picom/src/vsync.c

205 lines
4.6 KiB
C

// SPDX-License-Identifier: MPL-2.0
// Copyright (c) Yuxuan Shui <yshuiv7@gmail.com>
/// Function pointers to init VSync modes.
#include "common.h"
#include "log.h"
#ifdef CONFIG_OPENGL
#include "backend/gl/glx.h"
#include "opengl.h"
#endif
#ifdef CONFIG_VSYNC_DRM
#include <drm.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#endif
#include "config.h"
#include "vsync.h"
#ifdef CONFIG_VSYNC_DRM
/**
* Wait for next VSync, DRM method.
*
* Stolen from:
* https://github.com/MythTV/mythtv/blob/master/mythtv/libs/libmythtv/vsync.cpp
*/
static int vsync_drm_wait(session_t *ps) {
int ret = -1;
drm_wait_vblank_t vbl;
vbl.request.type = _DRM_VBLANK_RELATIVE, vbl.request.sequence = 1;
do {
ret = ioctl(ps->drm_fd, DRM_IOCTL_WAIT_VBLANK, &vbl);
vbl.request.type &= ~(uint)_DRM_VBLANK_RELATIVE;
} while (ret && errno == EINTR);
if (ret)
log_error("VBlank ioctl did not work, unimplemented in this drmver?");
return ret;
}
/**
* Initialize DRM VSync.
*
* @return true for success, false otherwise
*/
static bool vsync_drm_init(session_t *ps) {
// Should we always open card0?
if (ps->drm_fd < 0 && (ps->drm_fd = open("/dev/dri/card0", O_RDWR)) < 0) {
log_error("Failed to open device.");
return false;
}
if (vsync_drm_wait(ps))
return false;
return true;
}
#endif
#ifdef CONFIG_OPENGL
/**
* Initialize OpenGL VSync.
*
* Stolen from:
* http://git.tuxfamily.org/?p=ccm/cairocompmgr.git;a=commitdiff;h=efa4ceb97da501e8630ca7f12c99b1dce853c73e
* Possible original source: http://www.inb.uni-luebeck.de/~boehme/xvideo_sync.html
*
* @return true for success, false otherwise
*/
static bool vsync_opengl_init(session_t *ps) {
if (!ensure_glx_context(ps))
return false;
return glxext.has_GLX_SGI_video_sync;
}
static bool vsync_opengl_oml_init(session_t *ps) {
if (!ensure_glx_context(ps))
return false;
return glxext.has_GLX_OML_sync_control;
}
static inline bool vsync_opengl_swc_swap_interval(session_t *ps, int interval) {
if (glxext.has_GLX_MESA_swap_control)
return glXSwapIntervalMESA((uint)interval) == 0;
else if (glxext.has_GLX_SGI_swap_control)
return glXSwapIntervalSGI(interval) == 0;
else if (glxext.has_GLX_EXT_swap_control) {
GLXDrawable d = glXGetCurrentDrawable();
if (d == None) {
// We don't have a context??
return false;
}
glXSwapIntervalEXT(ps->dpy, glXGetCurrentDrawable(), interval);
return true;
}
return false;
}
static bool vsync_opengl_swc_init(session_t *ps) {
if (!bkend_use_glx(ps)) {
log_error("OpenGL swap control requires the GLX backend.");
return false;
}
if (!vsync_opengl_swc_swap_interval(ps, 1)) {
log_error("Failed to load a swap control extension.");
return false;
}
return true;
}
/**
* Wait for next VSync, OpenGL method.
*/
static int vsync_opengl_wait(session_t *ps) {
unsigned vblank_count = 0;
glXGetVideoSyncSGI(&vblank_count);
glXWaitVideoSyncSGI(2, (vblank_count + 1) % 2, &vblank_count);
return 0;
}
/**
* Wait for next VSync, OpenGL OML method.
*
* https://mail.gnome.org/archives/clutter-list/2012-November/msg00031.html
*/
static int vsync_opengl_oml_wait(session_t *ps) {
int64_t ust = 0, msc = 0, sbc = 0;
glXGetSyncValuesOML(ps->dpy, ps->reg_win, &ust, &msc, &sbc);
glXWaitForMscOML(ps->dpy, ps->reg_win, 0, 2, (msc + 1) % 2, &ust, &msc, &sbc);
return 0;
}
#endif
/**
* Initialize current VSync method.
*/
bool vsync_init(session_t *ps) {
#ifdef CONFIG_OPENGL
if (bkend_use_glx(ps)) {
// Mesa turns on swap control by default, undo that
vsync_opengl_swc_swap_interval(ps, 0);
}
#endif
#ifdef CONFIG_VSYNC_DRM
log_warn("The DRM vsync method is deprecated, please don't enable it.");
#endif
if (!ps->o.vsync) {
return true;
}
#ifdef CONFIG_OPENGL
if (bkend_use_glx(ps)) {
if (!vsync_opengl_swc_init(ps)) {
return false;
}
ps->vsync_wait = NULL; // glXSwapBuffers will automatically wait
// for vsync, we don't need to do anything.
return true;
}
#endif
// Oh no, we are not using glx backend.
// Throwing things at wall.
#ifdef CONFIG_OPENGL
if (vsync_opengl_oml_init(ps)) {
log_info("Using the opengl-oml vsync method");
ps->vsync_wait = vsync_opengl_oml_wait;
return true;
}
if (vsync_opengl_init(ps)) {
log_info("Using the opengl vsync method");
ps->vsync_wait = vsync_opengl_wait;
return true;
}
#endif
#ifdef CONFIG_VSYNC_DRM
if (vsync_drm_init(ps)) {
log_info("Using the drm vsync method");
ps->vsync_wait = vsync_drm_wait;
return true;
}
#endif
log_error("No supported vsync method found for this backend");
return false;
}