11 files changed, 1105 insertions, 0 deletions

diff --git a/tests/manual/examples/opengl/qopenglwidget/CMakeLists.txt b/tests/manual/examples/opengl/qopenglwidget/CMakeLists.txt
new file mode 100644
index 0000000000..d6e9c268ff
--- /dev/null
+++ b/tests/manual/examples/opengl/qopenglwidget/CMakeLists.txt
@@ -0,0 +1,53 @@
+# Copyright (C) 2022 The Qt Company Ltd.
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+cmake_minimum_required(VERSION 3.16)
+project(qopenglwidget LANGUAGES CXX)
+
+if(NOT DEFINED INSTALL_EXAMPLESDIR)
+    set(INSTALL_EXAMPLESDIR "examples")
+endif()
+
+set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/opengl/qopenglwidget")
+
+find_package(Qt6 REQUIRED COMPONENTS Core Gui OpenGL OpenGLWidgets Widgets)
+
+qt_standard_project_setup()
+
+qt_add_executable(qopenglwidget
+    bubble.cpp bubble.h
+    glwidget.cpp glwidget.h
+    main.cpp
+    mainwindow.cpp mainwindow.h
+)
+
+set_target_properties(qopenglwidget PROPERTIES
+    WIN32_EXECUTABLE TRUE
+    MACOSX_BUNDLE TRUE
+)
+
+target_link_libraries(qopenglwidget PRIVATE
+    Qt6::Core
+    Qt6::Gui
+    Qt6::OpenGL
+    Qt6::OpenGLWidgets
+    Qt6::Widgets
+)
+
+# Resources:
+set(texture_resource_files
+    "qt.png"
+)
+
+qt6_add_resources(qopenglwidget "texture"
+    PREFIX
+        "/"
+    FILES
+        ${texture_resource_files}
+)
+
+install(TARGETS qopenglwidget
+    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
+    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
+    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
+)
diff --git a/tests/manual/examples/opengl/qopenglwidget/bubble.cpp b/tests/manual/examples/opengl/qopenglwidget/bubble.cpp
new file mode 100644
index 0000000000..3c32b62113
--- /dev/null
+++ b/tests/manual/examples/opengl/qopenglwidget/bubble.cpp
@@ -0,0 +1,99 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#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();
+    updateBrush();
+}
+
+//! [0]
+void Bubble::updateCache()
+{
+    delete cache;
+    cache = new QImage(qRound(radius * 2 + 2), qRound(radius * 2 + 2), QImage::Format_ARGB32_Premultiplied);
+    cache->fill(0x00000000);
+    QPainter p(cache);
+    p.setRenderHint(QPainter::Antialiasing);
+    QPen pen(Qt::white);
+    pen.setWidth(2);
+    p.setPen(pen);
+    p.setBrush(brush);
+    p.drawEllipse(1, 1, int(2*radius), int(2*radius));
+}
+//! [0]
+
+Bubble::~Bubble()
+{
+    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 + QRandomGenerator::global()->bounded(70));
+    int green = int(185 + QRandomGenerator::global()->bounded(70));
+    int blue = int(205 + QRandomGenerator::global()->bounded(50));
+    int alpha = int(91 + QRandomGenerator::global()->bounded(100));
+
+    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/tests/manual/examples/opengl/qopenglwidget/bubble.h b/tests/manual/examples/opengl/qopenglwidget/bubble.h
new file mode 100644
index 0000000000..47355ead41
--- /dev/null
+++ b/tests/manual/examples/opengl/qopenglwidget/bubble.h
@@ -0,0 +1,39 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#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 = nullptr;
+};
+
+#endif
diff --git a/tests/manual/examples/opengl/qopenglwidget/glwidget.cpp b/tests/manual/examples/opengl/qopenglwidget/glwidget.cpp
new file mode 100644
index 0000000000..e2a3ea4fc5
--- /dev/null
+++ b/tests/manual/examples/opengl/qopenglwidget/glwidget.cpp
@@ -0,0 +1,540 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "glwidget.h"
+#include <QPainter>
+#include <QPaintEngine>
+#include <QOpenGLShaderProgram>
+#include <QOpenGLTexture>
+#include <QRandomGenerator>
+#include <QCoreApplication>
+#include <qmath.h>
+
+#include "mainwindow.h"
+#include "bubble.h"
+
+const int bubbleNum = 8;
+
+#ifndef GL_SRGB8_ALPHA8
+#define GL_SRGB8_ALPHA8 0x8C43
+#endif
+
+GLWidget::GLWidget(MainWindow *maybeMainWindow, const QColor &background)
+    : m_mainWindow(maybeMainWindow),
+      m_background(background)
+{
+    setMinimumSize(300, 250);
+    if (QCoreApplication::arguments().contains(QStringLiteral("--srgb")))
+        setTextureFormat(GL_SRGB8_ALPHA8);
+}
+
+GLWidget::~GLWidget()
+{
+    reset();
+}
+
+void GLWidget::reset()
+{
+    qDeleteAll(m_bubbles);
+    // Leave everything in a state suitable for a subsequent call to
+    // initialize(). This matters when coming from the context's
+    // aboutToBeDestroyed signal, would not matter when invoked from the
+    // destructor.
