Add QEGLContext::invalidateContext

QEGLContext::invalidateContext will mark that egl context is invalide
and trigger SceneGraph to destroy it, create a new one and re-create
and re-upload all resources (e.g. textures) associated with the current
state of the SceneGraph

In addition this change also improves
QEglFSWindow::invalidateSurface() and
QEglFSContext::eglSurfaceForPlatformSurface(..)

Where QEglFSWindow::invalidateSurface() will now destroy the
corresponding EGLSurface via eglDestroySurface, including "unbinding"
it from the current thread via eglMakeCurrent and
un-setting the screen's EGLSurface in case it's the same resource.

QEglFSContext::eglSurfaceForPlatformSurface(..) will now call
QEglFSWindow::resetSurface() in case of getting a EGL_NO_SURFACE
from the QEglFSWindow (which happens if above invalidateSurface()
was called before) - therefor re-creating the resource if
it was destoyed via QEglFSWindow::invalidateSurface()

Pick-to: 6.5
Change-Id: I37badd1fc11e993c395fb1502e9bd27ebe18b821
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

2 files changed, 36 insertions, 4 deletions

diff --git a/src/plugins/platforms/eglfs/api/qeglfscontext.cpp b/src/plugins/platforms/eglfs/api/qeglfscontext.cpp
index a17b567b24..9c10c1a998 100644
--- a/src/plugins/platforms/eglfs/api/qeglfscontext.cpp
+++ b/src/plugins/platforms/eglfs/api/qeglfscontext.cpp
@@ -22,10 +22,19 @@ QEglFSContext::QEglFSContext(const QSurfaceFormat &format, QPlatformOpenGLContex
 
 EGLSurface QEglFSContext::eglSurfaceForPlatformSurface(QPlatformSurface *surface)
 {
-    if (surface->surface()->surfaceClass() == QSurface::Window)
-        return static_cast<QEglFSWindow *>(surface)->surface();
-    else
+    if (surface->surface()->surfaceClass() == QSurface::Window) {
+
+        QEglFSWindow *w = static_cast<QEglFSWindow *>(surface);
+        EGLSurface s = w->surface();
+        if (s == EGL_NO_SURFACE) {
+            w->resetSurface();
+            s = w->surface();
+        }
+        return s;
+
+    } else {
         return static_cast<QEGLPbuffer *>(surface)->pbuffer();
+    }
 }
 
 EGLSurface QEglFSContext::createTemporaryOffscreenSurface()
diff --git a/src/plugins/platforms/eglfs/api/qeglfswindow.cpp b/src/plugins/platforms/eglfs/api/qeglfswindow.cpp
index bbd0b8ed68..1a31f97d7b 100644
--- a/src/plugins/platforms/eglfs/api/qeglfswindow.cpp
+++ b/src/plugins/platforms/eglfs/api/qeglfswindow.cpp
@@ -22,6 +22,8 @@
 
 QT_BEGIN_NAMESPACE
 
+Q_DECLARE_LOGGING_CATEGORY(qLcEglDevDebug)
+
 QEglFSWindow::QEglFSWindow(QWindow *w)
     : QPlatformWindow(w),
 #ifndef QT_NO_OPENGL
@@ -162,8 +164,29 @@ void QEglFSWindow::destroy()
 void QEglFSWindow::invalidateSurface()
 {
     if (m_surface != EGL_NO_SURFACE) {
-        eglDestroySurface(screen()->display(), m_surface);
+        qCDebug(qLcEglDevDebug) << Q_FUNC_INFO << " about to destroy EGLSurface: " << m_surface;
+
+        bool ok = eglDestroySurface(screen()->display(), m_surface);
+
+        if (!ok) {
+            qCWarning(qLcEglDevDebug, "QEglFSWindow::invalidateSurface() eglDestroySurface failed!"
+                                      " Follow-up errors or memory leaks are possible."
+                                      " eglGetError(): %x", eglGetError());
+        }
+
+        if (eglGetCurrentSurface(EGL_READ) == m_surface ||
+                eglGetCurrentSurface(EGL_DRAW) == m_surface) {
+            bool ok = eglMakeCurrent(eglGetCurrentDisplay(), EGL_NO_DISPLAY, EGL_NO_DISPLAY, EGL_NO_CONTEXT);
+            qCDebug(qLcEglDevDebug) << Q_FUNC_INFO << " due to eglDestroySurface on *currently* bound surface"
+                                    << "we just called eglMakeCurrent(..,0,0,0)! It returned: " << ok;
+        }
+
+        if (screen()->primarySurface() == m_surface)
+            screen()->setPrimarySurface(EGL_NO_SURFACE);
+
+
         m_surface = EGL_NO_SURFACE;
+        m_flags = m_flags & ~Created;
     }
     qt_egl_device_integration()->destroyNativeWindow(m_window);
     m_window = 0;