File indexing completed on 2025-04-27 11:32:59

 /*
     SPDX-FileCopyrightText: 2010, 2012 Martin Gräßlin <mgraesslin@kde.org>
     SPDX-FileCopyrightText: 2020 Vlad Zahorodnii <vlad.zahorodnii@kde.org>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 #include "x11_standalone_egl_backend.h"
 #include "core/outputbackend.h"
 #include "core/overlaywindow.h"
 #include "core/renderloop_p.h"
 #include "kwinglplatform.h"
 #include "options.h"
 #include "scene/surfaceitem_x11.h"
 #include "scene/workspacescene.h"
 #include "softwarevsyncmonitor.h"
 #include "workspace.h"
 #include "x11_standalone_backend.h"
 #include "x11_standalone_logging.h"
 #include "x11_standalone_overlaywindow.h"
 
 #include <QOpenGLContext>
 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
 #include <QtPlatformHeaders/QEGLNativeContext>
 #endif
 
 namespace KWin
 {
 
 EglLayer::EglLayer(EglBackend *backend)
     : m_backend(backend)
 {
 }
 
 std::optional<OutputLayerBeginFrameInfo> EglLayer::beginFrame()
 {
     return m_backend->beginFrame();
 }
 
 bool EglLayer::endFrame(const QRegion &renderedRegion, const QRegion &damagedRegion)
 {
     m_backend->endFrame(renderedRegion, damagedRegion);
     return true;
 }
 
 EglBackend::EglBackend(Display *display, X11StandaloneBackend *backend)
     : EglOnXBackend(kwinApp()->x11Connection(), display, kwinApp()->x11RootWindow())
     , m_backend(backend)
     , m_overlayWindow(std::make_unique<OverlayWindowX11>())
     , m_layer(std::make_unique<EglLayer>(this))
 {
     // There is no any way to determine when a buffer swap completes with EGL. Fallback
     // to software vblank events. Could we use the Present extension to get notified when
     // the overlay window is actually presented on the screen?
     m_vsyncMonitor = SoftwareVsyncMonitor::create();
     connect(backend->renderLoop(), &RenderLoop::refreshRateChanged, this, [this, backend]() {
         m_vsyncMonitor->setRefreshRate(backend->renderLoop()->refreshRate());
     });
     m_vsyncMonitor->setRefreshRate(backend->renderLoop()->refreshRate());
 
     connect(m_vsyncMonitor.get(), &VsyncMonitor::vblankOccurred, this, &EglBackend::vblank);
     connect(workspace(), &Workspace::geometryChanged, this, &EglBackend::screenGeometryChanged);
 }
 
 EglBackend::~EglBackend()
 {
     // No completion events will be received for in-flight frames, this may lock the
     // render loop. We need to ensure that the render loop is back to its initial state
     // if the render backend is about to be destroyed.
     RenderLoopPrivate::get(m_backend->renderLoop())->invalidate();
 
     if (isFailed() && m_overlayWindow) {
         m_overlayWindow->destroy();
     }
     cleanup();
 
     if (m_overlayWindow && m_overlayWindow->window()) {
         m_overlayWindow->destroy();
     }
 }
 
 std::unique_ptr<SurfaceTexture> EglBackend::createSurfaceTextureX11(SurfacePixmapX11 *texture)
 {
     return std::make_unique<EglSurfaceTextureX11>(this, texture);
 }
 
 void EglBackend::init()
 {
     QOpenGLContext *qtShareContext = QOpenGLContext::globalShareContext();
     EGLDisplay shareDisplay = EGL_NO_DISPLAY;
     EGLContext shareContext = EGL_NO_CONTEXT;
     if (qtShareContext) {
         qDebug(KWIN_X11STANDALONE) << "Global share context format:" << qtShareContext->format();
 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
         const QVariant nativeHandle = qtShareContext->nativeHandle();
         if (!nativeHandle.canConvert<QEGLNativeContext>()) {
             setFailed(QStringLiteral("Invalid QOpenGLContext::globalShareContext()"));
             return;
         } else {
             QEGLNativeContext handle = qvariant_cast<QEGLNativeContext>(nativeHandle);
             shareContext = handle.context();
             shareDisplay = handle.display();
         }
 #else
         const auto nativeHandle = qtShareContext->nativeInterface<QNativeInterface::QEGLContext>();
         if (nativeHandle) {
             shareContext = nativeHandle->nativeContext();
             shareDisplay = nativeHandle->display();
         } else {
             setFailed(QStringLiteral("Invalid QOpenGLContext::globalShareContext()"));
             return;
         }
 #endif
     }
     if (shareContext == EGL_NO_CONTEXT) {
         setFailed(QStringLiteral("QOpenGLContext::globalShareContext() is required"));
         return;
     }
 