+    m_bubbles.clear();
+
+    // And now release all OpenGL resources.
+    makeCurrent();
+    delete m_texture;
+    m_texture = nullptr;
+    delete m_program1;
+    m_program1 = nullptr;
+    delete m_program2;
+    m_program2 = nullptr;
+    delete m_vshader1;
+    m_vshader1 = nullptr;
+    delete m_fshader1;
+    m_fshader1 = nullptr;
+    delete m_vshader2;
+    m_vshader2 = nullptr;
+    delete m_fshader2;
+    m_fshader2 = nullptr;
+    m_vbo1.destroy();
+    m_vbo2.destroy();
+    doneCurrent();
+
+    // We are done with the current QOpenGLContext, forget it. If there is a
+    // subsequent initialize(), that will then connect to the new context.
+    QObject::disconnect(m_contextWatchConnection);
+}
+
+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()
+{
+    m_qtLogo = true;
+}
+
+void GLWidget::setTexture()
+{
+    m_qtLogo = false;
+}
+
+void GLWidget::setShowBubbles(bool bubbles)
+{
+    m_showBubbles = bubbles;
+}
+
+void GLWidget::paintQtLogo()
+{
+    m_program1->enableAttributeArray(m_vertexAttr1);
+    m_program1->enableAttributeArray(m_normalAttr1);
+
+    m_vbo1.bind();
+    // The data in the buffer is placed like this:
+    // vertex1.x, vertex1.y, vertex1.z, normal1.x, normal1.y, normal1.z, vertex2.x, ...
+    m_program1->setAttributeBuffer(m_vertexAttr1, GL_FLOAT, 0, 3, 6 * sizeof(GLfloat));
+    m_program1->setAttributeBuffer(m_normalAttr1, GL_FLOAT, 3 * sizeof(GLfloat), 3, 6 * sizeof(GLfloat));
+    m_vbo1.release();
+
+    glDrawArrays(GL_TRIANGLES, 0, m_vertices.size());
+
+    m_program1->disableAttributeArray(m_normalAttr1);
+    m_program1->disableAttributeArray(m_vertexAttr1);
+}
+
+void GLWidget::paintTexturedCube()
+{
+    m_texture->bind();
+
+    if (!m_vbo2.isCreated()) {
+        static 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
+        };
+
+        static 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
+        };
+
+        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
+        };
+
+        m_vbo2.create();
+        m_vbo2.bind();
+        m_vbo2.allocate(36 * 8 * sizeof(GLfloat));
+        m_vbo2.write(0, afVertices, sizeof(afVertices));
+        m_vbo2.write(sizeof(afVertices), afTexCoord, sizeof(afTexCoord));
+        m_vbo2.write(sizeof(afVertices) + sizeof(afTexCoord), afNormals, sizeof(afNormals));
+        m_vbo2.release();
+    }
+
+    m_program2->setUniformValue(m_textureUniform2, 0); // use texture unit 0
+
+    m_program2->enableAttributeArray(m_vertexAttr2);
+    m_program2->enableAttributeArray(m_normalAttr2);
+    m_program2->enableAttributeArray(m_texCoordAttr2);
+
+    m_vbo2.bind();
+    // In the buffer we first have 36 vertices (3 floats for each), then 36 texture
+    // coordinates (2 floats for each), then 36 normals (3 floats for each).
