qt 6.5.1 original

examples/opengl/hellogl2/CMakeLists.txt

@@ -0,0 +1,42 @@
+# Copyright (C) 2022 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+cmake_minimum_required(VERSION 3.16)
+project(hellogl2 LANGUAGES CXX)
+
+if(NOT DEFINED INSTALL_EXAMPLESDIR)
+    set(INSTALL_EXAMPLESDIR "examples")
+endif()
+
+set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/opengl/hellogl2")
+
+find_package(Qt6 REQUIRED COMPONENTS Core Gui OpenGL OpenGLWidgets Widgets)
+
+qt_standard_project_setup()
+
+qt_add_executable(hellogl2
+    glwidget.cpp glwidget.h
+    logo.cpp logo.h
+    main.cpp
+    mainwindow.cpp mainwindow.h
+    window.cpp window.h
+)
+
+set_target_properties(hellogl2 PROPERTIES
+    WIN32_EXECUTABLE TRUE
+    MACOSX_BUNDLE TRUE
+)
+
+target_link_libraries(hellogl2 PRIVATE
+    Qt6::Core
+    Qt6::Gui
+    Qt6::OpenGL
+    Qt6::OpenGLWidgets
+    Qt6::Widgets
+)
+
+install(TARGETS hellogl2
+    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
+    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
+    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
+)

