EglHwcomposerBackend::EglHwcomposerBackend(HwcomposerBackend *backend)
: AbstractEglBackend()
, m_backend(backend)
{
// EGL is always direct rendering
setIsDirectRendering(true);
setSyncsToVBlank(true);
setBlocksForRetrace(true);
}
void GlxBackend::present()
{
if (lastDamage().isEmpty())
return;
const QSize &screenSize = screens()->size();
const QRegion displayRegion(0, 0, screenSize.width(), screenSize.height());
const bool fullRepaint = supportsBufferAge() || (lastDamage() == displayRegion);
if (fullRepaint) {
if (m_haveINTELSwapEvent)
Compositor::self()->aboutToSwapBuffers();
if (haveSwapInterval) {
if (gs_tripleBufferNeedsDetection) {
glXWaitGL();
m_swapProfiler.begin();
}
glXSwapBuffers(display(), glxWindow);
if (gs_tripleBufferNeedsDetection) {
glXWaitGL();
if (char result = m_swapProfiler.end()) {
gs_tripleBufferUndetected = gs_tripleBufferNeedsDetection = false;
if (result == 'd' && GLPlatform::instance()->driver() == Driver_NVidia) {
// TODO this is a workaround, we should get __GL_YIELD set before libGL checks it
if (qstrcmp(qgetenv("__GL_YIELD"), "USLEEP")) {
options->setGlPreferBufferSwap(0);
setSwapInterval(0);
result = 0; // hint proper behavior
qCWarning(KWIN_CORE) << "\nIt seems you are using the nvidia driver without triple buffering\n"
"You must export __GL_YIELD=\"USLEEP\" to prevent large CPU overhead on synced swaps\n"
"Preferably, enable the TripleBuffer Option in the xorg.conf Device\n"
"For this reason, the tearing prevention has been disabled.\n"
"See https://bugs.kde.org/show_bug.cgi?id=322060\n";
}
}
setBlocksForRetrace(result == 'd');
}
} else if (blocksForRetrace()) {
// at least the nvidia blob manages to swap async, ie. return immediately on double
// buffering - what messes our timing calculation and leads to laggy behavior #346275
glXWaitGL();
}
} else {
waitSync();
glXSwapBuffers(display(), glxWindow);
}
if (supportsBufferAge()) {
glXQueryDrawable(display(), glxWindow, GLX_BACK_BUFFER_AGE_EXT, (GLuint *) &m_bufferAge);
}
} else if (m_haveMESACopySubBuffer) {
foreach (const QRect & r, lastDamage().rects()) {
// convert to OpenGL coordinates
int y = screenSize.height() - r.y() - r.height();
glXCopySubBufferMESA(display(), glxWindow, r.x(), y, r.width(), r.height());
}
} else { // Copy Pixels (horribly slow on Mesa)
void EglOnXBackend::present()
{
if (lastDamage().isEmpty())
return;
const QRegion displayRegion(0, 0, displayWidth(), displayHeight());
const bool fullRepaint = supportsBufferAge() || (lastDamage() == displayRegion);
if (fullRepaint || !surfaceHasSubPost) {
if (gs_tripleBufferNeedsDetection) {
eglWaitGL();
m_swapProfiler.begin();
}
// the entire screen changed, or we cannot do partial updates (which implies we enabled surface preservation)
eglSwapBuffers(dpy, surface);
if (gs_tripleBufferNeedsDetection) {
eglWaitGL();
if (char result = m_swapProfiler.end()) {
gs_tripleBufferUndetected = gs_tripleBufferNeedsDetection = false;
if (result == 'd' && GLPlatform::instance()->driver() == Driver_NVidia) {
// TODO this is a workaround, we should get __GL_YIELD set before libGL checks it
if (qstrcmp(qgetenv("__GL_YIELD"), "USLEEP")) {
options->setGlPreferBufferSwap(0);
eglSwapInterval(dpy, 0);
qWarning() << "\nIt seems you are using the nvidia driver without triple buffering\n"
"You must export __GL_YIELD=\"USLEEP\" to prevent large CPU overhead on synced swaps\n"
"Preferably, enable the TripleBuffer Option in the xorg.conf Device\n"
"For this reason, the tearing prevention has been disabled.\n"
"See https://bugs.kde.org/show_bug.cgi?id=322060\n";
}
}
setBlocksForRetrace(result == 'd');
}
}
if (supportsBufferAge()) {
eglQuerySurface(dpy, surface, EGL_BUFFER_AGE_EXT, &m_bufferAge);
}
} else {
// a part of the screen changed, and we can use eglPostSubBufferNV to copy the updated area
foreach (const QRect & r, lastDamage().rects()) {
eglPostSubBufferNV(dpy, surface, r.left(), displayHeight() - r.bottom() - 1, r.width(), r.height());
}
}
setLastDamage(QRegion());
if (!supportsBufferAge()) {
eglWaitGL();
xcb_flush(connection());
}
}
void GlxBackend::present()
{
if (lastDamage().isEmpty())
return;
const QRegion displayRegion(0, 0, displayWidth(), displayHeight());
