kwin/plugins/platforms/x11/standalone/glxbackend.cpp
Erik Kurzinger 22a441e071 [platforms/x11] Force glXSwapBuffers to block with NVIDIA driver
Summary:
The NVIDIA implementation of glXSwapBuffers will, by default, queue up
to two frames for presentation before blocking. KWin's compositor,
however, assumes that calls to glXSwapBuffers will always block until
the next vblank when rendering double buffered. This assumption isn't
valid, as glXSwapBuffers is specified as being an implicit glFlush,
not an implicit glFinish, and so it isn't required to block. When this
assumption is violated, KWin's frame timing logic will
break. Specifically, there will be extraneous calls to
setCompositeTimer with a waitTime of 0 after the non-blocking buffer
swaps, dramatically reducing desktop responsiveness. To remedy this,
a call to glXWaitGL was added by Thomas Luebking after glXSwapBuffers
in 2015 (see bug 346275, commit
8bea96d701). That glXWaitGL call is
equivalent to a glFinish call in direct rendering, so it was a good
way to make glXSwapBuffers behave as though it implied a glFinish
call.

However, the NVIDIA driver will by default do a busy wait in glFinish,
for reduced latency. Therefore that change dramatically increased CPU
usage. GL_YIELD can be set to USLEEP (case insensitive) to change
the behavior and use usleep instead. When using the NVIDIA driver,
KWin will disable vsync entirely if GL_YIELD isn't set to USLEEP
(case sensitive, a bug in KWin).

However, the NVIDIA driver supports another environment variable,
__GL_MaxFramesAllowed, which can be used to control how many frames
may be queued by glXSwapBuffers. If this is set to 1 the function
will always block until retrace, in line with KWin's expectations.
This allows the now-unnecessary call to glXWaitGL to be removed along
with the logic to conditionally disable vsync, providing a better
experience on NVIDIA hardware.

Reviewers: #kwin, davidedmundson, zzag

Reviewed By: #kwin, davidedmundson, zzag

Subscribers: kwin, davidedmundson, zzag

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D19867
2019-03-20 09:56:05 -07:00

928 lines
30 KiB
C++

/********************************************************************
KWin - the KDE window manager
This file is part of the KDE project.
Copyright (C) 2006 Lubos Lunak <l.lunak@kde.org>
Copyright (C) 2012 Martin Gräßlin <mgraesslin@kde.org>
Based on glcompmgr code by Felix Bellaby.
Using code from Compiz and Beryl.
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/>.
*********************************************************************/
// own
#include "glxbackend.h"
#include "logging.h"
#include "glx_context_attribute_builder.h"
// kwin
#include "options.h"
#include "overlaywindow.h"
#include "composite.h"
#include "platform.h"
#include "scene.h"
#include "screens.h"
#include "xcbutils.h"
#include "texture.h"
// kwin libs
#include <kwinglplatform.h>
#include <kwinglutils.h>
#include <kwinxrenderutils.h>
// Qt
#include <QDebug>
#include <QOpenGLContext>
#include <QX11Info>
// system
#include <unistd.h>
#include <deque>
#include <algorithm>
#if HAVE_DL_LIBRARY
#include <dlfcn.h>
#endif
#include <assert.h>
#ifndef XCB_GLX_BUFFER_SWAP_COMPLETE
#define XCB_GLX_BUFFER_SWAP_COMPLETE 1