examples/opengl/hellogl2/glwidget.cpp

@@ -0,0 +1,257 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "glwidget.h"
+#include <QMouseEvent>
+#include <QOpenGLShaderProgram>
+#include <QCoreApplication>
+#include <math.h>
+
+bool GLWidget::m_transparent = false;
+
+GLWidget::GLWidget(QWidget *parent)
+    : QOpenGLWidget(parent)
+{
+    m_core = QSurfaceFormat::defaultFormat().profile() == QSurfaceFormat::CoreProfile;
+    // --transparent causes the clear color to be transparent. Therefore, on systems that
+    // support it, the widget will become transparent apart from the logo.
+    if (m_transparent) {
+        QSurfaceFormat fmt = format();
+        fmt.setAlphaBufferSize(8);
+        setFormat(fmt);
+    }
+}
+
+GLWidget::~GLWidget()
+{
+    cleanup();
+}
+
+QSize GLWidget::minimumSizeHint() const
+{
+    return QSize(50, 50);
+}
+
+QSize GLWidget::sizeHint() const
+{
+    return QSize(400, 400);
+}
+
+static void qNormalizeAngle(int &angle)
+{
+    while (angle < 0)
+        angle += 360 * 16;
+    while (angle > 360 * 16)
+        angle -= 360 * 16;
+}
+
+void GLWidget::setXRotation(int angle)
+{
+    qNormalizeAngle(angle);
+    if (angle != m_xRot) {
+        m_xRot = angle;
+        emit xRotationChanged(angle);
+        update();
+    }
+}
+
+void GLWidget::setYRotation(int angle)
+{
+    qNormalizeAngle(angle);
+    if (angle != m_yRot) {
+        m_yRot = angle;
+        emit yRotationChanged(angle);
+        update();
+    }
+}
+
+void GLWidget::setZRotation(int angle)
+{
+    qNormalizeAngle(angle);
+    if (angle != m_zRot) {
+        m_zRot = angle;
+        emit zRotationChanged(angle);
+        update();
+    }
+}
+
+void GLWidget::cleanup()
+{
+    if (m_program == nullptr)
+        return;
+    makeCurrent();
+    m_logoVbo.destroy();
+    delete m_program;
+    m_program = nullptr;
+    doneCurrent();
+    QObject::disconnect(context(), &QOpenGLContext::aboutToBeDestroyed, this, &GLWidget::cleanup);
+}
+
+static const char *vertexShaderSourceCore =
+    "#version 150\n"
+    "in vec4 vertex;\n"
+    "in vec3 normal;\n"
+    "out vec3 vert;\n"
+    "out vec3 vertNormal;\n"
+    "uniform mat4 projMatrix;\n"
+    "uniform mat4 mvMatrix;\n"
+    "uniform mat3 normalMatrix;\n"
+    "void main() {\n"
+    "   vert = vertex.xyz;\n"
+    "   vertNormal = normalMatrix * normal;\n"
+    "   gl_Position = projMatrix * mvMatrix * vertex;\n"
+    "}\n";
+
+static const char *fragmentShaderSourceCore =
+    "#version 150\n"
+    "in highp vec3 vert;\n"
+    "in highp vec3 vertNormal;\n"
+    "out highp vec4 fragColor;\n"
+    "uniform highp vec3 lightPos;\n"
+    "void main() {\n"
+    "   highp vec3 L = normalize(lightPos - vert);\n"
+    "   highp float NL = max(dot(normalize(vertNormal), L), 0.0);\n"
+    "   highp vec3 color = vec3(0.39, 1.0, 0.0);\n"
+    "   highp vec3 col = clamp(color * 0.2 + color * 0.8 * NL, 0.0, 1.0);\n"
+    "   fragColor = vec4(col, 1.0);\n"
+    "}\n";
+
+static const char *vertexShaderSource =
+    "attribute vec4 vertex;\n"
+    "attribute vec3 normal;\n"
+    "varying vec3 vert;\n"
+    "varying vec3 vertNormal;\n"
+    "uniform mat4 projMatrix;\n"
+    "uniform mat4 mvMatrix;\n"
+    "uniform mat3 normalMatrix;\n"
+    "void main() {\n"
+    "   vert = vertex.xyz;\n"
+    "   vertNormal = normalMatrix * normal;\n"
+    "   gl_Position = projMatrix * mvMatrix * vertex;\n"
+    "}\n";
+
+static const char *fragmentShaderSource =
+    "varying highp vec3 vert;\n"
+    "varying highp vec3 vertNormal;\n"
+    "uniform highp vec3 lightPos;\n"
+    "void main() {\n"
+    "   highp vec3 L = normalize(lightPos - vert);\n"
+    "   highp float NL = max(dot(normalize(vertNormal), L), 0.0);\n"
+    "   highp vec3 color = vec3(0.39, 1.0, 0.0);\n"
+    "   highp vec3 col = clamp(color * 0.2 + color * 0.8 * NL, 0.0, 1.0);\n"
+    "   gl_FragColor = vec4(col, 1.0);\n"
+    "}\n";
+
+void GLWidget::initializeGL()
+{
+    // In this example the widget's corresponding top-level window can change
+    // several times during the widget's lifetime. Whenever this happens, the
+    // QOpenGLWidget's associated context is destroyed and a new one is created.
+    // Therefore we have to be prepared to clean up the resources on the
+    // aboutToBeDestroyed() signal, instead of the destructor. The emission of
+    // the signal will be followed by an invocation of initializeGL() where we
+    // can recreate all resources.
+    connect(context(), &QOpenGLContext::aboutToBeDestroyed, this, &GLWidget::cleanup);
+
+    initializeOpenGLFunctions();
+    glClearColor(0, 0, 0, m_transparent ? 0 : 1);
+
+    m_program = new QOpenGLShaderProgram;
+    m_program->addShaderFromSourceCode(QOpenGLShader::Vertex, m_core ? vertexShaderSourceCore : vertexShaderSource);
+    m_program->addShaderFromSourceCode(QOpenGLShader::Fragment, m_core ? fragmentShaderSourceCore : fragmentShaderSource);
+    m_program->bindAttributeLocation("vertex", 0);
+    m_program->bindAttributeLocation("normal", 1);
+    m_program->link();
+
+    m_program->bind();
+    m_projMatrixLoc = m_program->uniformLocation("projMatrix");
+    m_mvMatrixLoc = m_program->uniformLocation("mvMatrix");
+    m_normalMatrixLoc = m_program->uniformLocation("normalMatrix");
+    m_lightPosLoc = m_program->uniformLocation("lightPos");
+
+    // Create a vertex array object. In OpenGL ES 2.0 and OpenGL 2.x
+    // implementations this is optional and support may not be present
+    // at all. Nonetheless the below code works in all cases and makes
+    // sure there is a VAO when one is needed.
+    m_vao.create();
+    QOpenGLVertexArrayObject::Binder vaoBinder(&m_vao);
+
+    // Setup our vertex buffer object.
+    m_logoVbo.create();
+    m_logoVbo.bind();
+    m_logoVbo.allocate(m_logo.constData(), m_logo.count() * sizeof(GLfloat));
+
+    // Store the vertex attribute bindings for the program.
+    setupVertexAttribs();
+
+    // Our camera never changes in this example.
+    m_camera.setToIdentity();
+    m_camera.translate(0, 0, -1);
+
+    // Light position is fixed.
+    m_program->setUniformValue(m_lightPosLoc, QVector3D(0, 0, 70));
+
+    m_program->release();
+}
+
+void GLWidget::setupVertexAttribs()
+{
+    m_logoVbo.bind();
+    QOpenGLFunctions *f = QOpenGLContext::currentContext()->functions();
+    f->glEnableVertexAttribArray(0);
+    f->glEnableVertexAttribArray(1);
+    f->glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat),
+                             nullptr);
+    f->glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat),
+                             reinterpret_cast<void *>(3 * sizeof(GLfloat)));
+    m_logoVbo.release();
+}
+
+void GLWidget::paintGL()
+{
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+    glEnable(GL_DEPTH_TEST);
+    glEnable(GL_CULL_FACE);
+
+    m_world.setToIdentity();
+    m_world.rotate(180.0f - (m_xRot / 16.0f), 1, 0, 0);
+    m_world.rotate(m_yRot / 16.0f, 0, 1, 0);
+    m_world.rotate(m_zRot / 16.0f, 0, 0, 1);
+
+    QOpenGLVertexArrayObject::Binder vaoBinder(&m_vao);
+    m_program->bind();
+    m_program->setUniformValue(m_projMatrixLoc, m_proj);
+    m_program->setUniformValue(m_mvMatrixLoc, m_camera * m_world);
+    QMatrix3x3 normalMatrix = m_world.normalMatrix();
+    m_program->setUniformValue(m_normalMatrixLoc, normalMatrix);
+
+    glDrawArrays(GL_TRIANGLES, 0, m_logo.vertexCount());
+
+    m_program->release();
+}
+
+void GLWidget::resizeGL(int w, int h)
+{
+    m_proj.setToIdentity();
+    m_proj.perspective(45.0f, GLfloat(w) / h, 0.01f, 100.0f);
+}
+
+void GLWidget::mousePressEvent(QMouseEvent *event)
+{
+    m_lastPos = event->position().toPoint();
+}
+
+void GLWidget::mouseMoveEvent(QMouseEvent *event)
+{
+    int dx = event->position().toPoint().x() - m_lastPos.x();
+    int dy = event->position().toPoint().y() - m_lastPos.y();
+
+    if (event->buttons() & Qt::LeftButton) {
+        setXRotation(m_xRot + 8 * dy);
+        setYRotation(m_yRot + 8 * dx);
+    } else if (event->buttons() & Qt::RightButton) {
+        setXRotation(m_xRot + 8 * dy);
+        setZRotation(m_zRot + 8 * dx);
+    }
+    m_lastPos = event->position().toPoint();
+}