+    m_program2->setAttributeBuffer(m_vertexAttr2, GL_FLOAT, 0, 3);
+    m_program2->setAttributeBuffer(m_texCoordAttr2, GL_FLOAT, 36 * 3 * sizeof(GLfloat), 2);
+    m_program2->setAttributeBuffer(m_normalAttr2, GL_FLOAT, 36 * 5 * sizeof(GLfloat), 3);
+    m_vbo2.release();
+
+    glDrawArrays(GL_TRIANGLES, 0, 36);
+
+    m_program2->disableAttributeArray(m_vertexAttr2);
+    m_program2->disableAttributeArray(m_normalAttr2);
+    m_program2->disableAttributeArray(m_texCoordAttr2);
+}
+
+void GLWidget::initializeGL()
+{
+    initializeOpenGLFunctions();
+
+    m_texture = new QOpenGLTexture(QImage(":/qt.png"));
+
+    m_vshader1 = new QOpenGLShader(QOpenGLShader::Vertex);
+    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";
+    m_vshader1->compileSourceCode(vsrc1);
+
+    m_fshader1 = new QOpenGLShader(QOpenGLShader::Fragment);
+    const char *fsrc1 =
+        "varying mediump vec4 color;\n"
+        "void main(void)\n"
+        "{\n"
+        "    gl_FragColor = color;\n"
+        "}\n";
+    m_fshader1->compileSourceCode(fsrc1);
+
+    m_program1 = new QOpenGLShaderProgram;
+    m_program1->addShader(m_vshader1);
+    m_program1->addShader(m_fshader1);
+    m_program1->link();
+
+    m_vertexAttr1 = m_program1->attributeLocation("vertex");
+    m_normalAttr1 = m_program1->attributeLocation("normal");
+    m_matrixUniform1 = m_program1->uniformLocation("matrix");
+
+    m_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";
+    m_vshader2->compileSourceCode(vsrc2);
+
+    m_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";
+    m_fshader2->compileSourceCode(fsrc2);
+
+    m_program2 = new QOpenGLShaderProgram;
+    m_program2->addShader(m_vshader2);
+    m_program2->addShader(m_fshader2);
+    m_program2->link();
+
+    m_vertexAttr2 = m_program2->attributeLocation("vertex");
+    m_normalAttr2 = m_program2->attributeLocation("normal");
+    m_texCoordAttr2 = m_program2->attributeLocation("texCoord");
+    m_matrixUniform2 = m_program2->uniformLocation("matrix");
+    m_textureUniform2 = m_program2->uniformLocation("tex");
+
+    m_fAngle = 0;
+    m_fScale = 1;
+
+    createGeometry();
+
+    // Use a vertex buffer object. Client-side pointers are old-school and should be avoided.
+    m_vbo1.create();
+    m_vbo1.bind();
+    // For the cube all the data belonging to the texture coordinates and
+    // normals is placed separately, after the vertices. Here, for the Qt logo,
+    // let's do something different and potentially more efficient: create a
+    // properly interleaved data set.
+    const int vertexCount = m_vertices.count();
+    QList<GLfloat> buf;
+    buf.resize(vertexCount * 3 * 2);
+    GLfloat *p = buf.data();
+    for (int i = 0; i < vertexCount; ++i) {
+        *p++ = m_vertices[i].x();
+        *p++ = m_vertices[i].y();
+        *p++ = m_vertices[i].z();
+        *p++ = m_normals[i].x();
+        *p++ = m_normals[i].y();
+        *p++ = m_normals[i].z();
+    }
+    m_vbo1.allocate(buf.constData(), buf.count() * sizeof(GLfloat));
+    m_vbo1.release();
+
+    createBubbles(bubbleNum - m_bubbles.count());
+
+    // A well-behaved QOpenGLWidget releases OpenGL resources not only upon
+    // destruction, but also when the associated OpenGL context disappears. If
+    // the widget continues to exist, the context's destruction will be
+    // followed by a call to initialize(). This is not strictly mandatory in
+    // widgets that never change their parents.
