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>

10 files changed, 1106 insertions, 0 deletions

diff --git a/examples/opengl/qopenglwidget/bubble.cpp b/examples/opengl/qopenglwidget/bubble.cpp
new file mode 100644
index 0000000000..bf04c64966
--- /dev/null
+++ b/examples/opengl/qopenglwidget/bubble.cpp
@@ -0,0 +1,139 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
+**     of its contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtWidgets>
+
+#include "bubble.h"
+
+Bubble::Bubble(const QPointF &position, qreal radius, const QPointF &velocity)
+    : position(position), vel(velocity), radius(radius)
+{
+    innerColor = randomColor();
+    outerColor = randomColor();
+    cache = 0;
+    updateBrush();
+}
+
+//! [0]
+void Bubble::updateCache()
+{
+    if (cache)
+        delete cache;
+    cache = new QImage(qRound(radius * 2 + 2), qRound(radius * 2 + 2), QImage::Format_ARGB32);
+    cache->fill(0x00000000);
+    QPainter p(cache);
+    p.setRenderHint(QPainter::HighQualityAntialiasing);
+    QPen pen(Qt::white);
+    pen.setWidth(2);
+    p.setPen(pen);
+    p.setBrush(brush);
+    p.drawEllipse(0, 0, int(2*radius), int(2*radius));
+}
+//! [0]
+
+Bubble::~Bubble()
+{
+    if (cache)
+        delete cache;
+}
+
+void Bubble::updateBrush()
+{
+    QRadialGradient gradient(QPointF(radius, radius), radius,
+                             QPointF(radius*0.5, radius*0.5));
+
+    gradient.setColorAt(0, QColor(255, 255, 255, 255));
+    gradient.setColorAt(0.25, innerColor);
+    gradient.setColorAt(1, outerColor);
+    brush = QBrush(gradient);
+    updateCache();
+}
+
+//! [1]
+void Bubble::drawBubble(QPainter *painter)
+{
+    painter->save();
+    painter->translate(position.x() - radius, position.y() - radius);
+    painter->setOpacity(0.8);
+    painter->drawImage(0, 0, *cache);
+    painter->restore();
+}
+//! [1]
+
+QColor Bubble::randomColor()
+{
+    int red = int(185 + 70.0*qrand()/(RAND_MAX+1.0));
+    int green = int(185 + 70.0*qrand()/(RAND_MAX+1.0));
+    int blue = int(205 + 50.0*qrand()/(RAND_MAX+1.0));
+    int alpha = int(91 + 100.0*qrand()/(RAND_MAX+1.0));
+
+    return QColor(red, green, blue, alpha);
+}
+
+void Bubble::move(const QRect &bbox)
+{
+    position += vel;
+    qreal leftOverflow = position.x() - radius - bbox.left();
+    qreal rightOverflow = position.x() + radius - bbox.right();
+    qreal topOverflow = position.y() - radius - bbox.top();
+    qreal bottomOverflow = position.y() + radius - bbox.bottom();
+
+    if (leftOverflow < 0.0) {
+        position.setX(position.x() - 2 * leftOverflow);
+        vel.setX(-vel.x());
+    } else if (rightOverflow > 0.0) {
+        position.setX(position.x() - 2 * rightOverflow);
+        vel.setX(-vel.x());
+    }
+
+    if (topOverflow < 0.0) {
+        position.setY(position.y() - 2 * topOverflow);
+        vel.setY(-vel.y());
+    } else if (bottomOverflow > 0.0) {
+        position.setY(position.y() - 2 * bottomOverflow);
+        vel.setY(-vel.y());
+    }
+}
+
+QRectF Bubble::rect()
+{
+    return QRectF(position.x() - radius, position.y() - radius,
+                  2 * radius, 2 * radius);
+}
diff --git a/examples/opengl/qopenglwidget/bubble.h b/examples/opengl/qopenglwidget/bubble.h
new file mode 100644
index 0000000000..ea33466ef7
--- /dev/null
+++ b/examples/opengl/qopenglwidget/bubble.h