examples/opengl/hellogl2/glwidget.h

@@ -0,0 +1,70 @@
+// 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 <QOpenGLVertexArrayObject>
+#include <QOpenGLBuffer>
+#include <QMatrix4x4>
+#include "logo.h"
+
+QT_FORWARD_DECLARE_CLASS(QOpenGLShaderProgram)
+
+class GLWidget : public QOpenGLWidget, protected QOpenGLFunctions
+{
+    Q_OBJECT
+
+public:
+    GLWidget(QWidget *parent = nullptr);
+    ~GLWidget();
+
+    static bool isTransparent() { return m_transparent; }
+    static void setTransparent(bool t) { m_transparent = t; }
+
+    QSize minimumSizeHint() const override;
+    QSize sizeHint() const override;
+
+public slots:
+    void setXRotation(int angle);
+    void setYRotation(int angle);
+    void setZRotation(int angle);
+    void cleanup();
+
+signals:
+    void xRotationChanged(int angle);
+    void yRotationChanged(int angle);
+    void zRotationChanged(int angle);
+
+protected:
+    void initializeGL() override;
+    void paintGL() override;
+    void resizeGL(int width, int height) override;
+    void mousePressEvent(QMouseEvent *event) override;
+    void mouseMoveEvent(QMouseEvent *event) override;
+
+private:
+    void setupVertexAttribs();
+
+    bool m_core;
+    int m_xRot = 0;
+    int m_yRot = 0;
+    int m_zRot = 0;
+    QPoint m_lastPos;
+    Logo m_logo;
+    QOpenGLVertexArrayObject m_vao;
+    QOpenGLBuffer m_logoVbo;
+    QOpenGLShaderProgram *m_program = nullptr;
+    int m_projMatrixLoc = 0;
+    int m_mvMatrixLoc = 0;
+    int m_normalMatrixLoc = 0;
+    int m_lightPosLoc = 0;
+    QMatrix4x4 m_proj;
+    QMatrix4x4 m_camera;
+    QMatrix4x4 m_world;
+    static bool m_transparent;
+};
+
+#endif

