Modernize the OpenGL examples

Change them to use QOpenGLWidget and QOpenGLTexture.
Advocate also the usage of VBOs.

Hopeless examples, that rely on the fixed pipeline and will
not compile or work in ES and dynamic builds, are moved to
a "legacy" directory. The documentation pages for these are
removed. This long due change avoids the confusion newcomers
experience when trying to get started with Qt 5 and OpenGL.

hellowindow's behavior is changed to open a single window only
by default. The old default behavior, that opened three windows
on platforms that supported both MultipleWindows & ThreadedOpenGL,
can be requested by passing --multiple. --single is removed since it
is the default now. This plays much nicer with drivers that have
issues with threading.

In addition, say hello to hellogl2.

This is the old hellogl example updated to use QOpenGLWidget and
OpenGL 2. It also has a mainwindow with multiple (un)dockable widgets
containing the OpenGL widgets. This helps testing the behavior when
the top-level of the QOpenGLWidget changes and provides a very
important example of how to do proper resource management in this case.
(must use aboutToBeDestroyed() of the context, since the context goes
away and is replaced by a new one on every dock/undock)

As a bonus, the logo is now real 3D, no more orthographic nonsense.

Launch with --multisample to request 4x MSAA.

Launch with --coreprofile to request 3.2 Core. In this particular example
the shaders are present in both versions and there is a VAO so the application
is functional with core profile contexts.

Change-Id: Id780a80cb0708ef164cc172450ed74050f065596
Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com>