@@ -0,0 +1,76 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
+**     of its contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef BUBBLE_H
+#define BUBBLE_H
+
+#include <QBrush>
+#include <QColor>
+#include <QPointF>
+#include <QRect>
+#include <QRectF>
+
+QT_FORWARD_DECLARE_CLASS(QPainter)
+
+class Bubble
+{
+public:
+    Bubble(const QPointF &position, qreal radius, const QPointF &velocity);
+    ~Bubble();
+
+    void drawBubble(QPainter *painter);
+    void updateBrush();
+    void move(const QRect &bbox);
+    void updateCache();
+    QRectF rect();
+
+private:
+    QColor randomColor();
+
+    QBrush brush;
+    QPointF position;
+    QPointF vel;
+    qreal radius;
+    QColor innerColor;
+    QColor outerColor;
+    QImage *cache;
+};
+
+#endif
diff --git a/examples/opengl/qopenglwidget/glwidget.cpp b/examples/opengl/qopenglwidget/glwidget.cpp
new file mode 100644
index 0000000000..e95ca363fc
--- /dev/null
+++ b/examples/opengl/qopenglwidget/glwidget.cpp
@@ -0,0 +1,489 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
+**     of its contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "glwidget.h"
+#include <QPainter>
+#include <QPaintEngine>
+#include <math.h>
+
+#include "mainwindow.h"
+#include "bubble.h"
+
+const int bubbleNum = 8;
+
+GLWidget::GLWidget(MainWindow *mw, bool button, const QColor &background)
+    : m_mainWindow(mw),
+      m_transparent(false),
+      m_btn(0),
+      m_hasButton(button),
+      m_background(background)
+{
+    QSurfaceFormat format;
+    format.setDepthBufferSize(24);
+    format.setStencilBufferSize(8);
+    setFormat(format);
+
+    qtLogo = true;
+    frames = 0;
+    m_showBubbles = true;
+    setMinimumSize(300, 250);
+}
+
+GLWidget::~GLWidget()
+{
+}
+
+void GLWidget::setScaling(int scale) {
+
+    if (scale > 30)
+        m_fScale = 1 + qreal(scale - 30) / 30 * 0.25;
+    else if (scale < 30)
+        m_fScale =  1 - (qreal(30 - scale) / 30 * 0.25);
+    else
+      m_fScale = 1;
+}
+
+void GLWidget::setLogo() {
+    qtLogo = true;
+}
+
+void GLWidget::setTexture() {
+    qtLogo = false;
+}
+
+void GLWidget::showBubbles(bool bubbles)
+{
+   m_showBubbles = bubbles;
+}
+
+void GLWidget::paintQtLogo()
+{
+    program1.enableAttributeArray(normalAttr1);
+    program1.enableAttributeArray(vertexAttr1);
+    program1.setAttributeArray(vertexAttr1, vertices.constData());
+    program1.setAttributeArray(normalAttr1, normals.constData());
+    glDrawArrays(GL_TRIANGLES, 0, vertices.size());
+    program1.disableAttributeArray(normalAttr1);
+    program1.disableAttributeArray(vertexAttr1);
+}
+
+void GLWidget::paintTexturedCube()
+{
+    glBindTexture(GL_TEXTURE_2D, m_uiTexture);
+    GLfloat afVertices[] = {
+        -0.5, 0.5, 0.5, 0.5,-0.5,0.5,-0.5,-0.5,0.5,
+        0.5, -0.5, 0.5, -0.5,0.5,0.5,0.5,0.5,0.5,
+        -0.5, -0.5, -0.5, 0.5,-0.5,-0.5,-0.5,0.5,-0.5,
+        0.5, 0.5, -0.5, -0.5,0.5,-0.5,0.5,-0.5,-0.5,
+
+        0.5, -0.5, -0.5, 0.5,-0.5,0.5,0.5,0.5,-0.5,
+        0.5, 0.5, 0.5, 0.5,0.5,-0.5,0.5,-0.5,0.5,
+        -0.5, 0.5, -0.5, -0.5,-0.5,0.5,-0.5,-0.5,-0.5,
+        -0.5, -0.5, 0.5, -0.5,0.5,-0.5,-0.5,0.5,0.5,
+
+        0.5, 0.5,  -0.5, -0.5, 0.5,  0.5,  -0.5,  0.5,  -0.5,
+        -0.5,  0.5,  0.5,  0.5,  0.5,  -0.5, 0.5, 0.5,  0.5,
+        -0.5,  -0.5, -0.5, -0.5, -0.5, 0.5,  0.5, -0.5, -0.5,