+    m_contextWatchConnection = QObject::connect(context(), &QOpenGLContext::aboutToBeDestroyed, context(), [this] { reset(); });
+}
+
+void GLWidget::paintGL()
+{
+    createBubbles(bubbleNum - m_bubbles.count());
+
+    QPainter painter;
+    painter.begin(this);
+
+    painter.beginNativePainting();
+
+    glClearColor(m_background.redF(), m_background.greenF(), m_background.blueF(), 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 (m_qtLogo) {
+        m_program1->bind();
+        m_program1->setUniformValue(m_matrixUniform1, modelview);
+        paintQtLogo();
+        m_program1->release();
+    } else {
+        m_program2->bind();
+        m_program2->setUniformValue(m_matrixUniform2, modelview);
+        paintTexturedCube();
+        m_program2->release();
+    }
+
+    glDisable(GL_DEPTH_TEST);
+    glDisable(GL_CULL_FACE);
+
+    painter.endNativePainting();
+
+    if (m_showBubbles) {
+        for (Bubble *bubble : std::as_const(m_bubbles))
+            bubble->drawBubble(&painter);
+    }
+
+    if (const int elapsed = m_time.elapsed()) {
+        QString framesPerSecond;
+        framesPerSecond.setNum(m_frames /(elapsed / 1000.0), 'f', 2);
+        painter.setPen(m_transparent ? Qt::black : Qt::white);
+        painter.drawText(20, 40, framesPerSecond + " paintGL calls / s");
+    }
+
+    painter.end();
+
+    for (Bubble *bubble : std::as_const(m_bubbles))
+        bubble->move(rect());
+
+    if (!(m_frames % 100)) {
+        m_time.start();
+        m_frames = 0;
+    }
+    m_fAngle += 1.0f;
+    ++m_frames;
+
+    // When requested, follow the ideal way to animate: Rely on
+    // blocking swap and just schedule updates continuously.
+    if (!m_mainWindow || !m_mainWindow->timerEnabled())
+        update();
+}
+
+void GLWidget::createBubbles(int number)
+{
+    for (int i = 0; i < number; ++i) {
+        QPointF position(width()*(0.1 + QRandomGenerator::global()->bounded(0.8)),
+                         height()*(0.1 + QRandomGenerator::global()->bounded(0.8)));
+        qreal radius = qMin(width(), height())*(0.0175 + QRandomGenerator::global()->bounded(0.0875));
+        QPointF velocity(width()*0.0175*(-0.5 + QRandomGenerator::global()->bounded(1.0)),
+                         height()*0.0175*(-0.5 + QRandomGenerator::global()->bounded(1.0)));
+
+        m_bubbles.append(new Bubble(position, radius, velocity));
+    }
+}
+
+void GLWidget::createGeometry()
+{
+    m_vertices.clear();
+    m_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 int NumSectors = 100;
+    const qreal sectorAngle = 2 * qreal(M_PI) / NumSectors;
+
+    for (int i = 0; i < NumSectors; ++i) {
+        qreal angle = i * sectorAngle;
+        qreal x5 = 0.30 * sin(angle);
+        qreal y5 = 0.30 * cos(angle);
+        qreal x6 = 0.20 * sin(angle);
+        qreal y6 = 0.20 * cos(angle);
+
+        angle += sectorAngle;
+        qreal x7 = 0.20 * sin(angle);
+        qreal y7 = 0.20 * cos(angle);
+        qreal x8 = 0.30 * sin(angle);
+        qreal y8 = 0.30 * cos(angle);
+
+        quad(x5, y5, x6, y6, x7, y7, x8, y8);
+
+        extrude(x6, y6, x7, y7);
+        extrude(x8, y8, x5, y5);
+    }
+
+    for (int i = 0;i < m_vertices.size();i++)
+        m_vertices[i] *= 2.0f;
+}
+
+void GLWidget::quad(qreal x1, qreal y1, qreal x2, qreal y2, qreal x3, qreal y3, qreal x4, qreal y4)
+{
+    m_vertices << QVector3D(x1, y1, -0.05f);
+    m_vertices << QVector3D(x2, y2, -0.05f);
+    m_vertices << QVector3D(x4, y4, -0.05f);
+
+    m_vertices << QVector3D(x3, y3, -0.05f);
