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>

6 files changed, 0 insertions, 394 deletions

diff --git a/examples/opengl/framebufferobject2/cubelogo.png b/examples/opengl/framebufferobject2/cubelogo.png
deleted file mode 100644
index 3ae0f9ba3f..0000000000
--- a/examples/opengl/framebufferobject2/cubelogo.png
+++ /dev/null
diff --git a/examples/opengl/framebufferobject2/framebufferobject2.pro b/examples/opengl/framebufferobject2/framebufferobject2.pro
deleted file mode 100644
index e0067cf27f..0000000000
--- a/examples/opengl/framebufferobject2/framebufferobject2.pro
+++ /dev/null
@@ -1,15 +0,0 @@
-HEADERS += glwidget.h
-SOURCES += glwidget.cpp main.cpp
-RESOURCES += framebufferobject2.qrc
-
-QT += opengl widgets
-
-# install
-target.path = $$[QT_INSTALL_EXAMPLES]/opengl/framebufferobject2
-INSTALLS += target
-
-contains(QT_CONFIG, opengles.) {
-    contains(QT_CONFIG, angle): \
-        warning("Qt was built with ANGLE, which provides only OpenGL ES 2.0 on top of DirectX 9.0c")
-    error("This example requires Qt to be configured with -opengl desktop")
-}
diff --git a/examples/opengl/framebufferobject2/framebufferobject2.qrc b/examples/opengl/framebufferobject2/framebufferobject2.qrc
deleted file mode 100644
index 9fc1a56a1a..0000000000
--- a/examples/opengl/framebufferobject2/framebufferobject2.qrc
+++ /dev/null
@@ -1,5 +0,0 @@
-<!DOCTYPE RCC><RCC version="1.0">
-<qresource prefix="/res">
-   <file>cubelogo.png</file>
-</qresource>
-</RCC>
diff --git a/examples/opengl/framebufferobject2/glwidget.cpp b/examples/opengl/framebufferobject2/glwidget.cpp
deleted file mode 100644
index 32b9799a4a..0000000000
--- a/examples/opengl/framebufferobject2/glwidget.cpp
+++ /dev/null
@@ -1,248 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2013 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 <QtGui/QImage>
-
-#include <math.h>
-
-static GLint cubeArray[][3] = {
-    {0, 0, 0}, {0, 1, 0}, {1, 1, 0}, {1, 0, 0},
-    {0, 0, 1}, {1, 0, 1}, {1, 1, 1}, {0, 1, 1},
-    {0, 0, 0}, {1, 0, 0}, {1, 0, 1}, {0, 0, 1},
-    {0, 1, 0}, {0, 1, 1}, {1, 1, 1}, {1, 1, 0},
-    {0, 1, 0}, {0, 0, 0}, {0, 0, 1}, {0, 1, 1},
-    {1, 0, 0}, {1, 1, 0}, {1, 1, 1}, {1, 0, 1}
-};
-
-static GLint cubeTextureArray[][2] = {
-    {0, 0}, {1, 0}, {1, 1}, {0, 1},
-    {0, 0}, {0, 1}, {1, 1}, {1, 0},
-    {0, 0}, {1, 0}, {1, 1}, {0, 1},
-    {1, 0}, {0, 0}, {0, 1}, {1, 1},
-    {0, 0}, {1, 0}, {1, 1}, {0, 1},
-    {1, 0}, {0, 0}, {0, 1}, {1, 1}
-};
-
-static GLint faceArray[][2] = {
-    {1, -1}, {1, 1}, {-1, 1}, {-1, -1}
-};
-
-static GLubyte colorArray[][4] = {
-    {102, 176, 54, 255},
-    {81, 141, 41, 255},
-    {62, 108, 32, 255},
-    {45, 79, 23, 255}
-};
-
-GLWidget::GLWidget(QWidget *parent)
-  : QGLWidget(QGLFormat(QGL::SampleBuffers), parent)
-{
-    // create the framebuffer object - make sure to have a current
-    // context before creating it
-    makeCurrent();
-    fbo = new QGLFramebufferObject(512, 512);
-    timerId = startTimer(20);
-    setWindowTitle(tr("OpenGL framebuffer objects 2"));
-}
-
-GLWidget::~GLWidget()
-{
-    glDeleteLists(pbufferList, 1);
-    delete fbo;
-}
-
-void GLWidget::initializeGL()
-{
-    glMatrixMode(GL_MODELVIEW);
-
-    glEnable(GL_CULL_FACE);
-
-    glEnableClientState(GL_VERTEX_ARRAY);