typedef struct xcb_glx_buffer_swap_complete_event_t {
uint8_t response_type; /**< */
uint8_t pad0; /**< */
uint16_t sequence; /**< */
uint16_t event_type; /**< */
uint8_t pad1[2]; /**< */
xcb_glx_drawable_t drawable; /**< */
uint32_t ust_hi; /**< */
uint32_t ust_lo; /**< */
uint32_t msc_hi; /**< */
uint32_t msc_lo; /**< */
uint32_t sbc; /**< */
} xcb_glx_buffer_swap_complete_event_t;
#endif
#include <tuple>
#include <memory>
namespace KWin
{
SwapEventFilter::SwapEventFilter(xcb_drawable_t drawable, xcb_glx_drawable_t glxDrawable)
: X11EventFilter(Xcb::Extensions::self()->glxEventBase() + XCB_GLX_BUFFER_SWAP_COMPLETE),
m_drawable(drawable),
m_glxDrawable(glxDrawable)
{
}
bool SwapEventFilter::event(xcb_generic_event_t *event)
{
xcb_glx_buffer_swap_complete_event_t *ev =
reinterpret_cast<xcb_glx_buffer_swap_complete_event_t *>(event);
// The drawable field is the X drawable when the event was synthesized
// by a WireToEvent handler, and the GLX drawable when the event was
// received over the wire
if (ev->drawable == m_drawable || ev->drawable == m_glxDrawable) {
Compositor::self()->bufferSwapComplete();
return true;
}
return false;
}
// -----------------------------------------------------------------------
GlxBackend::GlxBackend(Display *display)
: OpenGLBackend()
, m_overlayWindow(kwinApp()->platform()->createOverlayWindow())
, window(None)
, fbconfig(NULL)
, glxWindow(None)
, ctx(nullptr)
, m_bufferAge(0)
, haveSwapInterval(false)
, m_x11Display(display)
{
// Ensures calls to glXSwapBuffers will always block until the next
// retrace when using the proprietary NVIDIA driver. This must be
// set before libGL.so is loaded.
setenv("__GL_MaxFramesAllowed", "1", true);
// Force initialization of GLX integration in the Qt's xcb backend
// to make it call XESetWireToEvent callbacks, which is required
// by Mesa when using DRI2.
QOpenGLContext::supportsThreadedOpenGL();
}
static bool gs_tripleBufferUndetected = true;
static bool gs_tripleBufferNeedsDetection = false;
GlxBackend::~GlxBackend()
{
if (isFailed()) {
m_overlayWindow->destroy();
}
// TODO: cleanup in error case
// do cleanup after initBuffer()
cleanupGL();
doneCurrent();
gs_tripleBufferUndetected = true;
gs_tripleBufferNeedsDetection = false;
if (ctx)
glXDestroyContext(display(), ctx);
if (glxWindow)
glXDestroyWindow(display(), glxWindow);
if (window)
XDestroyWindow(display(), window);
qDeleteAll(m_fbconfigHash);
m_fbconfigHash.clear();
overlayWindow()->destroy();
delete m_overlayWindow;
}
typedef void (*glXFuncPtr)();
static glXFuncPtr getProcAddress(const char* name)
{
glXFuncPtr ret = nullptr;
#if HAVE_EPOXY_GLX
ret = glXGetProcAddress((const GLubyte*) name);
#endif
#if HAVE_DL_LIBRARY
if (ret == nullptr)
ret = (glXFuncPtr) dlsym(RTLD_DEFAULT, name);
#endif
return ret;
}
glXSwapIntervalMESA_func glXSwapIntervalMESA;
void GlxBackend::init()
{
// Require at least GLX 1.3
if (!checkVersion()) {
setFailed(QStringLiteral("Requires at least GLX 1.3"));
return;
}
initExtensions();
// resolve glXSwapIntervalMESA if available
if (hasExtension(QByteArrayLiteral("GLX_MESA_swap_control"))) {
glXSwapIntervalMESA = (glXSwapIntervalMESA_func) getProcAddress("glXSwapIntervalMESA");
} else {
glXSwapIntervalMESA = nullptr;
}
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);