const bool fullRepaint = supportsBufferAge() || (lastDamage() == displayRegion);
if (fullRepaint) {
if (haveSwapInterval) {
if (gs_tripleBufferNeedsDetection) {
glXWaitGL();
m_swapProfiler.begin();
}
glXSwapBuffers(display(), glxWindow);
if (gs_tripleBufferNeedsDetection) {
glXWaitGL();
if (char result = m_swapProfiler.end()) {
gs_tripleBufferUndetected = gs_tripleBufferNeedsDetection = false;
if (result == 'd' && GLPlatform::instance()->driver() == Driver_NVidia) {
// TODO this is a workaround, we should get __GL_YIELD set before libGL checks it
if (qstrcmp(qgetenv("__GL_YIELD"), "USLEEP")) {
options->setGlPreferBufferSwap(0);
setSwapInterval(0);
qWarning() << "\nIt seems you are using the nvidia driver without triple buffering\n"
"You must export __GL_YIELD=\"USLEEP\" to prevent large CPU overhead on synced swaps\n"
"Preferably, enable the TripleBuffer Option in the xorg.conf Device\n"
"For this reason, the tearing prevention has been disabled.\n"
"See https://bugs.kde.org/show_bug.cgi?id=322060\n";
}
}
setBlocksForRetrace(result == 'd');
}
}
} else {
waitSync();
glXSwapBuffers(display(), glxWindow);
}
if (supportsBufferAge()) {
glXQueryDrawable(display(), glxWindow, GLX_BACK_BUFFER_AGE_EXT, (GLuint *) &m_bufferAge);
}
} else if (glXCopySubBuffer) {
foreach (const QRect & r, lastDamage().rects()) {
// convert to OpenGL coordinates
int y = displayHeight() - r.y() - r.height();
glXCopySubBuffer(display(), glxWindow, r.x(), y, r.width(), r.height());
}
} else { // Copy Pixels (horribly slow on Mesa)
void EglOnXBackend::init()
{
if (!initRenderingContext()) {
setFailed(QStringLiteral("Could not initialize rendering context"));
return;
}
initEGL();
if (!hasGLExtension(QStringLiteral("EGL_KHR_image")) &&
(!hasGLExtension(QStringLiteral("EGL_KHR_image_base")) ||
!hasGLExtension(QStringLiteral("EGL_KHR_image_pixmap")))) {
setFailed(QStringLiteral("Required support for binding pixmaps to EGLImages not found, disabling compositing"));
return;
}
GLPlatform *glPlatform = GLPlatform::instance();
glPlatform->detect(EglPlatformInterface);
if (GLPlatform::instance()->driver() == Driver_Intel)
options->setUnredirectFullscreen(false); // bug #252817
options->setGlPreferBufferSwap(options->glPreferBufferSwap()); // resolve autosetting
if (options->glPreferBufferSwap() == Options::AutoSwapStrategy)
options->setGlPreferBufferSwap('e'); // for unknown drivers - should not happen
glPlatform->printResults();
initGL(EglPlatformInterface);
if (!hasGLExtension(QStringLiteral("GL_OES_EGL_image"))) {
setFailed(QStringLiteral("Required extension GL_OES_EGL_image not found, disabling compositing"));
return;
}
// check for EGL_NV_post_sub_buffer and whether it can be used on the surface
if (eglPostSubBufferNV) {
if (eglQuerySurface(dpy, surface, EGL_POST_SUB_BUFFER_SUPPORTED_NV, &surfaceHasSubPost) == EGL_FALSE) {
EGLint error = eglGetError();
if (error != EGL_SUCCESS && error != EGL_BAD_ATTRIBUTE) {
setFailed(QStringLiteral("query surface failed"));
return;
} else {
surfaceHasSubPost = EGL_FALSE;
}
}
}
setSupportsBufferAge(false);
if (hasGLExtension("EGL_EXT_buffer_age")) {
const QByteArray useBufferAge = qgetenv("KWIN_USE_BUFFER_AGE");
if (useBufferAge != "0")
setSupportsBufferAge(true);
}
setSyncsToVBlank(false);
setBlocksForRetrace(false);
gs_tripleBufferNeedsDetection = false;
m_swapProfiler.init();
if (surfaceHasSubPost) {
qDebug() << "EGL implementation and surface support eglPostSubBufferNV, let's use it";
if (options->glPreferBufferSwap() != Options::NoSwapEncourage) {
// check if swap interval 1 is supported
EGLint val;
eglGetConfigAttrib(dpy, config, EGL_MAX_SWAP_INTERVAL, &val);
if (val >= 1) {
if (eglSwapInterval(dpy, 1)) {
qDebug() << "Enabled v-sync";
setSyncsToVBlank(true);
const QByteArray tripleBuffer = qgetenv("KWIN_TRIPLE_BUFFER");
if (!tripleBuffer.isEmpty()) {
setBlocksForRetrace(qstrcmp(tripleBuffer, "0") == 0);
gs_tripleBufferUndetected = false;
}
gs_tripleBufferNeedsDetection = gs_tripleBufferUndetected;
}
} else {
qWarning() << "Cannot enable v-sync as max. swap interval is" << val;
}
} else {
// disable v-sync
eglSwapInterval(dpy, 0);
}
} else {
/* In the GLX backend, we fall back to using glCopyPixels if we have no extension providing support for partial screen updates.
