Better handling of GLX / EGL errors.

If context creation fails, try again without a shared context. Added
QPlatformOpenGLContext::isSharing() and
QPlatformOpenGLContext::isValid() to propagate whether the platform
context was successfully created with or without sharing.

Change-Id: I37080b645f531fd207946441057be6d3f6be3f6e
Reviewed-by: Jørgen Lind <jorgen.lind@nokia.com>

2 files changed, 8 insertions, 6 deletions

diff --git a/src/platformsupport/eglconvenience/qeglplatformcontext.cpp b/src/platformsupport/eglconvenience/qeglplatformcontext.cpp
index dfa0bacd35..1f1f215494 100644
--- a/src/platformsupport/eglconvenience/qeglplatformcontext.cpp
+++ b/src/platformsupport/eglconvenience/qeglplatformcontext.cpp
@@ -56,7 +56,7 @@ QEGLPlatformContext::QEGLPlatformContext(const QSurfaceFormat &format, QPlatform
     EGLConfig config = q_configFromGLFormat(display, format, true);
     m_format = q_glFormatFromConfig(display, config);
 
-    EGLContext shareContext = share ? static_cast<QEGLPlatformContext *>(share)->m_eglContext : 0;
+    m_shareContext = share ? static_cast<QEGLPlatformContext *>(share)->m_eglContext : 0;
 
     QVector<EGLint> contextAttrs;
     contextAttrs.append(EGL_CONTEXT_CLIENT_VERSION);
@@ -64,11 +64,10 @@ QEGLPlatformContext::QEGLPlatformContext(const QSurfaceFormat &format, QPlatform
     contextAttrs.append(EGL_NONE);
 
     eglBindAPI(m_eglApi);
-    m_eglContext = eglCreateContext(m_eglDisplay, config, shareContext, contextAttrs.constData());
-    if (m_eglContext == EGL_NO_CONTEXT) {
-        qWarning("Could not create the egl context\n");
-        eglTerminate(m_eglDisplay);
-        qFatal("EGL error");
+    m_eglContext = eglCreateContext(m_eglDisplay, config, m_shareContext, contextAttrs.constData());
+    if (m_eglContext == EGL_NO_CONTEXT && m_shareContext != EGL_NO_CONTEXT) {
+        m_shareContext = 0;
+        m_eglContext = eglCreateContext(m_eglDisplay, config, 0, contextAttrs.constData());
     }
 }
 
diff --git a/src/platformsupport/eglconvenience/qeglplatformcontext_p.h b/src/platformsupport/eglconvenience/qeglplatformcontext_p.h
index c38af1dfda..7002c8b9c2 100644
--- a/src/platformsupport/eglconvenience/qeglplatformcontext_p.h
+++ b/src/platformsupport/eglconvenience/qeglplatformcontext_p.h
@@ -59,6 +59,8 @@ public:
     void (*getProcAddress(const QByteArray &procName)) ();
 
     QSurfaceFormat format() const;
+    bool isSharing() const { return m_shareContext != EGL_NO_CONTEXT; }
+    bool isValid() const { return m_eglContext != EGL_NO_CONTEXT; }
 
     EGLContext eglContext() const;
 
@@ -67,6 +69,7 @@ protected:
 
 private:
     EGLContext m_eglContext;
+    EGLContext m_shareContext;
     EGLDisplay m_eglDisplay;
     EGLenum m_eglApi;