options->setGlPreferBufferSwap(options->glPreferBufferSwap()); // resolve autosetting
if (options->glPreferBufferSwap() == Options::AutoSwapStrategy)
options->setGlPreferBufferSwap('e'); // for unknown drivers - should not happen
glPlatform->printResults();
initGL(&getProcAddress);
// Check whether certain features are supported
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");
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 (hasExtension(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 (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);
}
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_X11STANDALONE) << "Direct rendering:" << isDirectRendering();
}
bool GlxBackend::checkVersion()
{
int major, minor;
glXQueryVersion(display(), &major, &minor);
return kVersionNumber(major, minor) >= kVersionNumber(1, 3);
}
void GlxBackend::initExtensions()
{
const QByteArray string = (const char *) glXQueryExtensionsString(display(), QX11Info::appScreen());
setExtensions(string.split(' '));
}
bool GlxBackend::initRenderingContext()
{
const bool direct = true;
// Use glXCreateContextAttribsARB() when it's available
if (hasExtension(QByteArrayLiteral("GLX_ARB_create_context"))) {
const bool have_robustness = hasExtension(QByteArrayLiteral("GLX_ARB_create_context_robustness"));
const bool haveVideoMemoryPurge = hasExtension(QByteArrayLiteral("GLX_NV_robustness_video_memory_purge"));
std::vector<GlxContextAttributeBuilder> candidates;
if (options->glCoreProfile()) {
if (have_robustness) {
if (haveVideoMemoryPurge) {
GlxContextAttributeBuilder purgeMemoryCore;
purgeMemoryCore.setVersion(3, 1);
purgeMemoryCore.setRobust(true);
purgeMemoryCore.setResetOnVideoMemoryPurge(true);
candidates.emplace_back(std::move(purgeMemoryCore));
}
GlxContextAttributeBuilder robustCore;
robustCore.setVersion(3, 1);
robustCore.setRobust(true);
candidates.emplace_back(std::move(robustCore));
}
GlxContextAttributeBuilder core;
core.setVersion(3, 1);
candidates.emplace_back(std::move(core));
} else {
if (have_robustness) {
if (haveVideoMemoryPurge) {
GlxContextAttributeBuilder purgeMemoryLegacy;
purgeMemoryLegacy.setRobust(true);
purgeMemoryLegacy.setResetOnVideoMemoryPurge(true);
candidates.emplace_back(std::move(purgeMemoryLegacy));
}
GlxContextAttributeBuilder robustLegacy;
robustLegacy.setRobust(true);
candidates.emplace_back(std::move(robustLegacy));
}
GlxContextAttributeBuilder legacy;
legacy.setVersion(2, 1);
candidates.emplace_back(std::move(legacy));
}
for (auto it = candidates.begin(); it != candidates.end(); it++) {
const auto attribs = it->build();
ctx = glXCreateContextAttribsARB(display(), fbconfig, 0, true, attribs.data());
if (ctx) {
qCDebug(KWIN_X11STANDALONE) << "Created GLX context with attributes:" << &(*it);
break;
}
}
}
if (!ctx)
ctx = glXCreateNewContext(display(), fbconfig, GLX_RGBA_TYPE, NULL, direct);
if (!ctx) {
qCDebug(KWIN_X11STANDALONE) << "Failed to create an OpenGL context.";
return false;
}
if (!glXMakeCurrent(display(), glxWindow, ctx)) {
qCDebug(KWIN_X11STANDALONE) << "Failed to make the OpenGL context current.";
glXDestroyContext(display(), ctx);
ctx = 0;
return false;
}
return true;
}
bool GlxBackend::initBuffer()
{
if (!initFbConfig())
return false;
