Lighthouse: Fix QGLContext::currentContext for systems with limited

resources. The example plugins EGLFS uses only 1 native
context. Make sure that we only use this 1 context, and that we dont
wrap it in many different QPlatformGLContexts or QGLContexts instanses.

This change also removes the QPlatformWindow link which was made in the
initial QPlatformGLContext change. Lighthouse has to support situations
where a context isnt bound to a QPlatformWindow.

Reviewed-by: gunnar

1 files changed, 49 insertions, 9 deletions

diff --git a/src/opengl/qgl.cpp b/src/opengl/qgl.cpp
index 65d3bbe..5eb4c16 100644
--- a/src/opengl/qgl.cpp
+++ b/src/opengl/qgl.cpp
@@ -2095,6 +2095,14 @@ QGLContext::QGLContext(const QGLFormat &format)
     d->init(0, format);
 }
 
+QGLContext::QGLContext(QPlatformGLContext *platformContext)
+    : d_ptr(new QGLContextPrivate(this))
+{
+    Q_D(QGLContext);
+    d->init(0,QGLFormat::fromPlatformWindowFormat(platformContext->platformWindowFormat()));
+    d->platformContext = platformContext;
+}
+
 /*!
     Destroys the OpenGL context and frees its resources.
 */
@@ -3152,6 +3160,18 @@ void QGLContext::setDevice(QPaintDevice *pDev)
     }
 }
 
+QGLContext *QGLContext::fromPlatformGLContext(QPlatformGLContext *platformContext)
+{
+    if (!platformContext)
+        return 0;
+    if (platformContext->qGLContextHandle()) {
+        return reinterpret_cast<QGLContext *>(platformContext->qGLContextHandle());
+    }
+    QGLContext *glContext = new QGLContext(platformContext);
+    glContext->create();
+    return glContext;
+}
+
 /*!
     \fn bool QGLContext::isValid() const
 
@@ -3304,11 +3324,16 @@ bool QGLContext::areSharing(const QGLContext *context1, const QGLContext *contex
 bool QGLContext::create(const QGLContext* shareContext)
 {
     Q_D(QGLContext);
+#ifdef Q_WS_QPA
+    if (!d->paintDevice && !d->platformContext)
+#else
     if (!d->paintDevice)
+#endif
         return false;
+
     reset();
     d->valid = chooseContext(shareContext);
-    if (d->valid && d->paintDevice->devType() == QInternal::Widget) {
+    if (d->valid && d->paintDevice && d->paintDevice->devType() == QInternal::Widget) {
         QWidgetPrivate *wd = qt_widget_private(static_cast<QWidget *>(d->paintDevice));
         wd->usesDoubleBufferedGLContext = d->glFormat.doubleBuffer();
     }
@@ -3389,14 +3414,7 @@ const QGLContext* QGLContext::currentContext()
 {
 #ifdef Q_WS_QPA
     if (const QPlatformGLContext *threadContext = QPlatformGLContext::currentContext()) {
-        if (threadContext->qGLContextHandle()) {
-            return (const QGLContext *)threadContext->qGLContextHandle();
-        } else {
-            QWidget *widget  = threadContext->platformWindow()->widget();
-            QGLContext *context = new QGLContext(QGLFormat::fromPlatformWindowFormat(threadContext->platformWindowFormat()),widget);
-            context->create(); //don't know how to pass in the sharecontext. (doesn't really matter though)
-            return context;
-        }
+        return QGLContext::fromPlatformGLContext(const_cast<QPlatformGLContext *>(threadContext));
     }
     return 0;
 #else
@@ -3781,7 +3799,18 @@ QGLWidget::QGLWidget(QWidget *parent, const QGLWidget* shareWidget, Qt::WindowFl
     setAttribute(Qt::WA_PaintOnScreen);
     setAttribute(Qt::WA_NoSystemBackground);
     setAutoFillBackground(true); // for compatibility
+#ifdef Q_WS_QPA
+    setPlatformWindowFormat(QGLFormat::toPlatformWindowFormat(QGLFormat::defaultFormat()));
+    winId(); // create window;
+    QGLContext *glContext = 0;
+    if (platformWindow())
+        glContext = QGLContext::fromPlatformGLContext(platformWindow()->glContext());
+    if (glContext){
+        d->init(glContext,shareWidget);
+    }
+#else
     d->init(new QGLContext(QGLFormat::defaultFormat(), this), shareWidget);
+#endif
 }
 
 
@@ -3821,7 +3850,18 @@ QGLWidget::QGLWidget(const QGLFormat &format, QWidget *parent, const QGLWidget*
     setAttribute(Qt::WA_PaintOnScreen);
     setAttribute(Qt::WA_NoSystemBackground);
     setAutoFillBackground(true); // for compatibility
+#ifdef Q_WS_QPA
+    setPlatformWindowFormat(QGLFormat::toPlatformWindowFormat(QGLFormat::defaultFormat()));
+    winId(); // create window;
+    QGLContext *glContext = 0;
+    if (platformWindow())
+        glContext = QGLContext::fromPlatformGLContext(platformWindow()->glContext());
+    if (glContext){
+        d->init(glContext,shareWidget);
+    }
+#else
     d->init(new QGLContext(format, this), shareWidget);
+#endif
 }
 
 /*!