+        0.5, -0.5, 0.5,  0.5,  -0.5, -0.5, -0.5,  -0.5, 0.5
+    };
+    program2.setAttributeArray(vertexAttr2, afVertices, 3);
+
+    GLfloat afTexCoord[] = {
+        0.0f,0.0f, 1.0f,1.0f, 1.0f,0.0f,
+        1.0f,1.0f, 0.0f,0.0f, 0.0f,1.0f,
+        1.0f,1.0f, 1.0f,0.0f, 0.0f,1.0f,
+        0.0f,0.0f, 0.0f,1.0f, 1.0f,0.0f,
+
+        1.0f,1.0f, 1.0f,0.0f, 0.0f,1.0f,
+        0.0f,0.0f, 0.0f,1.0f, 1.0f,0.0f,
+        0.0f,0.0f, 1.0f,1.0f, 1.0f,0.0f,
+        1.0f,1.0f, 0.0f,0.0f, 0.0f,1.0f,
+
+        0.0f,1.0f, 1.0f,0.0f, 1.0f,1.0f,
+        1.0f,0.0f, 0.0f,1.0f, 0.0f,0.0f,
+        1.0f,0.0f, 1.0f,1.0f, 0.0f,0.0f,
+        0.0f,1.0f, 0.0f,0.0f, 1.0f,1.0f
+    };
+    program2.setAttributeArray(texCoordAttr2, afTexCoord, 2);
+
+    GLfloat afNormals[] = {
+
+        0,0,-1, 0,0,-1, 0,0,-1,
+        0,0,-1, 0,0,-1, 0,0,-1,
+        0,0,1, 0,0,1, 0,0,1,
+        0,0,1, 0,0,1, 0,0,1,
+
+        -1,0,0, -1,0,0, -1,0,0,
+        -1,0,0, -1,0,0, -1,0,0,
+        1,0,0, 1,0,0, 1,0,0,
+        1,0,0, 1,0,0, 1,0,0,
+
+        0,-1,0, 0,-1,0, 0,-1,0,
+        0,-1,0, 0,-1,0, 0,-1,0,
+        0,1,0, 0,1,0, 0,1,0,
+        0,1,0, 0,1,0, 0,1,0
+    };
+    program2.setAttributeArray(normalAttr2, afNormals, 3);
+
+    program2.setUniformValue(textureUniform2, 0);    // use texture unit 0
+
+    program2.enableAttributeArray(vertexAttr2);
+    program2.enableAttributeArray(normalAttr2);
+    program2.enableAttributeArray(texCoordAttr2);
+
+    glDrawArrays(GL_TRIANGLES, 0, 36);
+
+    program2.disableAttributeArray(vertexAttr2);
+    program2.disableAttributeArray(normalAttr2);
+    program2.disableAttributeArray(texCoordAttr2);
+}
+
+void GLWidget::initializeGL ()
+{
+    initializeOpenGLFunctions();
+
+    glGenTextures(1, &m_uiTexture);
+    QImage img = QImage(":/qt.png").convertToFormat(QImage::Format_RGBA8888);
+    glBindTexture(GL_TEXTURE_2D, m_uiTexture);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, img.width(), img.height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, img.constBits());
+
+    QOpenGLShader *vshader1 = new QOpenGLShader(QOpenGLShader::Vertex, this);
+    const char *vsrc1 =
+        "attribute highp vec4 vertex;\n"
+        "attribute mediump vec3 normal;\n"
+        "uniform mediump mat4 matrix;\n"
+        "varying mediump vec4 color;\n"
+        "void main(void)\n"
+        "{\n"
+        "    vec3 toLight = normalize(vec3(0.0, 0.3, 1.0));\n"
+        "    float angle = max(dot(normal, toLight), 0.0);\n"
+        "    vec3 col = vec3(0.40, 1.0, 0.0);\n"
+        "    color = vec4(col * 0.2 + col * 0.8 * angle, 1.0);\n"
+        "    color = clamp(color, 0.0, 1.0);\n"
+        "    gl_Position = matrix * vertex;\n"
+        "}\n";
+    vshader1->compileSourceCode(vsrc1);
+
+    QOpenGLShader *fshader1 = new QOpenGLShader(QOpenGLShader::Fragment, this);
+    const char *fsrc1 =
+        "varying mediump vec4 color;\n"
+        "void main(void)\n"
+        "{\n"
+        "    gl_FragColor = color;\n"
+        "}\n";
+    fshader1->compileSourceCode(fsrc1);
+
+    program1.addShader(vshader1);
+    program1.addShader(fshader1);
+    program1.link();
+
+    vertexAttr1 = program1.attributeLocation("vertex");
+    normalAttr1 = program1.attributeLocation("normal");
+    matrixUniform1 = program1.uniformLocation("matrix");
+
+    QOpenGLShader *vshader2 = new QOpenGLShader(QOpenGLShader::Vertex);