examples/opengl/hellogl2/hellogl2.pro

@@ -0,0 +1,15 @@
+HEADERS       = glwidget.h \
+                window.h \
+                mainwindow.h \
+                logo.h
+SOURCES       = glwidget.cpp \
+                main.cpp \
+                window.cpp \
+                mainwindow.cpp \
+                logo.cpp
+
+QT += widgets opengl openglwidgets
+
+# install
+target.path = $$[QT_INSTALL_EXAMPLES]/opengl/hellogl2
+INSTALLS += target

examples/opengl/hellogl2/logo.cpp

@@ -0,0 +1,103 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "logo.h"
+#include <qmath.h>
+
+Logo::Logo()
+{
+    m_data.resize(2500 * 6);
+
+    const GLfloat x1 = +0.06f;
+    const GLfloat y1 = -0.14f;
+    const GLfloat x2 = +0.14f;
+    const GLfloat y2 = -0.06f;
+    const GLfloat x3 = +0.08f;
+    const GLfloat y3 = +0.00f;
+    const GLfloat x4 = +0.30f;
+    const GLfloat 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;
+
+    for (int i = 0; i < NumSectors; ++i) {
+        GLfloat angle = (i * 2 * M_PI) / NumSectors;
+        GLfloat angleSin = qSin(angle);
+        GLfloat angleCos = qCos(angle);
+        const GLfloat x5 = 0.30f * angleSin;
+        const GLfloat y5 = 0.30f * angleCos;
+        const GLfloat x6 = 0.20f * angleSin;
+        const GLfloat y6 = 0.20f * angleCos;
+
+        angle = ((i + 1) * 2 * M_PI) / NumSectors;
+        angleSin = qSin(angle);
+        angleCos = qCos(angle);
+        const GLfloat x7 = 0.20f * angleSin;
+        const GLfloat y7 = 0.20f * angleCos;
+        const GLfloat x8 = 0.30f * angleSin;
+        const GLfloat y8 = 0.30f * angleCos;
+
+        quad(x5, y5, x6, y6, x7, y7, x8, y8);
+
+        extrude(x6, y6, x7, y7);
+        extrude(x8, y8, x5, y5);
+    }
+}
+
+void Logo::add(const QVector3D &v, const QVector3D &n)
+{
+    GLfloat *p = m_data.data() + m_count;
+    *p++ = v.x();
+    *p++ = v.y();
+    *p++ = v.z();
+    *p++ = n.x();
+    *p++ = n.y();
+    *p++ = n.z();
+    m_count += 6;
+}
+
+void Logo::quad(GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2, GLfloat x3, GLfloat y3, GLfloat x4, GLfloat y4)
+{
+    QVector3D n = QVector3D::normal(QVector3D(x4 - x1, y4 - y1, 0.0f), QVector3D(x2 - x1, y2 - y1, 0.0f));
+
+    add(QVector3D(x1, y1, -0.05f), n);
+    add(QVector3D(x4, y4, -0.05f), n);
+    add(QVector3D(x2, y2, -0.05f), n);
+
+    add(QVector3D(x3, y3, -0.05f), n);
+    add(QVector3D(x2, y2, -0.05f), n);
+    add(QVector3D(x4, y4, -0.05f), n);
+
+    n = QVector3D::normal(QVector3D(x1 - x4, y1 - y4, 0.0f), QVector3D(x2 - x4, y2 - y4, 0.0f));
+
+    add(QVector3D(x4, y4, 0.05f), n);
+    add(QVector3D(x1, y1, 0.05f), n);
+    add(QVector3D(x2, y2, 0.05f), n);
+
+    add(QVector3D(x2, y2, 0.05f), n);
+    add(QVector3D(x3, y3, 0.05f), n);
+    add(QVector3D(x4, y4, 0.05f), n);
+}
+
+void Logo::extrude(GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2)
+{
+    QVector3D n = QVector3D::normal(QVector3D(0.0f, 0.0f, -0.1f), QVector3D(x2 - x1, y2 - y1, 0.0f));
+
+    add(QVector3D(x1, y1, +0.05f), n);
+    add(QVector3D(x1, y1, -0.05f), n);
+    add(QVector3D(x2, y2, +0.05f), n);
+
+    add(QVector3D(x2, y2, -0.05f), n);
+    add(QVector3D(x2, y2, +0.05f), n);
+    add(QVector3D(x1, y1, -0.05f), n);
+}

