Make an EGL context current when initializing GL extensions

Reviewed-by: trustme

3 files changed, 37 insertions, 0 deletions

diff --git a/src/opengl/qgl_qws.cpp b/src/opengl/qgl_qws.cpp
index c71ceeb..759f9de 100644
--- a/src/opengl/qgl_qws.cpp
+++ b/src/opengl/qgl_qws.cpp
@@ -41,6 +41,7 @@
 
 #include "qgl.h"
 #include "qgl_egl_p.h"
+#include "qglpixelbuffer.h"
 
 #include <qglscreen_qws.h>
 #include <qscreenproxy_qws.h>
@@ -411,7 +412,29 @@ void QGLExtensions::init()
     if (init_done)
         return;
     init_done = true;
+
+    // We need a context current to initialize the extensions,
+    // but getting a valid EGLNativeWindowType this early can be
+    // problematic under QWS.  So use a pbuffer instead.
+    //
+    // Unfortunately OpenGL/ES 2.0 systems don't normally
+    // support pbuffers, so we have no choice but to try
+    // our luck with a window on those systems.
+#if defined(QT_OPENGL_ES_2)
+    QGLWidget tmpWidget;
+    tmpWidget.makeCurrent();
+
     init_extensions();
+
+    tmpWidget.doneCurrent();
+#else
+    QGLPixelBuffer pbuffer(16, 16);
+    pbuffer.makeCurrent();
+
+    init_extensions();
+
+    pbuffer.doneCurrent();
+#endif
 }
 
 QT_END_NAMESPACE
diff --git a/src/opengl/qgl_wince.cpp b/src/opengl/qgl_wince.cpp
index 881d7f7..83efca8 100644
--- a/src/opengl/qgl_wince.cpp
+++ b/src/opengl/qgl_wince.cpp
@@ -730,7 +730,14 @@ void QGLExtensions::init()
     if (init_done)
         return;
     init_done = true;
+
+    // We need a context current to initialize the extensions.
+    QGLWidget tmpWidget;
+    tmpWidget.makeCurrent();
+
     init_extensions();
+
+    tmpWidget.doneCurrent();
 }
 
 QT_END_NAMESPACE
diff --git a/src/opengl/qgl_x11egl.cpp b/src/opengl/qgl_x11egl.cpp
index 055138d..c54315f 100644
--- a/src/opengl/qgl_x11egl.cpp
+++ b/src/opengl/qgl_x11egl.cpp
@@ -470,7 +470,14 @@ void QGLExtensions::init()
     if (init_done)
         return;
     init_done = true;
+
+    // We need a context current to initialize the extensions.
+    QGLWidget tmpWidget;
+    tmpWidget.makeCurrent();
+
     init_extensions();
+
+    tmpWidget.doneCurrent();
 }
 
 // Re-creates the EGL surface if the window ID has changed or if force is true