if (overlayWindow()->create()) {
xcb_connection_t * const c = connection();
// Try to create double-buffered window in the overlay
xcb_visualid_t visual;
glXGetFBConfigAttrib(display(), fbconfig, GLX_VISUAL_ID, (int *) &visual);
if (!visual) {
qCCritical(KWIN_X11STANDALONE) << "The GLXFBConfig does not have an associated X visual";
return false;
}
xcb_colormap_t colormap = xcb_generate_id(c);
xcb_create_colormap(c, false, colormap, rootWindow(), visual);
const QSize size = screens()->size();
window = xcb_generate_id(c);
xcb_create_window(c, visualDepth(visual), window, overlayWindow()->window(),
0, 0, size.width(), size.height(), 0, XCB_WINDOW_CLASS_INPUT_OUTPUT,
visual, XCB_CW_COLORMAP, &colormap);
glxWindow = glXCreateWindow(display(), fbconfig, window, NULL);
overlayWindow()->setup(window);
} else {
qCCritical(KWIN_X11STANDALONE) << "Failed to create overlay window";
return false;
}
return true;
}
bool GlxBackend::initFbConfig()
{
const int attribs[] = {
GLX_RENDER_TYPE, GLX_RGBA_BIT,
GLX_DRAWABLE_TYPE, GLX_WINDOW_BIT,
GLX_RED_SIZE, 1,
GLX_GREEN_SIZE, 1,
GLX_BLUE_SIZE, 1,
GLX_ALPHA_SIZE, 0,
GLX_DEPTH_SIZE, 0,
GLX_STENCIL_SIZE, 0,
GLX_CONFIG_CAVEAT, GLX_NONE,
GLX_DOUBLEBUFFER, true,
0
};
// Try to find a double buffered configuration
int count = 0;
GLXFBConfig *configs = glXChooseFBConfig(display(), DefaultScreen(display()), attribs, &count);
struct FBConfig {
GLXFBConfig config;
int depth;
int stencil;
};
std::deque<FBConfig> candidates;
for (int i = 0; i < count; i++) {
int depth, stencil;
glXGetFBConfigAttrib(display(), configs[i], GLX_DEPTH_SIZE, &depth);
glXGetFBConfigAttrib(display(), configs[i], GLX_STENCIL_SIZE, &stencil);
candidates.emplace_back(FBConfig{configs[i], depth, stencil});
}
if (count > 0)
XFree(configs);
std::stable_sort(candidates.begin(), candidates.end(), [](const FBConfig &left, const FBConfig &right) {
if (left.depth < right.depth)
return true;
if (left.stencil < right.stencil)
return true;
return false;
});
if (candidates.size() > 0) {
fbconfig = candidates.front().config;
int fbconfig_id, visual_id, red, green, blue, alpha, depth, stencil;
glXGetFBConfigAttrib(display(), fbconfig, GLX_FBCONFIG_ID, &fbconfig_id);
glXGetFBConfigAttrib(display(), fbconfig, GLX_VISUAL_ID, &visual_id);
glXGetFBConfigAttrib(display(), fbconfig, GLX_RED_SIZE, &red);
glXGetFBConfigAttrib(display(), fbconfig, GLX_GREEN_SIZE, &green);
glXGetFBConfigAttrib(display(), fbconfig, GLX_BLUE_SIZE, &blue);
glXGetFBConfigAttrib(display(), fbconfig, GLX_ALPHA_SIZE, &alpha);
glXGetFBConfigAttrib(display(), fbconfig, GLX_DEPTH_SIZE, &depth);
glXGetFBConfigAttrib(display(), fbconfig, GLX_STENCIL_SIZE, &stencil);
qCDebug(KWIN_X11STANDALONE, "Choosing GLXFBConfig %#x X visual %#x depth %d RGBA %d:%d:%d:%d ZS %d:%d",
fbconfig_id, visual_id, visualDepth(visual_id), red, green, blue, alpha, depth, stencil);
}
if (fbconfig == nullptr) {
qCCritical(KWIN_X11STANDALONE) << "Failed to find a usable framebuffer configuration";
return false;
}
return true;
}
void GlxBackend::initVisualDepthHashTable()
{
const xcb_setup_t *setup = xcb_get_setup(connection());
for (auto screen = xcb_setup_roots_iterator(setup); screen.rem; xcb_screen_next(&screen)) {
for (auto depth = xcb_screen_allowed_depths_iterator(screen.data); depth.rem; xcb_depth_next(&depth)) {