examples/opengl/hellogl2/logo.h

@@ -0,0 +1,28 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef LOGO_H
+#define LOGO_H
+
+#include <qopengl.h>
+#include <QList>
+#include <QVector3D>
+
+class Logo
+{
+public:
+    Logo();
+    const GLfloat *constData() const { return m_data.constData(); }
+    int count() const { return m_count; }
+    int vertexCount() const { return m_count / 6; }
+
+private:
+    void quad(GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2, GLfloat x3, GLfloat y3, GLfloat x4, GLfloat y4);
+    void extrude(GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2);
+    void add(const QVector3D &v, const QVector3D &n);
+
+    QList<GLfloat> m_data;
+    int m_count = 0;
+};
+
+#endif // LOGO_H

examples/opengl/hellogl2/main.cpp

@@ -0,0 +1,59 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include <QApplication>
+#include <QSurfaceFormat>
+#include <QScreen>
+#include <QCommandLineParser>
+#include <QCommandLineOption>
+
+#include "glwidget.h"
+#include "mainwindow.h"
+
+int main(int argc, char *argv[])
+{
+    QApplication app(argc, argv);
+
+    QCoreApplication::setApplicationName("Qt Hello GL 2 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 coreProfileOption("coreprofile", "Use core profile");
+    parser.addOption(coreProfileOption);
+    QCommandLineOption transparentOption("transparent", "Transparent window");
+    parser.addOption(transparentOption);
+
+    parser.process(app);
+
+    QSurfaceFormat fmt;
+    fmt.setDepthBufferSize(24);
+    if (parser.isSet(multipleSampleOption))
+        fmt.setSamples(4);
+    if (parser.isSet(coreProfileOption)) {
+        fmt.setVersion(3, 2);
+        fmt.setProfile(QSurfaceFormat::CoreProfile);
+    }
+    QSurfaceFormat::setDefaultFormat(fmt);
+
+    MainWindow mainWindow;
+
+    GLWidget::setTransparent(parser.isSet(transparentOption));
+    if (GLWidget::isTransparent()) {
+        mainWindow.setAttribute(Qt::WA_TranslucentBackground);
+        mainWindow.setAttribute(Qt::WA_NoSystemBackground, false);
+    }
+    mainWindow.resize(mainWindow.sizeHint());
+    int desktopArea = QGuiApplication::primaryScreen()->size().width() *
+                      QGuiApplication::primaryScreen()->size().height();
+    int widgetArea = mainWindow.width() * mainWindow.height();
+    if (((float)widgetArea / (float)desktopArea) < 0.75f)
+        mainWindow.show();
+    else
+        mainWindow.showMaximized();
+    return app.exec();
+}

examples/opengl/hellogl2/mainwindow.cpp

@@ -0,0 +1,30 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "mainwindow.h"
+#include "window.h"
+#include <QMenuBar>
+#include <QMenu>
+#include <QMessageBox>
+
+MainWindow::MainWindow()
+{
+    QMenuBar *menuBar = new QMenuBar;
+    QMenu *menuWindow = menuBar->addMenu(tr("&Window"));
+    QAction *addNew = new QAction(menuWindow);
+    addNew->setText(tr("Add new"));
+    menuWindow->addAction(addNew);
+    connect(addNew, &QAction::triggered, this, &MainWindow::onAddNew);
+    setMenuBar(menuBar);
+
+    onAddNew();
+}
+
+void MainWindow::onAddNew()
+{
+    if (!centralWidget())
+        setCentralWidget(new Window(this));
+    else
+        QMessageBox::information(nullptr, tr("Cannot add new window"),
+                                 tr("Already occupied. Undock first."));
+}

examples/opengl/hellogl2/mainwindow.h

@@ -0,0 +1,20 @@
+// 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>
+
+class MainWindow : public QMainWindow
+{
+    Q_OBJECT
+
+public:
+    MainWindow();
+
+private slots:
+    void onAddNew();
+};
+
+#endif

