Make QOpenGLWidget public

QOpenGLWidget is now public.

In addition Qt::WA_AlwaysStackOnTop is introduced to support the
special case of semi-transparent QOpenGLWidget or QQuickWidget on
top of regular widgets.

hellogl_es2 becomes the qopenglwidget example. This example performs
painting both via QPainter and native GL commands and has the OpenGL
widget combined with other, normal widgets.

The widget stack receives some changes when it comes to renderToTexture
widgets like QQuickWidget and QOpenGLWidget. Calling update() will now
result in a paint event, which is essential for QOpenGLWidget since we
want it to behave like a regular widget. The dirty region handling is
extended specially for such widgets due to performance reasons.
(an OpenGL content update must not result in any backingstore painting,
and is thus handled as a different kind of dirtiness)

[ChangeLog] Added QOpenGLWidget. This widget serves as a replacement for QGLWidget.

Task-number: QTBUG-36899
Task-number: QTBUG-40086
Change-Id: Ibf7f82fea99b39edfffd2fc088e7e0eadbca25cf
Reviewed-by: Paul Olav Tvete <paul.tvete@digia.com>

3 files changed, 21 insertions, 5 deletions

diff --git a/tests/manual/qopenglwidget/openglwidget/main.cpp b/tests/manual/qopenglwidget/openglwidget/main.cpp
index 68f9be7199..0268d47767 100644
--- a/tests/manual/qopenglwidget/openglwidget/main.cpp
+++ b/tests/manual/qopenglwidget/openglwidget/main.cpp
@@ -45,20 +45,32 @@
 #include <QMdiArea>
 #include <QLCDNumber>
 #include <QTimer>
-
+#include <QSurfaceFormat>
+#include <QDebug>
 
 int main(int argc, char *argv[])
 {
     QApplication a(argc, argv);
 
+    QSurfaceFormat format;
+    if (QCoreApplication::arguments().contains(QLatin1String("--multisample")))
+        format.setSamples(4);
+    if (QCoreApplication::arguments().contains(QLatin1String("--coreprofile"))) {
+        format.setVersion(3, 2);
+        format.setProfile(QSurfaceFormat::CoreProfile);
+    }
+    qDebug() << "Requesting" << format;
+
     QMdiArea w;
     w.resize(400,400);
 
     OpenGLWidget *glw = new OpenGLWidget;
+    glw->setFormat(format);
     w.addSubWindow(glw);
     glw->setMinimumSize(100,100);
 
     OpenGLWidget *glw2 = new OpenGLWidget;
+    glw2->setFormat(format);
     glw2->setMinimumSize(100,100);
     w.addSubWindow(glw2);
 
@@ -69,5 +81,8 @@ int main(int argc, char *argv[])
 
     w.show();
 
+    if (glw->isValid())
+        qDebug() << "Got" << glw->format();
+
     return a.exec();
 }
diff --git a/tests/manual/qopenglwidget/openglwidget/openglwidget.cpp b/tests/manual/qopenglwidget/openglwidget/openglwidget.cpp
index bec89b6b41..516de35ff8 100644
--- a/tests/manual/qopenglwidget/openglwidget/openglwidget.cpp
+++ b/tests/manual/qopenglwidget/openglwidget/openglwidget.cpp
@@ -58,7 +58,7 @@
 #include <QtCore/qmath.h>
 #include <qopengl.h>
 
-class OpenGLWidgetPrivate
+class OpenGLWidgetPrivate : protected QOpenGLFunctions
 {
 public:
     OpenGLWidgetPrivate(QWidget *q)
@@ -91,7 +91,7 @@ OpenGLWidget::OpenGLWidget(QWidget *parent)
 {
     d = new OpenGLWidgetPrivate(this);
     QTimer *timer = new QTimer(this);
-    connect(timer, SIGNAL(timeout()), this, SLOT(updateGL()));
+    connect(timer, SIGNAL(timeout()), this, SLOT(update()));
     timer->start(30);
 }
 
@@ -137,6 +137,7 @@ static const char *fragmentShaderSource =
 
 void OpenGLWidgetPrivate::initialize()
 {
+    initializeOpenGLFunctions();
     m_program = new QOpenGLShaderProgram;
     m_program->addShaderFromSourceCode(QOpenGLShader::Vertex, vertexShaderSource);
     m_program->addShaderFromSourceCode(QOpenGLShader::Fragment, fragmentShaderSource);
@@ -157,7 +158,7 @@ void OpenGLWidgetPrivate::render()
     m_program->bind();
 
     QMatrix4x4 matrix;
-    matrix.perspective(60, 4.0/3.0, 0.1, 100.0);
+    matrix.perspective(60.0f, 4.0f/3.0f, 0.1f, 100.0f);
     matrix.translate(0, 0, -2);
     matrix.rotate(100.0f * m_frame / 30/*screen()->refreshRate()*/, 0, 1, 0);
 
diff --git a/tests/manual/qopenglwidget/openglwidget/openglwidget.h b/tests/manual/qopenglwidget/openglwidget/openglwidget.h
index eaba27df26..ada01d4cc1 100644
--- a/tests/manual/qopenglwidget/openglwidget/openglwidget.h
+++ b/tests/manual/qopenglwidget/openglwidget/openglwidget.h
@@ -42,7 +42,7 @@
 #ifndef OPENGLWIDGET_H
 #define OPENGLWIDGET_H
 
-#include <QtWidgets/private/qopenglwidget_p.h>
+#include <QtWidgets/QOpenGLWidget>
 
 class OpenGLWidgetPrivate;
 class OpenGLWidget : public QOpenGLWidget