const int len = xcb_depth_visuals_length(depth.data);
const xcb_visualtype_t *visuals = xcb_depth_visuals(depth.data);
for (int i = 0; i < len; i++)
m_visualDepthHash.insert(visuals[i].visual_id, depth.data->depth);
}
}
}
int GlxBackend::visualDepth(xcb_visualid_t visual) const
{
return m_visualDepthHash.value(visual);
}
static inline int bitCount(uint32_t mask)
{
#if defined(__GNUC__)
return __builtin_popcount(mask);
#else
int count = 0;
while (mask) {
count += (mask & 1);
mask >>= 1;
}
return count;
#endif
}
FBConfigInfo *GlxBackend::infoForVisual(xcb_visualid_t visual)
{
auto it = m_fbconfigHash.constFind(visual);
if (it != m_fbconfigHash.constEnd()) {
return it.value();
}
FBConfigInfo *info = new FBConfigInfo;
m_fbconfigHash.insert(visual, info);
info->fbconfig = nullptr;
info->bind_texture_format = 0;
info->texture_targets = 0;
info->y_inverted = 0;
info->mipmap = 0;
const xcb_render_pictformat_t format = XRenderUtils::findPictFormat(visual);
const xcb_render_directformat_t *direct = XRenderUtils::findPictFormatInfo(format);
if (!direct) {
qCCritical(KWIN_X11STANDALONE).nospace() << "Could not find a picture format for visual 0x" << hex << visual;
return info;
}
const int red_bits = bitCount(direct->red_mask);
const int green_bits = bitCount(direct->green_mask);
const int blue_bits = bitCount(direct->blue_mask);
const int alpha_bits = bitCount(direct->alpha_mask);
const int depth = visualDepth(visual);
const auto rgb_sizes = std::tie(red_bits, green_bits, blue_bits);
const int attribs[] = {
GLX_RENDER_TYPE, GLX_RGBA_BIT,
GLX_DRAWABLE_TYPE, GLX_WINDOW_BIT | GLX_PIXMAP_BIT,
GLX_X_VISUAL_TYPE, GLX_TRUE_COLOR,
GLX_X_RENDERABLE, True,
GLX_CONFIG_CAVEAT, int(GLX_DONT_CARE), // The ARGB32 visual is marked non-conformant in Catalyst
GLX_FRAMEBUFFER_SRGB_CAPABLE_EXT, int(GLX_DONT_CARE), // The ARGB32 visual is marked sRGB capable in mesa/i965
GLX_BUFFER_SIZE, red_bits + green_bits + blue_bits + alpha_bits,
GLX_RED_SIZE, red_bits,
GLX_GREEN_SIZE, green_bits,
GLX_BLUE_SIZE, blue_bits,
GLX_ALPHA_SIZE, alpha_bits,
GLX_STENCIL_SIZE, 0,
GLX_DEPTH_SIZE, 0,
0
};
int count = 0;
GLXFBConfig *configs = glXChooseFBConfig(display(), DefaultScreen(display()), attribs, &count);
if (count < 1) {
qCCritical(KWIN_X11STANDALONE).nospace() << "Could not find a framebuffer configuration for visual 0x" << hex << visual;
return info;
}
struct FBConfig {
GLXFBConfig config;
int depth;
int stencil;
int format;
};
std::deque<FBConfig> candidates;
for (int i = 0; i < count; i++) {
int red, green, blue;
glXGetFBConfigAttrib(display(), configs[i], GLX_RED_SIZE, &red);
glXGetFBConfigAttrib(display(), configs[i], GLX_GREEN_SIZE, &green);
glXGetFBConfigAttrib(display(), configs[i], GLX_BLUE_SIZE, &blue);
if (std::tie(red, green, blue) != rgb_sizes)
continue;
xcb_visualid_t visual;
glXGetFBConfigAttrib(display(), configs[i], GLX_VISUAL_ID, (int *) &visual);
if (visualDepth(visual) != depth)
continue;
int bind_rgb, bind_rgba;
glXGetFBConfigAttrib(display(), configs[i], GLX_BIND_TO_TEXTURE_RGBA_EXT, &bind_rgba);
glXGetFBConfigAttrib(display(), configs[i], GLX_BIND_TO_TEXTURE_RGB_EXT, &bind_rgb);
if (!bind_rgb && !bind_rgba)
continue;
int depth, stencil;
glXGetFBConfigAttrib(display(), configs[i], GLX_DEPTH_SIZE, &depth);