+    m_vertices << QVector3D(x4, y4, -0.05f);
+    m_vertices << QVector3D(x2, y2, -0.05f);
+
+    QVector3D n = QVector3D::normal
+        (QVector3D(x2 - x1, y2 - y1, 0.0f), QVector3D(x4 - x1, y4 - y1, 0.0f));
+
+    m_normals << n;
+    m_normals << n;
+    m_normals << n;
+
+    m_normals << n;
+    m_normals << n;
+    m_normals << n;
+
+    m_vertices << QVector3D(x4, y4, 0.05f);
+    m_vertices << QVector3D(x2, y2, 0.05f);
+    m_vertices << QVector3D(x1, y1, 0.05f);
+
+    m_vertices << QVector3D(x2, y2, 0.05f);
+    m_vertices << QVector3D(x4, y4, 0.05f);
+    m_vertices << QVector3D(x3, y3, 0.05f);
+
+    n = QVector3D::normal
+        (QVector3D(x2 - x4, y2 - y4, 0.0f), QVector3D(x1 - x4, y1 - y4, 0.0f));
+
+    m_normals << n;
+    m_normals << n;
+    m_normals << n;
+
+    m_normals << n;
+    m_normals << n;
+    m_normals << n;
+}
+
+void GLWidget::extrude(qreal x1, qreal y1, qreal x2, qreal y2)
+{
+    m_vertices << QVector3D(x1, y1, +0.05f);
+    m_vertices << QVector3D(x2, y2, +0.05f);
+    m_vertices << QVector3D(x1, y1, -0.05f);
+
+    m_vertices << QVector3D(x2, y2, -0.05f);
+    m_vertices << QVector3D(x1, y1, -0.05f);
+    m_vertices << QVector3D(x2, y2, +0.05f);
+
+    QVector3D n = QVector3D::normal
+        (QVector3D(x2 - x1, y2 - y1, 0.0f), QVector3D(0.0f, 0.0f, -0.1f));
+
+    m_normals << n;
+    m_normals << n;
+    m_normals << n;
+
+    m_normals << n;
+    m_normals << n;
+    m_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, int)
+{
+    if (m_mainWindow) {
+        if (!m_btn) {
+            m_btn = new QPushButton("\nAdd widget\n", this);
+            connect(m_btn, &QPushButton::clicked, this, [this] { m_mainWindow->addNew(); });
+        }
+        m_btn->move(20, 80);
+        if (!m_btn2) {
+            m_btn2 = new QPushButton("\nI prefer tabbed widgets\n", this);
+            connect(m_btn2, &QPushButton::clicked, this, [this] { m_mainWindow->showNewWindow(); });
+        }
+        m_btn2->move(20, 160);
+    }
+}
diff --git a/tests/manual/examples/opengl/qopenglwidget/glwidget.h b/tests/manual/examples/opengl/qopenglwidget/glwidget.h
new file mode 100644
index 0000000000..de9d11b94c
--- /dev/null
+++ b/tests/manual/examples/opengl/qopenglwidget/glwidget.h
@@ -0,0 +1,85 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef GLWIDGET_H
+#define GLWIDGET_H
+
+#include <QOpenGLWidget>
+#include <QOpenGLFunctions>
+#include <QOpenGLBuffer>
+#include <QVector3D>
+#include <QMatrix4x4>
+#include <QElapsedTimer>
+#include <QList>
+#include <QPushButton>
+
+class Bubble;
+class MainWindow;
+
+QT_FORWARD_DECLARE_CLASS(QOpenGLTexture)
+QT_FORWARD_DECLARE_CLASS(QOpenGLShader)
+QT_FORWARD_DECLARE_CLASS(QOpenGLShaderProgram)
+
+class GLWidget : public QOpenGLWidget, protected QOpenGLFunctions
+{
+    Q_OBJECT
+public:
+    GLWidget(MainWindow *maybeMainWindow, const QColor &background);
+    ~GLWidget();
+
+public slots:
+    void setScaling(int scale);
+    void setLogo();
+    void setTexture();
+    void setShowBubbles(bool);
+    void setTransparent(bool transparent);
+
+protected:
+    void resizeGL(int w, int h) override;
+    void paintGL() override;
+    void initializeGL() override;
+
+private:
+    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);
+    void reset();
+
+    MainWindow *m_mainWindow;
+    qreal m_fAngle = 0;
+    qreal m_fScale = 1;
+    bool m_showBubbles = true;
+    QList<QVector3D> m_vertices;
+    QList<QVector3D> m_normals;
+    bool m_qtLogo = true;
+    QList<Bubble *> m_bubbles;