10 files changed, 1012 insertions, 0 deletions

diff --git a/examples/opengl/hellogl2/glwidget.cpp b/examples/opengl/hellogl2/glwidget.cpp
new file mode 100644
index 0000000000..c8db3047a1
--- /dev/null
+++ b/examples/opengl/hellogl2/glwidget.cpp
@@ -0,0 +1,283 @@
+/****************************************************************************
+**
+** 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 <QMouseEvent>
+#include <QOpenGLShaderProgram>
+#include <QCoreApplication>
+#include <math.h>
+
+GLWidget::GLWidget(QWidget *parent)
+    : QOpenGLWidget(parent),
+      m_xRot(0),
+      m_yRot(0),
+      m_zRot(0),
+      m_program(0)
+{
+    m_core = QCoreApplication::arguments().contains(QStringLiteral("--coreprofile"));
+}
+
+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()
+{
+    makeCurrent();
+    m_logoVbo.destroy();
+    delete m_program;
+    m_program = 0;
+    doneCurrent();
+}
+
+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();
+
+    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), 0);
+    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->pos();
+}
+
+void GLWidget::mouseMoveEvent(QMouseEvent *event)
+{
+    int dx = event->x() - m_lastPos.x();
+    int dy = event->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->pos();
+}
diff --git a/examples/opengl/hellogl2/glwidget.h b/examples/opengl/hellogl2/glwidget.h
new file mode 100644
index 0000000000..fcc6225999
--- /dev/null
+++ b/examples/opengl/hellogl2/glwidget.h
@@ -0,0 +1,103 @@
+/****************************************************************************
+**
+** 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 <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 = 0);
+    ~GLWidget();
+
+    QSize minimumSizeHint() const Q_DECL_OVERRIDE;
+    QSize sizeHint() const Q_DECL_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() Q_DECL_OVERRIDE;
+    void paintGL() Q_DECL_OVERRIDE;
+    void resizeGL(int width, int height) Q_DECL_OVERRIDE;
+    void mousePressEvent(QMouseEvent *event) Q_DECL_OVERRIDE;
+    void mouseMoveEvent(QMouseEvent *event) Q_DECL_OVERRIDE;
+
+private:
+    void setupVertexAttribs();
+
+    bool m_core;
+    int m_xRot;
+    int m_yRot;
+    int m_zRot;
+    QPoint m_lastPos;
+    Logo m_logo;
+    QOpenGLVertexArrayObject m_vao;
+    QOpenGLBuffer m_logoVbo;
+    QOpenGLShaderProgram *m_program;
+    int m_projMatrixLoc;
+    int m_mvMatrixLoc;
+    int m_normalMatrixLoc;
+    int m_lightPosLoc;
+    QMatrix4x4 m_proj;
+    QMatrix4x4 m_camera;
+    QMatrix4x4 m_world;
+};
+
+#endif
diff --git a/examples/opengl/hellogl2/hellogl2.pro b/examples/opengl/hellogl2/hellogl2.pro
new file mode 100644
index 0000000000..3a52e04d74
--- /dev/null
+++ b/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
+
+# install
+target.path = $$[QT_INSTALL_EXAMPLES]/opengl/hellogl2
+INSTALLS += target
diff --git a/examples/opengl/hellogl2/logo.cpp b/examples/opengl/hellogl2/logo.cpp
new file mode 100644
index 0000000000..1ba47ddfb5
--- /dev/null
+++ b/examples/opengl/hellogl2/logo.cpp
@@ -0,0 +1,141 @@
+/****************************************************************************
+**
+** 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 "logo.h"
+#include <qmath.h>
+
+Logo::Logo()
+    : m_count(0)
+{
+    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);
+}
diff --git a/examples/opengl/hellogl2/logo.h b/examples/opengl/hellogl2/logo.h
new file mode 100644
index 0000000000..29bb7fa241
--- /dev/null
+++ b/examples/opengl/hellogl2/logo.h
@@ -0,0 +1,65 @@
+/****************************************************************************
+**
+** 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 LOGO_H
+#define LOGO_H
+
+#include <qopengl.h>
+#include <QVector>
+#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);
+
+    QVector<GLfloat> m_data;
+    int m_count;
+};
+
+#endif // LOGO_H
diff --git a/examples/opengl/hellogl2/main.cpp b/examples/opengl/hellogl2/main.cpp
new file mode 100644
index 0000000000..2d439878e4
--- /dev/null
+++ b/examples/opengl/hellogl2/main.cpp
@@ -0,0 +1,71 @@
+/****************************************************************************
+**
+** 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 <QDesktopWidget>
+#include <QSurfaceFormat>
+
+#include "mainwindow.h"
+
+int main(int argc, char *argv[])
+{
+    QApplication app(argc, argv);
+
+    QSurfaceFormat fmt;
+    fmt.setDepthBufferSize(24);
+    if (QCoreApplication::arguments().contains(QStringLiteral("--multisample")))
+        fmt.setSamples(4);
+    if (QCoreApplication::arguments().contains(QStringLiteral("--coreprofile"))) {
+        fmt.setVersion(3, 2);
+        fmt.setProfile(QSurfaceFormat::CoreProfile);
+    }
+    QSurfaceFormat::setDefaultFormat(fmt);
+
+    MainWindow mainWindow;
+    mainWindow.resize(mainWindow.sizeHint());
+    int desktopArea = QApplication::desktop()->width() *
+                     QApplication::desktop()->height();
+    int widgetArea = mainWindow.width() * mainWindow.height();
+    if (((float)widgetArea / (float)desktopArea) < 0.75f)
+        mainWindow.show();
+    else
+        mainWindow.showMaximized();
+    return app.exec();
+}
diff --git a/examples/opengl/hellogl2/mainwindow.cpp b/examples/opengl/hellogl2/mainwindow.cpp
new file mode 100644
index 0000000000..ee85cda35c
--- /dev/null
+++ b/examples/opengl/hellogl2/mainwindow.cpp
@@ -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."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#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, SIGNAL(triggered()), this, SLOT(onAddNew()));
+    setMenuBar(menuBar);
+
+    onAddNew();
+}
+
+void MainWindow::onAddNew()
+{
+    if (!centralWidget())
+        setCentralWidget(new Window(this));
+    else
+        QMessageBox::information(0, tr("Cannot add new window"), tr("Already occupied. Undock first."));
+}
diff --git a/examples/opengl/hellogl2/mainwindow.h b/examples/opengl/hellogl2/mainwindow.h
new file mode 100644
index 0000000000..53d4555ce8
--- /dev/null
+++ b/examples/opengl/hellogl2/mainwindow.h
@@ -0,0 +1,57 @@
+/****************************************************************************
+**
+** 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>
+
+class MainWindow : public QMainWindow
+{
+    Q_OBJECT
+
+public:
+    MainWindow();
+
+private slots:
+    void onAddNew();
+};
+
+#endif
diff --git a/examples/opengl/hellogl2/window.cpp b/examples/opengl/hellogl2/window.cpp
new file mode 100644
index 0000000000..0b20870487
--- /dev/null
+++ b/examples/opengl/hellogl2/window.cpp
@@ -0,0 +1,133 @@
+/****************************************************************************
+**
+** 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 "window.h"
+#include "mainwindow.h"
+#include <QSlider>
+#include <QVBoxLayout>
+#include <QHBoxLayout>
+#include <QKeyEvent>
+#include <QPushButton>
+#include <QDesktopWidget>
+#include <QApplication>
+#include <QMessageBox>
+
+Window::Window(MainWindow *mw)
+    : mainWindow(mw)
+{
+    glWidget = new GLWidget;
+
+    xSlider = createSlider();
+    ySlider = createSlider();
+    zSlider = createSlider();
+
+    connect(xSlider, SIGNAL(valueChanged(int)), glWidget, SLOT(setXRotation(int)));
+    connect(glWidget, SIGNAL(xRotationChanged(int)), xSlider, SLOT(setValue(int)));
+    connect(ySlider, SIGNAL(valueChanged(int)), glWidget, SLOT(setYRotation(int)));
+    connect(glWidget, SIGNAL(yRotationChanged(int)), ySlider, SLOT(setValue(int)));
+    connect(zSlider, SIGNAL(valueChanged(int)), glWidget, SLOT(setZRotation(int)));
+    connect(glWidget, SIGNAL(zRotationChanged(int)), zSlider, SLOT(setValue(int)));
+
+    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, SIGNAL(clicked()), this, SLOT(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(0);
+        setAttribute(Qt::WA_DeleteOnClose);
+        move(QApplication::desktop()->width() / 2 - width() / 2,
+             QApplication::desktop()->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(0, tr("Cannot dock"), tr("Main window already closed"));
+            }
+        } else {
+            QMessageBox::information(0, tr("Cannot dock"), tr("Main window already occupied"));
+        }
+    }
+}
diff --git a/examples/opengl/hellogl2/window.h b/examples/opengl/hellogl2/window.h
new file mode 100644
index 0000000000..a850bd6a5a
--- /dev/null
+++ b/examples/opengl/hellogl2/window.h
@@ -0,0 +1,78 @@
+/****************************************************************************
+**
+** 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 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) Q_DECL_OVERRIDE;
+
+private slots:
+    void dockUndock();
+
+private:
+    QSlider *createSlider();
+
+    GLWidget *glWidget;
+    QSlider *xSlider;
+    QSlider *ySlider;
+    QSlider *zSlider;
+    QPushButton *dockBtn;
+    MainWindow *mainWindow;
+};
+
+#endif