glXGetFBConfigAttrib(display(), configs[i], GLX_STENCIL_SIZE, &stencil);
int texture_format;
if (alpha_bits)
texture_format = bind_rgba ? GLX_TEXTURE_FORMAT_RGBA_EXT : GLX_TEXTURE_FORMAT_RGB_EXT;
else
texture_format = bind_rgb ? GLX_TEXTURE_FORMAT_RGB_EXT : GLX_TEXTURE_FORMAT_RGBA_EXT;
candidates.emplace_back(FBConfig{configs[i], depth, stencil, texture_format});
}
if (count > 0)
XFree(configs);
std::stable_sort(candidates.begin(), candidates.end(), [](const FBConfig &left, const FBConfig &right) {
if (left.depth < right.depth)
return true;
if (left.stencil < right.stencil)
return true;
return false;
});
if (candidates.size() > 0) {
const FBConfig &candidate = candidates.front();
int y_inverted, texture_targets;
glXGetFBConfigAttrib(display(), candidate.config, GLX_BIND_TO_TEXTURE_TARGETS_EXT, &texture_targets);
glXGetFBConfigAttrib(display(), candidate.config, GLX_Y_INVERTED_EXT, &y_inverted);
info->fbconfig = candidate.config;
info->bind_texture_format = candidate.format;
info->texture_targets = texture_targets;
info->y_inverted = y_inverted;
info->mipmap = 0;
}
if (info->fbconfig) {
int fbc_id = 0;
int visual_id = 0;
glXGetFBConfigAttrib(display(), info->fbconfig, GLX_FBCONFIG_ID, &fbc_id);
glXGetFBConfigAttrib(display(), info->fbconfig, GLX_VISUAL_ID, &visual_id);
qCDebug(KWIN_X11STANDALONE).nospace() << "Using FBConfig 0x" << hex << fbc_id << " for visual 0x" << hex << visual_id;
}
return info;
}
void GlxBackend::setSwapInterval(int interval)
{
if (m_haveEXTSwapControl)
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()
{
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;
setBlocksForRetrace(result == 'd');
}
}
} 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)
glDrawBuffer(GL_FRONT);
copyPixels(lastDamage());
glDrawBuffer(GL_BACK);
}
setLastDamage(QRegion());
if (!supportsBufferAge()) {
glXWaitGL();
XFlush(display());
}
}
void GlxBackend::screenGeometryChanged(const QSize &size)
{
doneCurrent();
XMoveResizeWindow(display(), window, 0, 0, size.width(), size.height());
overlayWindow()->setup(window);
Xcb::sync();
makeCurrent();
glViewport(0, 0, size.width(), size.height());
// The back buffer contents are now undefined
m_bufferAge = 0;
}
SceneOpenGLTexturePrivate *GlxBackend::createBackendTexture(SceneOpenGLTexture *texture)
{
return new GlxTexture(texture, this);
}
QRegion GlxBackend::prepareRenderingFrame()
{
QRegion repaint;
if (gs_tripleBufferNeedsDetection) {
// the composite timer floors the repaint frequency. This can pollute our triple buffering
// detection because the glXSwapBuffers call for the new frame has to wait until the pending
// one scanned out.
// So we compensate for that by waiting an extra milisecond to give the driver the chance to
// fllush the buffer queue
usleep(1000);
}
present();
if (supportsBufferAge())
repaint = accumulatedDamageHistory(m_bufferAge);
startRenderTimer();
glXWaitX();
return repaint;
}
void GlxBackend::endRenderingFrame(const QRegion &renderedRegion, const QRegion &damagedRegion)
{
if (damagedRegion.isEmpty()) {
setLastDamage(QRegion());
// If the damaged region of a window is fully occluded, the only
// rendering done, if any, will have been to repair a reused back
// buffer, making it identical to the front buffer.