+    const char *vsrc2 =
+        "attribute highp vec4 vertex;\n"
+        "attribute highp vec4 texCoord;\n"
+        "attribute mediump vec3 normal;\n"
+        "uniform mediump mat4 matrix;\n"
+        "varying highp vec4 texc;\n"
+        "varying mediump float angle;\n"
+        "void main(void)\n"
+        "{\n"
+        "    vec3 toLight = normalize(vec3(0.0, 0.3, 1.0));\n"
+        "    angle = max(dot(normal, toLight), 0.0);\n"
+        "    gl_Position = matrix * vertex;\n"
+        "    texc = texCoord;\n"
+        "}\n";
+    vshader2->compileSourceCode(vsrc2);
+
+    QOpenGLShader *fshader2 = new QOpenGLShader(QOpenGLShader::Fragment);
+    const char *fsrc2 =
+        "varying highp vec4 texc;\n"
+        "uniform sampler2D tex;\n"
+        "varying mediump float angle;\n"
+        "void main(void)\n"
+        "{\n"
+        "    highp vec3 color = texture2D(tex, texc.st).rgb;\n"
+        "    color = color * 0.2 + color * 0.8 * angle;\n"
+        "    gl_FragColor = vec4(clamp(color, 0.0, 1.0), 1.0);\n"
+        "}\n";
+    fshader2->compileSourceCode(fsrc2);
+
+    program2.addShader(vshader2);
+    program2.addShader(fshader2);
+    program2.link();
+
+    vertexAttr2 = program2.attributeLocation("vertex");
+    normalAttr2 = program2.attributeLocation("normal");
+    texCoordAttr2 = program2.attributeLocation("texCoord");
+    matrixUniform2 = program2.uniformLocation("matrix");
+    textureUniform2 = program2.uniformLocation("tex");
+
+    m_fAngle = 0;
+    m_fScale = 1;
+    createGeometry();
+    createBubbles(bubbleNum - bubbles.count());
+}
+
+void GLWidget::paintGL()
+{
+    createBubbles(bubbleNum - bubbles.count());
+
+    QPainter painter;
+    painter.begin(this);
+
+    painter.beginNativePainting();
+
+    glClearColor(m_background.red() / 255.0f, m_background.green() / 255.0f,
+                 m_background.blue() / 255.0f, m_transparent ? 0.0f : 1.0f);
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+    glFrontFace(GL_CW);
+    glCullFace(GL_FRONT);
+    glEnable(GL_CULL_FACE);
+    glEnable(GL_DEPTH_TEST);
+
+    QMatrix4x4 modelview;
+    modelview.rotate(m_fAngle, 0.0f, 1.0f, 0.0f);
+    modelview.rotate(m_fAngle, 1.0f, 0.0f, 0.0f);
+    modelview.rotate(m_fAngle, 0.0f, 0.0f, 1.0f);
+    modelview.scale(m_fScale);
+    modelview.translate(0.0f, -0.2f, 0.0f);
+
+    if (qtLogo) {
+        program1.bind();
+        program1.setUniformValue(matrixUniform1, modelview);
+        paintQtLogo();
+        program1.release();
+    } else {
+        program2.bind();
+        program1.setUniformValue(matrixUniform2, modelview);
+        paintTexturedCube();
+        program2.release();
+    }
+
+    glDisable(GL_DEPTH_TEST);
+    glDisable(GL_CULL_FACE);
+
+    painter.endNativePainting();
+
+    if (m_showBubbles)
+        foreach (Bubble *bubble, bubbles) {
+            bubble->drawBubble(&painter);
+    }
+
+    if (const int elapsed = time.elapsed()) {
+        QString framesPerSecond;
+        framesPerSecond.setNum(frames /(elapsed / 1000.0), 'f', 2);
+        painter.setPen(m_transparent ? Qt::black : Qt::white);
+        painter.drawText(20, 40, framesPerSecond + " paintGL calls / s");
+    }
+
+    painter.end();
+
+    QMutableListIterator<Bubble*> iter(bubbles);
+
+    while (iter.hasNext()) {
+        Bubble *bubble = iter.next();