* However, that does not work in EGL - glCopyPixels with glDrawBuffer(GL_FRONT); does nothing.
* Hence we need EGL to preserve the backbuffer for us, so that we can draw the partial updates on it and call
* eglSwapBuffers() for each frame. eglSwapBuffers() then does the copy (no page flip possible in this mode),
* which means it is slow and not synced to the v-blank. */
qWarning() << "eglPostSubBufferNV not supported, have to enable buffer preservation - which breaks v-sync and performance";
eglSurfaceAttrib(dpy, surface, EGL_SWAP_BEHAVIOR, EGL_BUFFER_PRESERVED);
}
}
void GlxBackend::init()
{
initGLX();
// require at least GLX 1.3
if (!hasGLXVersion(1, 3)) {
setFailed(QStringLiteral("Requires at least GLX 1.3"));
return;
}
if (!initDrawableConfigs()) {
setFailed(QStringLiteral("Could not initialize the drawable configs"));
return;
}
if (!initBuffer()) {
setFailed(QStringLiteral("Could not initialize the buffer"));
return;
}
if (!initRenderingContext()) {
setFailed(QStringLiteral("Could not initialize rendering context"));
return;
}
// Initialize OpenGL
GLPlatform *glPlatform = GLPlatform::instance();
glPlatform->detect(GlxPlatformInterface);
if (GLPlatform::instance()->driver() == Driver_Intel)
options->setUnredirectFullscreen(false); // bug #252817
options->setGlPreferBufferSwap(options->glPreferBufferSwap()); // resolve autosetting
if (options->glPreferBufferSwap() == Options::AutoSwapStrategy)
options->setGlPreferBufferSwap('e'); // for unknown drivers - should not happen
glPlatform->printResults();
initGL(GlxPlatformInterface);
// Check whether certain features are supported
haveSwapInterval = glXSwapIntervalMESA || glXSwapIntervalEXT || glXSwapIntervalSGI;
setSupportsBufferAge(false);
if (hasGLExtension("GLX_EXT_buffer_age")) {
const QByteArray useBufferAge = qgetenv("KWIN_USE_BUFFER_AGE");
if (useBufferAge != "0")
setSupportsBufferAge(true);
}
setSyncsToVBlank(false);
setBlocksForRetrace(false);
haveWaitSync = false;
gs_tripleBufferNeedsDetection = false;
m_swapProfiler.init();
const bool wantSync = options->glPreferBufferSwap() != Options::NoSwapEncourage;
if (wantSync && glXIsDirect(display(), ctx)) {
if (haveSwapInterval) { // glXSwapInterval is preferred being more reliable
setSwapInterval(1);
setSyncsToVBlank(true);
const QByteArray tripleBuffer = qgetenv("KWIN_TRIPLE_BUFFER");
if (!tripleBuffer.isEmpty()) {
setBlocksForRetrace(qstrcmp(tripleBuffer, "0") == 0);
gs_tripleBufferUndetected = false;
}
gs_tripleBufferNeedsDetection = gs_tripleBufferUndetected;
} else if (glXGetVideoSync) {
unsigned int sync;
if (glXGetVideoSync(&sync) == 0 && glXWaitVideoSync(1, 0, &sync) == 0) {
setSyncsToVBlank(true);
setBlocksForRetrace(true);
haveWaitSync = true;
} else
qWarning() << "NO VSYNC! glXSwapInterval is not supported, glXWaitVideoSync is supported but broken";
} else
qWarning() << "NO VSYNC! neither glSwapInterval nor glXWaitVideoSync are supported";
} else {
// disable v-sync (if possible)
setSwapInterval(0);
}
if (glPlatform->isVirtualBox()) {
// VirtualBox does not support glxQueryDrawable
// this should actually be in kwinglutils_funcs, but QueryDrawable seems not to be provided by an extension
// and the GLPlatform has not been initialized at the moment when initGLX() is called.