     m_fbo = std::make_unique<GLFramebuffer>(0, workspace()->geometry().size());
 
     kwinApp()->outputBackend()->setSceneEglDisplay(shareDisplay);
     kwinApp()->outputBackend()->setSceneEglGlobalShareContext(shareContext);
     EglOnXBackend::init();
 }
 
 bool EglBackend::createSurfaces()
 {
     if (!m_overlayWindow) {
         return false;
     }
 
     if (!m_overlayWindow->create()) {
         qCCritical(KWIN_X11STANDALONE) << "Could not get overlay window";
         return false;
     } else {
         m_overlayWindow->setup(XCB_WINDOW_NONE);
     }
 
     EGLSurface surface = createSurface(m_overlayWindow->window());
     if (surface == EGL_NO_SURFACE) {
         return false;
     }
     setSurface(surface);
     return true;
 }
 
 void EglBackend::screenGeometryChanged()
 {
     overlayWindow()->resize(workspace()->geometry().size());
 
     // The back buffer contents are now undefined
     m_bufferAge = 0;
     m_fbo = std::make_unique<GLFramebuffer>(0, workspace()->geometry().size());
 }
 
 OutputLayerBeginFrameInfo EglBackend::beginFrame()
 {
     makeCurrent();
 
     QRegion repaint;
     if (supportsBufferAge()) {
         repaint = m_damageJournal.accumulate(m_bufferAge, infiniteRegion());
     }
 
     eglWaitNative(EGL_CORE_NATIVE_ENGINE);
 
     return OutputLayerBeginFrameInfo{
         .renderTarget = RenderTarget(m_fbo.get()),
         .repaint = repaint,
     };
 }
 
 void EglBackend::endFrame(const QRegion &renderedRegion, const QRegion &damagedRegion)
 {
     // Save the damaged region to history
     if (supportsBufferAge()) {
         m_damageJournal.add(damagedRegion);
     }
     m_lastRenderedRegion = renderedRegion;
 }
 
 void EglBackend::present(Output *output)
 {
     // Start the software vsync monitor. There is no any reliable way to determine when
     // eglSwapBuffers() or eglSwapBuffersWithDamageEXT() completes.
     m_vsyncMonitor->arm();
 
     QRegion effectiveRenderedRegion = m_lastRenderedRegion;
     if (!GLPlatform::instance()->isGLES()) {
         const QRect displayRect = workspace()->geometry();
         if (!supportsBufferAge() && options->glPreferBufferSwap() == Options::CopyFrontBuffer && m_lastRenderedRegion != displayRect) {
             glReadBuffer(GL_FRONT);
             copyPixels(QRegion(displayRect) - m_lastRenderedRegion, displayRect.size());
             glReadBuffer(GL_BACK);
             effectiveRenderedRegion = displayRect;
         }
     }
 
     presentSurface(surface(), effectiveRenderedRegion, workspace()->geometry());
 
     if (overlayWindow() && overlayWindow()->window()) { // show the window only after the first pass,
         overlayWindow()->show(); // since that pass may take long
     }
 }
 
 void EglBackend::presentSurface(EGLSurface surface, const QRegion &damage, const QRect &screenGeometry)
 {
     const bool fullRepaint = supportsBufferAge() || (damage == screenGeometry);
 
     if (fullRepaint || !havePostSubBuffer()) {
         // the entire screen changed, or we cannot do partial updates (which implies we enabled surface preservation)
         eglSwapBuffers(eglDisplay(), surface);
         if (supportsBufferAge()) {
             eglQuerySurface(eglDisplay(), surface, EGL_BUFFER_AGE_EXT, &m_bufferAge);
         }
     } else {
         // a part of the screen changed, and we can use eglPostSubBufferNV to copy the updated area
         for (const QRect &r : damage) {
             eglPostSubBufferNV(eglDisplay(), surface, r.left(), screenGeometry.height() - r.bottom() - 1, r.width(), r.height());
         }
     }
 }
 