+    int m_frames = 0;
+    QElapsedTimer m_time;
+    QOpenGLShader *m_vshader1 = nullptr;
+    QOpenGLShader *m_fshader1 = nullptr;
+    QOpenGLShader *m_vshader2 = nullptr;
+    QOpenGLShader *m_fshader2 = nullptr;
+    QOpenGLShaderProgram *m_program1 = nullptr;
+    QOpenGLShaderProgram *m_program2 = nullptr;
+    QOpenGLTexture *m_texture = nullptr;
+    QOpenGLBuffer m_vbo1;
+    QOpenGLBuffer m_vbo2;
+    int m_vertexAttr1 = 0;
+    int m_normalAttr1 = 0;
+    int m_matrixUniform1 = 0;
+    int m_vertexAttr2 = 0;
+    int m_normalAttr2 = 0;
+    int m_texCoordAttr2 = 0;
+    int m_matrixUniform2 = 0;
+    int m_textureUniform2 = 0;
+    bool m_transparent = false;
+    QPushButton *m_btn = nullptr;
+    QPushButton *m_btn2 = nullptr;
+    QColor m_background;
+    QMetaObject::Connection m_contextWatchConnection;
+};
+
+#endif
diff --git a/tests/manual/examples/opengl/qopenglwidget/main.cpp b/tests/manual/examples/opengl/qopenglwidget/main.cpp
new file mode 100644
index 0000000000..1614649a5a
--- /dev/null
+++ b/tests/manual/examples/opengl/qopenglwidget/main.cpp
@@ -0,0 +1,42 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include <QApplication>
+#include <QMainWindow>
+#include <QColorSpace>
+#include <QSurfaceFormat>
+#include <QCommandLineParser>
+#include <QCommandLineOption>
+#include "mainwindow.h"
+
+int main( int argc, char ** argv )
+{
+    QApplication a( argc, argv );
+
+    QCoreApplication::setApplicationName("Qt QOpenGLWidget Example");
+    QCoreApplication::setOrganizationName("QtProject");
+    QCoreApplication::setApplicationVersion(QT_VERSION_STR);
+    QCommandLineParser parser;
+    parser.setApplicationDescription(QCoreApplication::applicationName());
+    parser.addHelpOption();
+    parser.addVersionOption();
+    QCommandLineOption multipleSampleOption("multisample", "Multisampling");
+    parser.addOption(multipleSampleOption);
+    QCommandLineOption srgbOption("srgb", "Use sRGB Color Space");
+    parser.addOption(srgbOption);
+    parser.process(a);
+
+    QSurfaceFormat format;
+    format.setDepthBufferSize(24);
+    format.setStencilBufferSize(8);
+    if (parser.isSet(srgbOption))
+        format.setColorSpace(QColorSpace::SRgb);
+    if (parser.isSet(multipleSampleOption))
+        format.setSamples(4);
+    QSurfaceFormat::setDefaultFormat(format);
+
+    MainWindow mw;
+    mw.resize(1280, 720);
+    mw.show();
+    return a.exec();
+}
diff --git a/tests/manual/examples/opengl/qopenglwidget/mainwindow.cpp b/tests/manual/examples/opengl/qopenglwidget/mainwindow.cpp
new file mode 100644
index 0000000000..c383a692d5
--- /dev/null
+++ b/tests/manual/examples/opengl/qopenglwidget/mainwindow.cpp
@@ -0,0 +1,188 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "mainwindow.h"
+
+#include <QApplication>
+#include <QMenuBar>
+#include <QGroupBox>
+#include <QSlider>
+#include <QLabel>
+#include <QCheckBox>
+#include <QRandomGenerator>
+#include <QSpinBox>
+#include <QScrollArea>
+#include <QTabWidget>
+#include <QTabBar>
+#include <QToolButton>
+
+#include "glwidget.h"
+
+MainWindow::MainWindow()
+    : m_nextX(1), m_nextY(1)
+{
+    GLWidget *glwidget = new GLWidget(this, qRgb(20, 20, 50));
+    m_glWidgets << glwidget;
+    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 *timerBased = new QCheckBox("Use timer", this);
+    timerBased->setChecked(false);
+    timerBased->setToolTip("Toggles using a timer to trigger update().\n"
+                           "When not set, each paintGL() schedules the next update immediately,\n"