glXQueryDrawable = NULL;
}
setIsDirectRendering(bool(glXIsDirect(display(), ctx)));
qDebug() << "Direct rendering:" << isDirectRendering() << endl;
}
void GlxBackend::init()
{
initGLX();
// Require at least GLX 1.3
if (!hasGLXVersion(1, 3)) {
setFailed(QStringLiteral("Requires at least GLX 1.3"));
return;
}
initVisualDepthHashTable();
if (!initBuffer()) {
setFailed(QStringLiteral("Could not initialize the buffer"));
return;
}
if (!initRenderingContext()) {
setFailed(QStringLiteral("Could not initialize rendering context"));
return;
}
// Initialize OpenGL
GLPlatform *glPlatform = GLPlatform::instance();
glPlatform->detect(GlxPlatformInterface);
if (GLPlatform::instance()->driver() == Driver_Intel)
options->setUnredirectFullscreen(false); // bug #252817
options->setGlPreferBufferSwap(options->glPreferBufferSwap()); // resolve autosetting
if (options->glPreferBufferSwap() == Options::AutoSwapStrategy)
options->setGlPreferBufferSwap('e'); // for unknown drivers - should not happen
glPlatform->printResults();
initGL(GlxPlatformInterface);
// Check whether certain features are supported
m_haveMESACopySubBuffer = hasGLExtension(QByteArrayLiteral("GLX_MESA_copy_sub_buffer"));
m_haveMESASwapControl = hasGLExtension(QByteArrayLiteral("GLX_MESA_swap_control"));
m_haveEXTSwapControl = hasGLExtension(QByteArrayLiteral("GLX_EXT_swap_control"));
m_haveSGISwapControl = hasGLExtension(QByteArrayLiteral("GLX_SGI_swap_control"));
// only enable Intel swap event if env variable is set, see BUG 342582
m_haveINTELSwapEvent = hasGLExtension(QByteArrayLiteral("GLX_INTEL_swap_event"))
&& qgetenv("KWIN_USE_INTEL_SWAP_EVENT") == QByteArrayLiteral("1");
if (m_haveINTELSwapEvent) {
m_swapEventFilter = std::make_unique<SwapEventFilter>(window, glxWindow);
glXSelectEvent(display(), glxWindow, GLX_BUFFER_SWAP_COMPLETE_INTEL_MASK);
}
haveSwapInterval = m_haveMESASwapControl || m_haveEXTSwapControl || m_haveSGISwapControl;
setSupportsBufferAge(false);
if (hasGLExtension(QByteArrayLiteral("GLX_EXT_buffer_age"))) {
const QByteArray useBufferAge = qgetenv("KWIN_USE_BUFFER_AGE");
if (useBufferAge != "0")
setSupportsBufferAge(true);
}
setSyncsToVBlank(false);
setBlocksForRetrace(false);
haveWaitSync = false;
gs_tripleBufferNeedsDetection = false;
m_swapProfiler.init();
const bool wantSync = options->glPreferBufferSwap() != Options::NoSwapEncourage;
if (wantSync && glXIsDirect(display(), ctx)) {
if (haveSwapInterval) { // glXSwapInterval is preferred being more reliable
setSwapInterval(1);
setSyncsToVBlank(true);
const QByteArray tripleBuffer = qgetenv("KWIN_TRIPLE_BUFFER");
if (!tripleBuffer.isEmpty()) {
setBlocksForRetrace(qstrcmp(tripleBuffer, "0") == 0);
gs_tripleBufferUndetected = false;
}
gs_tripleBufferNeedsDetection = gs_tripleBufferUndetected;
} else if (hasGLExtension(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_CORE) << "NO VSYNC! glXSwapInterval is not supported, glXWaitVideoSync is supported but broken";
} else
qCWarning(KWIN_CORE) << "NO VSYNC! neither glSwapInterval nor glXWaitVideoSync are supported";
} else {
// disable v-sync (if possible)
setSwapInterval(0);
}
if (glPlatform->isVirtualBox()) {
// VirtualBox does not support glxQueryDrawable
// this should actually be in kwinglutils_funcs, but QueryDrawable seems not to be provided by an extension
// and the GLPlatform has not been initialized at the moment when initGLX() is called.
glXQueryDrawable = NULL;
}
setIsDirectRendering(bool(glXIsDirect(display(), ctx)));
qCDebug(KWIN_CORE) << "Direct rendering:" << isDirectRendering();
}