examples/opengl/hellogl2/window.cpp

@@ -0,0 +1,97 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "glwidget.h"
+#include "window.h"
+#include "mainwindow.h"
+#include <QSlider>
+#include <QVBoxLayout>
+#include <QHBoxLayout>
+#include <QKeyEvent>
+#include <QPushButton>
+#include <QApplication>
+#include <QMessageBox>
+
+Window::Window(MainWindow *mw)
+    : mainWindow(mw)
+{
+    glWidget = new GLWidget;
+
+    xSlider = createSlider();
+    ySlider = createSlider();
+    zSlider = createSlider();
+
+    connect(xSlider, &QSlider::valueChanged, glWidget, &GLWidget::setXRotation);
+    connect(glWidget, &GLWidget::xRotationChanged, xSlider, &QSlider::setValue);
+    connect(ySlider, &QSlider::valueChanged, glWidget, &GLWidget::setYRotation);
+    connect(glWidget, &GLWidget::yRotationChanged, ySlider, &QSlider::setValue);
+    connect(zSlider, &QSlider::valueChanged, glWidget, &GLWidget::setZRotation);
+    connect(glWidget, &GLWidget::zRotationChanged, zSlider, &QSlider::setValue);
+
+    QVBoxLayout *mainLayout = new QVBoxLayout;
+    QHBoxLayout *container = new QHBoxLayout;
+    container->addWidget(glWidget);
+    container->addWidget(xSlider);
+    container->addWidget(ySlider);
+    container->addWidget(zSlider);
+
+    QWidget *w = new QWidget;
+    w->setLayout(container);
+    mainLayout->addWidget(w);
+    dockBtn = new QPushButton(tr("Undock"), this);
+    connect(dockBtn, &QPushButton::clicked, this, &Window::dockUndock);
+    mainLayout->addWidget(dockBtn);
+
+    setLayout(mainLayout);
+
+    xSlider->setValue(15 * 16);
+    ySlider->setValue(345 * 16);
+    zSlider->setValue(0 * 16);
+
+    setWindowTitle(tr("Hello GL"));
+}
+
+QSlider *Window::createSlider()
+{
+    QSlider *slider = new QSlider(Qt::Vertical);
+    slider->setRange(0, 360 * 16);
+    slider->setSingleStep(16);
+    slider->setPageStep(15 * 16);
+    slider->setTickInterval(15 * 16);
+    slider->setTickPosition(QSlider::TicksRight);
+    return slider;
+}
+
+void Window::keyPressEvent(QKeyEvent *e)
+{
+    if (e->key() == Qt::Key_Escape)
+        close();
+    else
+        QWidget::keyPressEvent(e);
+}
+
+void Window::dockUndock()
+{
+    if (parent()) {
+        setParent(nullptr);
+        setAttribute(Qt::WA_DeleteOnClose);
+        move(QGuiApplication::primaryScreen()->size().width() / 2 - width() / 2,
+             QGuiApplication::primaryScreen()->size().height() / 2 - height() / 2);
+        dockBtn->setText(tr("Dock"));
+        show();
+    } else {
+        if (!mainWindow->centralWidget()) {
+            if (mainWindow->isVisible()) {
+                setAttribute(Qt::WA_DeleteOnClose, false);
+                dockBtn->setText(tr("Undock"));
+                mainWindow->setCentralWidget(this);
+            } else {
+                QMessageBox::information(nullptr, tr("Cannot dock"),
+                                         tr("Main window already closed"));
+            }
+        } else {
+            QMessageBox::information(nullptr, tr("Cannot dock"),
+                                     tr("Main window already occupied"));
+        }
+    }
+}

examples/opengl/hellogl2/window.h

@@ -0,0 +1,41 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef WINDOW_H
+#define WINDOW_H
+
+#include <QWidget>
+
+QT_BEGIN_NAMESPACE
+class QSlider;
+class QPushButton;
+QT_END_NAMESPACE
+
+class GLWidget;
+class MainWindow;
+
+class Window : public QWidget
+{
+    Q_OBJECT
+
+public:
+    Window(MainWindow *mw);
+
+protected:
+    void keyPressEvent(QKeyEvent *event) override;
+
+private slots:
+    void dockUndock();
+
+private:
+    QSlider *createSlider();
+
+    GLWidget *glWidget;
+    QSlider *xSlider;
+    QSlider *ySlider;
+    QSlider *zSlider;
+    QPushButton *dockBtn;
+    MainWindow *mainWindow;
+};
+
+#endif