 OverlayWindow *EglBackend::overlayWindow() const
 {
     return m_overlayWindow.get();
 }
 
 OutputLayer *EglBackend::primaryLayer(Output *output)
 {
     return m_layer.get();
 }
 
 void EglBackend::vblank(std::chrono::nanoseconds timestamp)
 {
     RenderLoopPrivate *renderLoopPrivate = RenderLoopPrivate::get(m_backend->renderLoop());
     renderLoopPrivate->notifyFrameCompleted(timestamp);
 }
 
 EglSurfaceTextureX11::EglSurfaceTextureX11(EglBackend *backend, SurfacePixmapX11 *texture)
     : OpenGLSurfaceTextureX11(backend, texture)
 {
 }
 
 bool EglSurfaceTextureX11::create()
 {
     auto texture = std::make_unique<EglPixmapTexture>(static_cast<EglBackend *>(m_backend));
     if (texture->create(m_pixmap)) {
         m_texture = std::move(texture);
         return true;
     } else {
         return false;
     }
 }
 
 void EglSurfaceTextureX11::update(const QRegion &region)
 {
     // mipmaps need to be updated
     m_texture->setDirty();
 }
 
 EglPixmapTexture::EglPixmapTexture(EglBackend *backend)
     : GLTexture(*new EglPixmapTexturePrivate(this, backend))
 {
 }
 
 bool EglPixmapTexture::create(SurfacePixmapX11 *texture)
 {
     Q_D(EglPixmapTexture);
     return d->create(texture);
 }
 
 EglPixmapTexturePrivate::EglPixmapTexturePrivate(EglPixmapTexture *texture, EglBackend *backend)
     : q(texture)
     , m_backend(backend)
 {
     m_target = GL_TEXTURE_2D;
 }
 
 EglPixmapTexturePrivate::~EglPixmapTexturePrivate()
 {
     if (m_image != EGL_NO_IMAGE_KHR) {
         eglDestroyImageKHR(m_backend->eglDisplay(), m_image);
     }
 }
 
 bool EglPixmapTexturePrivate::create(SurfacePixmapX11 *pixmap)
 {
     const xcb_pixmap_t nativePixmap = pixmap->pixmap();
     if (nativePixmap == XCB_NONE) {
         return false;
     }
 
     glGenTextures(1, &m_texture);
     q->setWrapMode(GL_CLAMP_TO_EDGE);
     q->setFilter(GL_LINEAR);
     q->bind();
     const EGLint attribs[] = {
         EGL_IMAGE_PRESERVED_KHR, EGL_TRUE,
         EGL_NONE};
     m_image = eglCreateImageKHR(m_backend->eglDisplay(),
                                 EGL_NO_CONTEXT,
                                 EGL_NATIVE_PIXMAP_KHR,
                                 reinterpret_cast<EGLClientBuffer>(static_cast<uintptr_t>(nativePixmap)),
                                 attribs);
 
     if (EGL_NO_IMAGE_KHR == m_image) {
         qCDebug(KWIN_X11STANDALONE) << "failed to create egl image";
         q->unbind();
         return false;
     }
     glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, static_cast<GLeglImageOES>(m_image));
     q->unbind();
     q->setYInverted(true);
     m_size = pixmap->size();
     updateMatrix();
     return true;
 }
 
 void EglPixmapTexturePrivate::onDamage()
 {
     if (options->isGlStrictBinding()) {
         // This is just implemented to be consistent with
         // the example in mesa/demos/src/egl/opengles1/texture_from_pixmap.c
         eglWaitNative(EGL_CORE_NATIVE_ENGINE);
         glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, static_cast<GLeglImageOES>(m_image));
     }
     GLTexturePrivate::onDamage();
 }
 
 } // namespace KWin