+        bubble->move(rect());
+    }
+    if (!(frames % 100)) {
+        time.start();
+        frames = 0;
+    }
+    m_fAngle += 1.0f;
+    frames ++;
+}
+
+void GLWidget::createBubbles(int number)
+{
+    for (int i = 0; i < number; ++i) {
+        QPointF position(width()*(0.1 + (0.8*qrand()/(RAND_MAX+1.0))),
+                        height()*(0.1 + (0.8*qrand()/(RAND_MAX+1.0))));
+        qreal radius = qMin(width(), height())*(0.0175 + 0.0875*qrand()/(RAND_MAX+1.0));
+        QPointF velocity(width()*0.0175*(-0.5 + qrand()/(RAND_MAX+1.0)),
+                        height()*0.0175*(-0.5 + qrand()/(RAND_MAX+1.0)));
+
+        bubbles.append(new Bubble(position, radius, velocity));
+    }
+}
+
+void GLWidget::createGeometry()
+{
+    vertices.clear();
+    normals.clear();
+
+    qreal x1 = +0.06f;
+    qreal y1 = -0.14f;
+    qreal x2 = +0.14f;
+    qreal y2 = -0.06f;
+    qreal x3 = +0.08f;
+    qreal y3 = +0.00f;
+    qreal x4 = +0.30f;
+    qreal y4 = +0.22f;
+
+    quad(x1, y1, x2, y2, y2, x2, y1, x1);
+    quad(x3, y3, x4, y4, y4, x4, y3, x3);
+
+    extrude(x1, y1, x2, y2);
+    extrude(x2, y2, y2, x2);
+    extrude(y2, x2, y1, x1);
+    extrude(y1, x1, x1, y1);
+    extrude(x3, y3, x4, y4);
+    extrude(x4, y4, y4, x4);
+    extrude(y4, x4, y3, x3);
+
+    const qreal Pi = 3.14159f;
+    const int NumSectors = 100;
+
+    for (int i = 0; i < NumSectors; ++i) {
+        qreal angle1 = (i * 2 * Pi) / NumSectors;
+        qreal x5 = 0.30 * sin(angle1);
+        qreal y5 = 0.30 * cos(angle1);
+        qreal x6 = 0.20 * sin(angle1);
+        qreal y6 = 0.20 * cos(angle1);
+
+        qreal angle2 = ((i + 1) * 2 * Pi) / NumSectors;
+        qreal x7 = 0.20 * sin(angle2);
+        qreal y7 = 0.20 * cos(angle2);
+        qreal x8 = 0.30 * sin(angle2);
+        qreal y8 = 0.30 * cos(angle2);
+
+        quad(x5, y5, x6, y6, x7, y7, x8, y8);
+
+        extrude(x6, y6, x7, y7);
+        extrude(x8, y8, x5, y5);
+    }
+
+    for (int i = 0;i < vertices.size();i++)
+        vertices[i] *= 2.0f;
+}
+
+void GLWidget::quad(qreal x1, qreal y1, qreal x2, qreal y2, qreal x3, qreal y3, qreal x4, qreal y4)
+{
+    vertices << QVector3D(x1, y1, -0.05f);
+    vertices << QVector3D(x2, y2, -0.05f);
+    vertices << QVector3D(x4, y4, -0.05f);
+
+    vertices << QVector3D(x3, y3, -0.05f);
+    vertices << QVector3D(x4, y4, -0.05f);
+    vertices << QVector3D(x2, y2, -0.05f);
+
+    QVector3D n = QVector3D::normal
+        (QVector3D(x2 - x1, y2 - y1, 0.0f), QVector3D(x4 - x1, y4 - y1, 0.0f));
+
+    normals << n;
+    normals << n;
+    normals << n;
+
+    normals << n;
+    normals << n;
+    normals << n;
+
+    vertices << QVector3D(x4, y4, 0.05f);
+    vertices << QVector3D(x2, y2, 0.05f);
+    vertices << QVector3D(x1, y1, 0.05f);
+
+    vertices << QVector3D(x2, y2, 0.05f);
+    vertices << QVector3D(x4, y4, 0.05f);
+    vertices << QVector3D(x3, y3, 0.05f);
+
+    n = QVector3D::normal
+        (QVector3D(x2 - x4, y2 - y4, 0.0f), QVector3D(x1 - x4, y1 - y4, 0.0f));
+
+    normals << n;
+    normals << n;
+    normals << n;
+
+    normals << n;
+    normals << n;
+    normals << n;
+}
+
+void GLWidget::extrude(qreal x1, qreal y1, qreal x2, qreal y2)
+{
+    vertices << QVector3D(x1, y1, +0.05f);
+    vertices << QVector3D(x2, y2, +0.05f);
+    vertices << QVector3D(x1, y1, -0.05f);
+
+    vertices << QVector3D(x2, y2, -0.05f);
