From 2bc038adc905497891294019007fcf0bf85f5638 Mon Sep 17 00:00:00 2001 From: Laszlo Agocs Date: Mon, 12 Jan 2015 16:52:05 +0100 Subject: Expose context loss On platforms like Windows (and presumably on mobile devices too) the loss of the context (e.g. the underlying D3D device in case of ANGLE) is an event that can happen randomly and needs sufficient handling. Enhance QOpenGLContext::isValid() with the purpose of indicating context loss. Currently only the Windows EGL backend (ANGLE) has support for it. Other platforms may be added later. Task-number: QTBUG-43263 Change-Id: I8177694c1ee7cebbd5d330e34757fd94c563e6d6 Reviewed-by: Friedemann Kleint --- src/gui/kernel/qopenglcontext.cpp | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'src/gui/kernel/qopenglcontext.cpp') diff --git a/src/gui/kernel/qopenglcontext.cpp b/src/gui/kernel/qopenglcontext.cpp index 3fccd6ba9a..90e9235353 100644 --- a/src/gui/kernel/qopenglcontext.cpp +++ b/src/gui/kernel/qopenglcontext.cpp @@ -590,10 +590,10 @@ QVariant QOpenGLContext::nativeHandle() const */ bool QOpenGLContext::create() { - if (isValid()) + Q_D(QOpenGLContext); + if (d->platformGLContext) destroy(); - Q_D(QOpenGLContext); d->platformGLContext = QGuiApplicationPrivate::platformIntegration()->createPlatformOpenGLContext(this); if (!d->platformGLContext) return false; @@ -676,6 +676,15 @@ QOpenGLContext::~QOpenGLContext() /*! Returns if this context is valid, i.e. has been successfully created. + On some platforms the return value of \c false for a context that was + successfully created previously indicates that the OpenGL context was lost. + + The typical way to handle context loss scenarios in applications is to + check via this function whenever makeCurrent() fails and returns \c false. + If this function then returns \c false, recreate the underlying native + OpenGL context by calling create(), call makeCurrent() again and then + reinitialize all OpenGL resources. + \sa create() */ bool QOpenGLContext::isValid() const -- cgit v1.2.3