+                           "expecting the blocking swap to throttle the thread.\n"
+                           "This shows how unnecessary the timer is in most cases.");
+    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(timerBased);
+    updateLayout->addWidget(transparent);
+    updateGroupBox->setLayout(updateLayout);
+
+    slider->setRange(0, 50);
+    slider->setSliderPosition(30);
+    m_timer->setInterval(10);
+    label->setText("A scrollable QOpenGLWidget");
+    label->setAlignment(Qt::AlignHCenter);
+
+    QGroupBox * groupBox = new QGroupBox(this);
+    setCentralWidget(groupBox);
+    groupBox->setTitle("QOpenGLWidget Example");
+
+    m_layout = new QGridLayout(groupBox);
+
+    QScrollArea *scrollArea = new QScrollArea;
+    scrollArea->setWidget(glwidget);
+
+    m_layout->addWidget(scrollArea,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 = menuBar()->addMenu("&File");
+    fileMenu->addAction("E&xit", this, &QWidget::close);
+    QMenu *showMenu = menuBar()->addMenu("&Show");
+    showMenu->addAction("Show 3D Logo", glwidget, &GLWidget::setLogo);
+    showMenu->addAction("Show 2D Texture", glwidget, &GLWidget::setTexture);
+    QAction *showBubbles = showMenu->addAction("Show bubbles", glwidget, &GLWidget::setShowBubbles);
+    showBubbles->setCheckable(true);
+    showBubbles->setChecked(true);
+    showMenu->addAction("Open tab window", this, &MainWindow::showNewWindow);
+    QMenu *helpMenu = menuBar()->addMenu("&Help");
+    helpMenu->addAction("About Qt", qApp, &QApplication::aboutQt);
+
+    connect(m_timer, &QTimer::timeout, glwidget, QOverload<>::of(&QWidget::update));
+
+    connect(slider, &QAbstractSlider::valueChanged, glwidget, &GLWidget::setScaling);
+    connect(transparent, &QCheckBox::toggled, glwidget, &GLWidget::setTransparent);
+    connect(updateInterval, &QSpinBox::valueChanged,
+            this, &MainWindow::updateIntervalChanged);
+    connect(timerBased, &QCheckBox::toggled, this, &MainWindow::timerUsageChanged);
+    connect(timerBased, &QCheckBox::toggled, updateInterval, &QWidget::setEnabled);
+
+    if (timerBased->isChecked())
+        m_timer->start();
+    else
+        updateInterval->setEnabled(false);
+}
+
+void MainWindow::updateIntervalChanged(int value)
+{
+    m_timer->setInterval(value);
+    if (m_timer->isActive())
+        m_timer->start();
+}
+
+void MainWindow::addNew()
+{
+    if (m_nextY == 4)
+        return;
+    GLWidget *w = new GLWidget(nullptr, qRgb(QRandomGenerator::global()->bounded(256),
+                                             QRandomGenerator::global()->bounded(256),
+                                             QRandomGenerator::global()->bounded(256)));
+    m_glWidgets << w;
+    connect(m_timer, &QTimer::timeout, w, QOverload<>::of(&QWidget::update));
+    m_layout->addWidget(w, m_nextY, m_nextX, 1, 1);
+    if (m_nextX == 3) {
+        m_nextX = 1;
+        ++m_nextY;
+    } else {
+        ++m_nextX;
+    }
+}
+
+void MainWindow::timerUsageChanged(bool enabled)
+{
+    if (enabled) {
+        m_timer->start();
+    } else {
+        m_timer->stop();
+        for (QOpenGLWidget *w : std::as_const(m_glWidgets))
+            w->update();
+    }
+}
+
+void MainWindow::resizeEvent(QResizeEvent *)
+{
+     m_glWidgets[0]->setMinimumSize(size() + QSize(128, 128));
+}
+
+void MainWindow::showNewWindow()
+{
+    QTabWidget *tabs = new QTabWidget;
+    tabs->resize(800, 600);
+
+    QToolButton *tb = new QToolButton;
+    tb->setText(QLatin1String("+"));