+    vertices << QVector3D(x1, y1, -0.05f);
+    vertices << QVector3D(x2, y2, +0.05f);
+
+    QVector3D n = QVector3D::normal
+        (QVector3D(x2 - x1, y2 - y1, 0.0f), QVector3D(0.0f, 0.0f, -0.1f));
+
+    normals << n;
+    normals << n;
+    normals << n;
+
+    normals << n;
+    normals << n;
+    normals << n;
+}
+
+void GLWidget::setTransparent(bool transparent)
+{
+    setAttribute(Qt::WA_AlwaysStackOnTop, transparent);
+    m_transparent = transparent;
+    // Call update() on the top-level window after toggling AlwayStackOnTop to make sure
+    // the entire backingstore is updated accordingly.
+    window()->update();
+}
+
+void GLWidget::resizeGL(int w, int h)
+{
+    if (m_hasButton) {
+        if (!m_btn) {
+            m_btn = new QPushButton("A widget on top.\nPress me!", this);
+            connect(m_btn, &QPushButton::clicked, this, &GLWidget::handleButtonPress);
+        }
+        m_btn->move(w / 2, h / 2);
+    }
+}
+
+void GLWidget::handleButtonPress()
+{
+    m_mainWindow->addNew();
+}
diff --git a/examples/opengl/qopenglwidget/glwidget.h b/examples/opengl/qopenglwidget/glwidget.h
new file mode 100644
index 0000000000..6c43ac1576
--- /dev/null
+++ b/examples/opengl/qopenglwidget/glwidget.h
@@ -0,0 +1,112 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
+**     of its contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef GLWIDGET_H
+#define GLWIDGET_H
+
+#include <QOpenGLWidget>
+#include <QOpenGLFunctions>
+#include <QOpenGLShaderProgram>
+#include <QVector3D>
+#include <QMatrix4x4>
+#include <QTime>
+#include <QVector>
+#include <QPushButton>
+
+class Bubble;
+class MainWindow;
+
+class GLWidget : public QOpenGLWidget, protected QOpenGLFunctions
+{
+    Q_OBJECT
+public:
+    GLWidget(MainWindow *mw, bool button, const QColor &background);
+    ~GLWidget();
+
+public slots:
+    void setScaling(int scale);
+    void setLogo();
+    void setTexture();
+    void showBubbles(bool);
+    void setTransparent(bool transparent);
+
+private slots:
+    void handleButtonPress();
+
+protected:
+    void resizeGL(int w, int h) Q_DECL_OVERRIDE;
+    void paintGL() Q_DECL_OVERRIDE;
+    void initializeGL() Q_DECL_OVERRIDE;
+
+private:
+    MainWindow *m_mainWindow;
+    GLuint m_uiTexture;
+    qreal m_fAngle;
+    qreal m_fScale;
+    bool m_showBubbles;
+    void paintTexturedCube();
+    void paintQtLogo();
+    void createGeometry();
+    void createBubbles(int number);
+    void quad(qreal x1, qreal y1, qreal x2, qreal y2, qreal x3, qreal y3, qreal x4, qreal y4);
+    void extrude(qreal x1, qreal y1, qreal x2, qreal y2);
+    QVector<QVector3D> vertices;
+    QVector<QVector3D> normals;
+    bool qtLogo;
+    QList<Bubble*> bubbles;
+    int frames;
+    QTime time;
+    QOpenGLShaderProgram program1;
+    QOpenGLShaderProgram program2;
+    int vertexAttr1;
+    int normalAttr1;
+    int matrixUniform1;
+    int vertexAttr2;
+    int normalAttr2;
+    int texCoordAttr2;
+    int matrixUniform2;
+    int textureUniform2;
+    bool m_transparent;
+    QPushButton *m_btn;
+    bool m_hasButton;
+    QColor m_background;
+};
+
+#endif
diff --git a/examples/opengl/qopenglwidget/main.cpp b/examples/opengl/qopenglwidget/main.cpp
new file mode 100644
index 0000000000..2156e60155
--- /dev/null
+++ b/examples/opengl/qopenglwidget/main.cpp
