Commit a15624dc authored by Roman Gilg's avatar Roman Gilg
Browse files

Revert "[platforms/x11/standalone] Remove SGI swap control and video sync"

This reverts commit 285adc19.

See: https://mail.kde.org/pipermail/kwin/2020-January/002999.html
parent bcf64af4
......@@ -212,6 +212,7 @@ void GlxBackend::init()
m_haveMESACopySubBuffer = hasExtension(QByteArrayLiteral("GLX_MESA_copy_sub_buffer"));
m_haveMESASwapControl = hasExtension(QByteArrayLiteral("GLX_MESA_swap_control"));
m_haveEXTSwapControl = hasExtension(QByteArrayLiteral("GLX_EXT_swap_control"));
m_haveSGISwapControl = hasExtension(QByteArrayLiteral("GLX_SGI_swap_control"));
// only enable Intel swap event if env variable is set, see BUG 342582
m_haveINTELSwapEvent = hasExtension(QByteArrayLiteral("GLX_INTEL_swap_event"))
&& qgetenv("KWIN_USE_INTEL_SWAP_EVENT") == QByteArrayLiteral("1");
......@@ -221,7 +222,7 @@ void GlxBackend::init()
glXSelectEvent(display(), glxWindow, GLX_BUFFER_SWAP_COMPLETE_INTEL_MASK);
}
haveSwapInterval = m_haveMESASwapControl || m_haveEXTSwapControl;
haveSwapInterval = m_haveMESASwapControl || m_haveEXTSwapControl || m_haveSGISwapControl;
setSupportsBufferAge(false);
......@@ -233,15 +234,23 @@ void GlxBackend::init()
}
setSyncsToVBlank(false);
setBlocksForRetrace(true);
setBlocksForRetrace(false);
haveWaitSync = false;
const bool wantSync = options->glPreferBufferSwap() != Options::NoSwapEncourage;
if (wantSync && glXIsDirect(display(), ctx)) {
if (haveSwapInterval) { // glXSwapInterval is preferred being more reliable
setSwapInterval(1);
setSyncsToVBlank(true);
} else {
qCWarning(KWIN_X11STANDALONE) << "NO VSYNC! glSwapInterval is not supported";
}
} else if (hasExtension(QByteArrayLiteral("GLX_SGI_video_sync"))) {
unsigned int sync;
if (glXGetVideoSyncSGI(&sync) == 0 && glXWaitVideoSyncSGI(1, 0, &sync) == 0) {
setSyncsToVBlank(true);
setBlocksForRetrace(true);
haveWaitSync = true;
} else
qCWarning(KWIN_X11STANDALONE) << "NO VSYNC! glXSwapInterval is not supported, glXWaitVideoSync is supported but broken";
} else
qCWarning(KWIN_X11STANDALONE) << "NO VSYNC! neither glSwapInterval nor glXWaitVideoSync are supported";
} else {
// disable v-sync (if possible)
setSwapInterval(0);
......@@ -678,6 +687,25 @@ void GlxBackend::setSwapInterval(int interval)
glXSwapIntervalEXT(display(), glxWindow, interval);
else if (m_haveMESASwapControl)
glXSwapIntervalMESA(interval);
else if (m_haveSGISwapControl)
glXSwapIntervalSGI(interval);
}
void GlxBackend::waitSync()
{
// NOTE that vsync has no effect with indirect rendering
if (haveWaitSync) {
uint sync;
#if 0
// TODO: why precisely is this important?
// the sync counter /can/ perform multiple steps during glXGetVideoSync & glXWaitVideoSync
// but this only leads to waiting for two frames??!?
glXGetVideoSync(&sync);
glXWaitVideoSync(2, (sync + 1) % 2, &sync);
#else
glXWaitVideoSyncSGI(1, 0, &sync);
#endif
}
}
void GlxBackend::present()
......@@ -696,6 +724,7 @@ void GlxBackend::present()
if (haveSwapInterval) {
glXSwapBuffers(display(), glxWindow);
} else {
waitSync();
glXSwapBuffers(display(), glxWindow);
}
if (supportsBufferAge()) {
......
......@@ -86,6 +86,7 @@ private:
bool initBuffer();
bool checkVersion();
void initExtensions();
void waitSync();
bool initRenderingContext();
bool initFbConfig();
void initVisualDepthHashTable();
......@@ -112,8 +113,10 @@ private:
bool m_haveMESACopySubBuffer = false;
bool m_haveMESASwapControl = false;
bool m_haveEXTSwapControl = false;
bool m_haveSGISwapControl = false;
bool m_haveINTELSwapEvent = false;
bool haveSwapInterval = false;
bool haveWaitSync = false;
Display *m_x11Display;
friend class GlxTexture;
};
......
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