcb_create_colormap(xcb_conn,
XCB_COLORMAP_ALLOC_NONE,
colormap,
parent,
visual
);
xcb_create_window(
xcb_conn, 24 /* Hardcoded? */,
wid, parent,
0, 0,
geometry->width,
geometry->height,
0, 0,
visual, mask, mask_values
);
swap->wi->config = fb_config[0];
swap->wi->window = wid;
xcb_map_window(xcb_conn, wid);
XFree(fb_config);
status = true;
goto success;
fail_visual_id:
XFree(fb_config);
fail_fb_config:
fail_screen:
fail_geometry_request:
success:
free(geometry);
return status;
}
extern void gl_platform_cleanup_swapchain(struct gs_swap_chain *swap)
{
UNUSED_PARAMETER(swap);
/* Really nothing to clean up? */
}
extern void device_enter_context(gs_device_t *device)
{
GLXContext context = device->plat->context;
Display *display = device->plat->display;
if (device->cur_swap) {
XID window = device->cur_swap->wi->window;
if (!glXMakeContextCurrent(display, window, window, context)) {
blog(LOG_ERROR, "Failed to make context current.");
}
} else {
GLXPbuffer pbuf = device->plat->pbuffer;
if (!glXMakeContextCurrent(display, pbuf, pbuf, context)) {
blog(LOG_ERROR, "Failed to make context current.");
}
}
}
extern void device_leave_context(gs_device_t *device)
{
Display *display = device->plat->display;
if (!glXMakeContextCurrent(display, None, None, NULL)) {
blog(LOG_ERROR, "Failed to reset current context.");
}
}
extern void gl_getclientsize(const struct gs_swap_chain *swap,
uint32_t *width, uint32_t *height)
{
xcb_connection_t *xcb_conn = XGetXCBConnection(swap->device->plat->display);
xcb_window_t window = swap->wi->window;
xcb_get_geometry_reply_t *geometry = get_window_geometry(xcb_conn, window);
*width = geometry->width;
*height = geometry->height;
free(geometry);
}
extern void gl_update(gs_device_t *device)
{
Display *display = device->plat->display;
xcb_window_t window = device->cur_swap->wi->window;
uint32_t values[] = {
device->cur_swap->info.cx,
device->cur_swap->info.cy
};
xcb_configure_window(
XGetXCBConnection(display), window,
XCB_CONFIG_WINDOW_WIDTH | XCB_CONFIG_WINDOW_HEIGHT,
values
);
}
extern void device_load_swapchain(gs_device_t *device, gs_swapchain_t *swap)
{
if (device->cur_swap == swap)
return;
Display *dpy = device->plat->display;
GLXContext ctx = device->plat->context;
device->cur_swap = swap;
if (swap) {
XID window = swap->wi->window;
if (!glXMakeContextCurrent(dpy, window, window, ctx)) {
blog(LOG_ERROR, "Failed to make context current.");
}
} else {
GLXPbuffer pbuf = device->plat->pbuffer;
if (!glXMakeContextCurrent(dpy, pbuf, pbuf, ctx)) {
blog(LOG_ERROR, "Failed to make context current.");
}
}
}
enum swap_type {
SWAP_TYPE_NORMAL,
SWAP_TYPE_EXT,
SWAP_TYPE_MESA,
SWAP_TYPE_SGI,
};
extern void device_present(gs_device_t *device)
{
static bool initialized = false;
static enum swap_type swap_type = SWAP_TYPE_NORMAL;
Display *display = device->plat->display;
XID window = device->cur_swap->wi->window;
if (!initialized) {
if (GLAD_GLX_EXT_swap_control)
swap_type = SWAP_TYPE_EXT;
else if (GLAD_GLX_MESA_swap_control)
swap_type = SWAP_TYPE_MESA;
else if (GLAD_GLX_SGI_swap_control)
swap_type = SWAP_TYPE_SGI;
initialized = true;
}
xcb_connection_t *xcb_conn = XGetXCBConnection(display);
xcb_generic_event_t *xcb_event;
while((xcb_event = xcb_poll_for_event(xcb_conn))) {
/* TODO: Handle XCB events. */
free(xcb_event);
}
switch (swap_type) {
case SWAP_TYPE_EXT: glXSwapIntervalEXT(display, window, 0); break;
case SWAP_TYPE_MESA: glXSwapIntervalMESA(0); break;
case SWAP_TYPE_SGI: glXSwapIntervalSGI(0); break;
case SWAP_TYPE_NORMAL:;
}
glXSwapBuffers(display, window);
}