@@ -0,0 +1,52 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
+**     of its contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QApplication>
+#include <QMainWindow>
+#include "mainwindow.h"
+
+int main( int argc, char ** argv )
+{
+    Q_INIT_RESOURCE(texture);
+    QApplication a( argc, argv );
+    MainWindow mw;
+    mw.showMaximized();
+    return a.exec();
+}
diff --git a/examples/opengl/qopenglwidget/mainwindow.cpp b/examples/opengl/qopenglwidget/mainwindow.cpp
new file mode 100644
index 0000000000..f09acacaf0
--- /dev/null
+++ b/examples/opengl/qopenglwidget/mainwindow.cpp
@@ -0,0 +1,152 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
+**     of its contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "mainwindow.h"
+
+#include <QApplication>
+#include <QMenuBar>
+#include <QGroupBox>
+#include <QSlider>
+#include <QLabel>
+#include <QCheckBox>
+#include <QSpinBox>
+
+#include "glwidget.h"
+
+MainWindow::MainWindow()
+    : m_nextX(1), m_nextY(1)
+{
+    GLWidget *glwidget = new GLWidget(this, true, qRgb(20, 20, 50));
+    QLabel *label = new QLabel(this);
+    m_timer = new QTimer(this);
+    QSlider *slider = new QSlider(this);
+    slider->setOrientation(Qt::Horizontal);
+
+    QLabel *updateLabel = new QLabel("Update interval");
+    QSpinBox *updateInterval = new QSpinBox(this);
+    updateInterval->setSuffix(" ms");
+    updateInterval->setValue(10);
+    updateInterval->setToolTip("Interval for the timer that calls update().\n"
+                               "Note that on most systems the swap will block to wait for vsync\n"
+                               "and therefore an interval < 16 ms will likely lead to a 60 FPS update rate.");
+    QGroupBox *updateGroupBox = new QGroupBox(this);
+    QCheckBox *transparent = new QCheckBox("Transparent background", this);
+    transparent->setToolTip("Toggles Qt::WA_AlwaysStackOnTop and transparent clear color for glClear().\n"
+                            "Note how the button on top stacks incorrectly when enabling this.");
+    QHBoxLayout *updateLayout = new QHBoxLayout;
+    updateLayout->addWidget(updateLabel);
+    updateLayout->addWidget(updateInterval);
+    updateLayout->addWidget(transparent);
+    updateGroupBox->setLayout(updateLayout);
+
+    slider->setRange(0, 50);
+    slider->setSliderPosition(30);
+    m_timer->setInterval(10);
+    label->setText("A QOpenGLWidget");
+    label->setAlignment(Qt::AlignHCenter);
+
+    QGroupBox * groupBox = new QGroupBox(this);
+    setCentralWidget(groupBox);
+    groupBox->setTitle("QOpenGLWidget Example");
+
+    m_layout = new QGridLayout(groupBox);
+
+    m_layout->addWidget(glwidget,1,0,8,1);
+    m_layout->addWidget(label,9,0,1,1);
+    m_layout->addWidget(updateGroupBox, 10, 0, 1, 1);
+    m_layout->addWidget(slider, 11,0,1,1);
+
+    groupBox->setLayout(m_layout);
+
+    QMenu *fileMenu = new QMenu("&File");
+    QMenu *helpMenu = new QMenu("&Help");
+    QMenu *showMenu = new QMenu("&Show");
+    menuBar()->addMenu(fileMenu);
+    menuBar()->addMenu(showMenu);
+    menuBar()->addMenu(helpMenu);
+    QAction *exit = new QAction("E&xit", fileMenu);
+    QAction *aboutQt = new QAction("About Qt", helpMenu);
+    QAction *showLogo = new QAction("Show 3D Logo", showMenu);
+    QAction *showTexture = new QAction("Show 2D Texture", showMenu);
+    QAction *showBubbles = new QAction("Show bubbles", showMenu);