//
// In this case we won't post the back buffer. Instead we'll just
// set the buffer age to 1, so the repaired regions won't be
// rendered again in the next frame.
if (!renderedRegion.isEmpty())
glFlush();
m_bufferAge = 1;
return;
}
setLastDamage(renderedRegion);
if (!blocksForRetrace()) {
// This also sets lastDamage to empty which prevents the frame from
// being posted again when prepareRenderingFrame() is called.
present();
} else {
// Make sure that the GPU begins processing the command stream
// now and not the next time prepareRenderingFrame() is called.
glFlush();
}
if (overlayWindow()->window()) // show the window only after the first pass,
overlayWindow()->show(); // since that pass may take long
// Save the damaged region to history
if (supportsBufferAge())
addToDamageHistory(damagedRegion);
}
bool GlxBackend::makeCurrent()
{
if (QOpenGLContext *context = QOpenGLContext::currentContext()) {
// Workaround to tell Qt that no QOpenGLContext is current
context->doneCurrent();
}
const bool current = glXMakeCurrent(display(), glxWindow, ctx);
return current;
}
void GlxBackend::doneCurrent()
{
glXMakeCurrent(display(), None, nullptr);
}
OverlayWindow* GlxBackend::overlayWindow()
{
return m_overlayWindow;
}
bool GlxBackend::usesOverlayWindow() const
{
return true;
}
/********************************************************
* GlxTexture
*******************************************************/
GlxTexture::GlxTexture(SceneOpenGLTexture *texture, GlxBackend *backend)
: SceneOpenGLTexturePrivate()
, q(texture)
, m_backend(backend)
, m_glxpixmap(None)
{
}
GlxTexture::~GlxTexture()
{
if (m_glxpixmap != None) {
if (!options->isGlStrictBinding()) {
glXReleaseTexImageEXT(display(), m_glxpixmap, GLX_FRONT_LEFT_EXT);
}
glXDestroyPixmap(display(), m_glxpixmap);
m_glxpixmap = None;
}
}
void GlxTexture::onDamage()
{
if (options->isGlStrictBinding() && m_glxpixmap) {
glXReleaseTexImageEXT(display(), m_glxpixmap, GLX_FRONT_LEFT_EXT);
glXBindTexImageEXT(display(), m_glxpixmap, GLX_FRONT_LEFT_EXT, NULL);
}
GLTexturePrivate::onDamage();
}
bool GlxTexture::loadTexture(xcb_pixmap_t pixmap, const QSize &size, xcb_visualid_t visual)
{
if (pixmap == XCB_NONE || size.isEmpty() || visual == XCB_NONE)
return false;
const FBConfigInfo *info = m_backend->infoForVisual(visual);
if (!info || info->fbconfig == nullptr)
return false;
if (info->texture_targets & GLX_TEXTURE_2D_BIT_EXT) {
m_target = GL_TEXTURE_2D;
m_scale.setWidth(1.0f / m_size.width());
m_scale.setHeight(1.0f / m_size.height());
} else {
assert(info->texture_targets & GLX_TEXTURE_RECTANGLE_BIT_EXT);
m_target = GL_TEXTURE_RECTANGLE;
m_scale.setWidth(1.0f);
m_scale.setHeight(1.0f);
}
const int attrs[] = {
GLX_TEXTURE_FORMAT_EXT, info->bind_texture_format,
GLX_MIPMAP_TEXTURE_EXT, false,
GLX_TEXTURE_TARGET_EXT, m_target == GL_TEXTURE_2D ? GLX_TEXTURE_2D_EXT : GLX_TEXTURE_RECTANGLE_EXT,
0
};
m_glxpixmap = glXCreatePixmap(display(), info->fbconfig, pixmap, attrs);
m_size = size;
m_yInverted = info->y_inverted ? true : false;
m_canUseMipmaps = false;
glGenTextures(1, &m_texture);
q->setDirty();
q->setFilter(GL_NEAREST);
glBindTexture(m_target, m_texture);
glXBindTexImageEXT(display(), m_glxpixmap, GLX_FRONT_LEFT_EXT, nullptr);
updateMatrix();
return true;
}
bool GlxTexture::loadTexture(WindowPixmap *pixmap)
{
Toplevel *t = pixmap->toplevel();
return loadTexture(pixmap->pixmap(), t->size(), t->visual());
}
OpenGLBackend *GlxTexture::backend()
{
return m_backend;
}
} // namespace