+    tabs->addTab(new QLabel(QLatin1String("Add OpenGL widgets with +")), QString());
+    tabs->setTabEnabled(0, false);
+    tabs->tabBar()->setTabButton(0, QTabBar::RightSide, tb);
+    tabs->tabBar()->setTabsClosable(true);
+    QObject::connect(tabs->tabBar(), &QTabBar::tabCloseRequested, tabs, [tabs](int index) {
+        tabs->widget(index)->deleteLater();
+    });
+
+    const QString msgToTopLevel = QLatin1String("Break out to top-level window");
+    const QString msgFromTopLevel = QLatin1String("Move back under tab widget");
+
+    QObject::connect(tb, &QAbstractButton::clicked, tabs, [=] {
+        GLWidget *glwidget = new GLWidget(nullptr, Qt::blue);
+        glwidget->resize(tabs->size());
+        glwidget->setWindowTitle(QString::asprintf("QOpenGLWidget %p", glwidget));
+
+        QPushButton *btn = new QPushButton(msgToTopLevel, glwidget);
+        connect(btn, &QPushButton::clicked, glwidget, [=] {
+            if (glwidget->parent()) {
+                glwidget->setAttribute(Qt::WA_DeleteOnClose, true);
+                glwidget->setParent(nullptr);
+                glwidget->show();
+                btn->setText(msgFromTopLevel);
+            } else {
+                glwidget->setAttribute(Qt::WA_DeleteOnClose, false);
+                tabs->addTab(glwidget, glwidget->windowTitle());
+                btn->setText(msgToTopLevel);
+            }
+        });
+
+        tabs->setCurrentIndex(tabs->addTab(glwidget, glwidget->windowTitle()));
+    });
+
+    tabs->setAttribute(Qt::WA_DeleteOnClose);
+    tabs->show();
+}
diff --git a/tests/manual/examples/opengl/qopenglwidget/mainwindow.h b/tests/manual/examples/opengl/qopenglwidget/mainwindow.h
new file mode 100644
index 0000000000..85f11ad764
--- /dev/null
+++ b/tests/manual/examples/opengl/qopenglwidget/mainwindow.h
@@ -0,0 +1,39 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef MAINWINDOW_H
+#define MAINWINDOW_H
+
+#include <QMainWindow>
+#include <QTimer>
+#include <QGridLayout>
+
+QT_FORWARD_DECLARE_CLASS(QOpenGLWidget)
+
+class MainWindow : public QMainWindow
+{
+    Q_OBJECT
+
+public:
+    MainWindow();
+    void addNew();
+    bool timerEnabled() const { return m_timer->isActive(); }
+
+    void resizeEvent(QResizeEvent *);
+
+public slots:
+    void showNewWindow();
+
+private slots:
+    void updateIntervalChanged(int value);
+    void timerUsageChanged(bool enabled);
+
+private:
+    QTimer *m_timer;
+    QGridLayout *m_layout;
+    int m_nextX;
+    int m_nextY;
+    QList<QOpenGLWidget *> m_glWidgets;
+};
+
+#endif
diff --git a/tests/manual/examples/opengl/qopenglwidget/qopenglwidget.pro b/tests/manual/examples/opengl/qopenglwidget/qopenglwidget.pro
new file mode 100644
index 0000000000..7ac546d7ce
--- /dev/null
+++ b/tests/manual/examples/opengl/qopenglwidget/qopenglwidget.pro
@@ -0,0 +1,15 @@
+QT += widgets opengl openglwidgets
+
+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/tests/manual/examples/opengl/qopenglwidget/qt.png b/tests/manual/examples/opengl/qopenglwidget/qt.png
new file mode 100644
index 0000000000..4f68e162de
--- /dev/null
+++ b/tests/manual/examples/opengl/qopenglwidget/qt.png
diff --git a/tests/manual/examples/opengl/qopenglwidget/texture.qrc b/tests/manual/examples/opengl/qopenglwidget/texture.qrc
new file mode 100644
index 0000000000..ff1d0e535f
--- /dev/null
+++ b/tests/manual/examples/opengl/qopenglwidget/texture.qrc
@@ -0,0 +1,5 @@
+<!DOCTYPE RCC><RCC version="1.0">
+<qresource>
+    <file>qt.png</file>
+</qresource>
+</RCC>