+    showBubbles->setCheckable(true);
+    showBubbles->setChecked(true);
+    fileMenu->addAction(exit);
+    helpMenu->addAction(aboutQt);
+    showMenu->addAction(showLogo);
+    showMenu->addAction(showTexture);
+    showMenu->addAction(showBubbles);
+
+    connect(exit, SIGNAL(triggered(bool)), this, SLOT(close()));
+    connect(aboutQt, SIGNAL(triggered(bool)), qApp, SLOT(aboutQt()));
+
+    connect(m_timer, SIGNAL(timeout()), glwidget, SLOT(update()));
+
+    connect(showLogo, SIGNAL(triggered(bool)), glwidget, SLOT(setLogo()));
+    connect(showTexture, SIGNAL(triggered(bool)), glwidget, SLOT(setTexture()));
+    connect(showBubbles, SIGNAL(triggered(bool)), glwidget, SLOT(showBubbles(bool)));
+    connect(slider, SIGNAL(valueChanged(int)), glwidget, SLOT(setScaling(int)));
+    connect(transparent, &QCheckBox::toggled, glwidget, &GLWidget::setTransparent);
+
+    connect(updateInterval, SIGNAL(valueChanged(int)), this, SLOT(updateIntervalChanged(int)));
+
+    m_timer->start();
+}
+
+void MainWindow::updateIntervalChanged(int value)
+{
+    m_timer->setInterval(value);
+    m_timer->start();
+}
+
+void MainWindow::addNew()
+{
+    if (m_nextY == 4)
+        return;
+    GLWidget *w = new GLWidget(this, false, qRgb(qrand() % 256, qrand() % 256, qrand() % 256));
+    connect(m_timer, SIGNAL(timeout()), w, SLOT(update()));
+    m_layout->addWidget(w, m_nextY, m_nextX, 1, 1);
+    if (m_nextX == 3) {
+        m_nextX = 1;
+        ++m_nextY;
+    } else {
+        ++m_nextX;
+    }
+}
diff --git a/examples/opengl/qopenglwidget/mainwindow.h b/examples/opengl/qopenglwidget/mainwindow.h
new file mode 100644
index 0000000000..9db3e8cbec
--- /dev/null
+++ b/examples/opengl/qopenglwidget/mainwindow.h
@@ -0,0 +1,66 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
+**     of its contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef MAINWINDOW_H
+#define MAINWINDOW_H
+
+#include <QMainWindow>
+#include <QTimer>
+#include <QGridLayout>
+
+class MainWindow : public QMainWindow
+{
+    Q_OBJECT
+
+public:
+    MainWindow();
+    void addNew();
+
+private slots:
+    void updateIntervalChanged(int value);
+
+private:
+    QTimer *m_timer;
+    QGridLayout *m_layout;
+    int m_nextX;
+    int m_nextY;
+};
+
+#endif
diff --git a/examples/opengl/qopenglwidget/qopenglwidget.pro b/examples/opengl/qopenglwidget/qopenglwidget.pro
new file mode 100644
index 0000000000..0165285c02
--- /dev/null
+++ b/examples/opengl/qopenglwidget/qopenglwidget.pro
@@ -0,0 +1,15 @@
+QT += widgets
+
+SOURCES += main.cpp \
+           glwidget.cpp \
+           mainwindow.cpp \
+           bubble.cpp
+
+HEADERS += glwidget.h \
+           mainwindow.h \
+           bubble.h
+
+RESOURCES += texture.qrc
+
+target.path = $$[QT_INSTALL_EXAMPLES]/opengl/qopenglwidget
+INSTALLS += target
diff --git a/examples/opengl/qopenglwidget/qt.png b/examples/opengl/qopenglwidget/qt.png
new file mode 100644
index 0000000000..79e383cf50
--- /dev/null
+++ b/examples/opengl/qopenglwidget/qt.png
diff --git a/examples/opengl/qopenglwidget/texture.qrc b/examples/opengl/qopenglwidget/texture.qrc
new file mode 100644
index 0000000000..ff1d0e535f
--- /dev/null
+++ b/examples/opengl/qopenglwidget/texture.qrc
@@ -0,0 +1,5 @@
+<!DOCTYPE RCC><RCC version="1.0">
+<qresource>
+    <file>qt.png</file>
+</qresource>
+</RCC>