-    glEnableClientState(GL_TEXTURE_COORD_ARRAY);
-    glVertexPointer(3, GL_INT, 0, cubeArray);
-    glTexCoordPointer(2, GL_INT, 0, cubeTextureArray);
-    glColorPointer(4, GL_UNSIGNED_BYTE, 0, colorArray);
-
-    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-    glEnable(GL_BLEND);
-    glEnable(GL_TEXTURE_2D);
-    glEnable(GL_DEPTH_TEST);
-
-    glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
-    pbufferList = glGenLists(1);
-    glNewList(pbufferList, GL_COMPILE);
-    {
-        glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
-
-        // draw cube background
-        glPushMatrix();
-        glLoadIdentity();
-        glTranslatef(0.5f, 0.5f, -2.0f);
-        glDisable(GL_TEXTURE_2D);
-        glEnableClientState(GL_COLOR_ARRAY);
-        glVertexPointer(2, GL_INT, 0, faceArray);
-        glDrawArrays(GL_QUADS, 0, 4);
-        glVertexPointer(3, GL_INT, 0, cubeArray);
-        glDisableClientState(GL_COLOR_ARRAY);
-        glEnable(GL_TEXTURE_2D);
-        glPopMatrix();
-
-        // draw cube
-        glTranslatef(0.5f, 0.5f, 0.5f);
-        glRotatef(3.0f, 1.0f, 1.0f, 1.0f);
-        glTranslatef(-0.5f, -0.5f, -0.5f);
-        glColor4f(0.9f, 0.9f, 0.9f, 1.0f);
-        glDrawArrays(GL_QUADS, 0, 24);
-
-        glPushMatrix(); // this state is popped back in the paintGL() function
-    }
-    glEndList();
-
-    for (int i = 0; i < 3; ++i) {
-        yOffs[i] = 0.0f;
-        xInc[i] = 0.005f;
-        rot[i] = 0.0f;
-    }
-    xOffs[0]= 0.0f;
-    xOffs[1]= 0.5f;
-    xOffs[2]= 1.0f;
-
-    cubeTexture = bindTexture(QImage(":res/cubelogo.png"));
-
-    glPushMatrix(); // push to avoid stack underflow in the first paintGL() call
-}
-
-void GLWidget::resizeGL(int w, int h)
-{
-    glViewport(0, 0, w, h);
-    glMatrixMode(GL_PROJECTION);
-    glLoadIdentity();
-    float aspect = w/(float)(h ? h : 1);
-    glFrustum(-aspect, aspect, -1, 1, 10, 100);
-    glTranslatef(-0.5f, -0.5f, -0.5f);
-    glTranslatef(0.0f, 0.0f, -15.0f);
-}
-
-void GLWidget::paintGL()
-{
-    glPopMatrix(); // pop the matrix pushed in the pbuffer list
-
-    // push the projection matrix and the entire GL state before
-    // doing any rendering into our framebuffer object
-    glPushAttrib(GL_ALL_ATTRIB_BITS);
-    glMatrixMode(GL_PROJECTION);
-    glPushMatrix();
-
-    glViewport(0, 0, fbo->size().width(), fbo->size().height());
-    glMatrixMode(GL_PROJECTION);
-    glLoadIdentity();
-    glOrtho(-1, 1, -1, 1, -99, 99);
-    glTranslatef(-0.5f, -0.5f, 0.0f);
-    glMatrixMode(GL_MODELVIEW);
-
-    // render to the framebuffer object
-    fbo->bind();
-    glBindTexture(GL_TEXTURE_2D, cubeTexture);
-    glCallList(pbufferList);
-    fbo->release();
-
-    // pop the projection matrix and GL state back for rendering
-    // to the actual widget
-    glPopAttrib();
-    glMatrixMode(GL_PROJECTION);
-    glPopMatrix();
-
-    glBindTexture(GL_TEXTURE_2D, fbo->texture());
-    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-
-    // draw the background
-    glMatrixMode(GL_MODELVIEW);
-    glPushMatrix();
-    glLoadIdentity();
-    glMatrixMode(GL_PROJECTION);
-    glPushMatrix();
-    glLoadIdentity();
-
-    glVertexPointer(2, GL_INT, 0, faceArray);
-    glTranslatef(-1.2f, -0.8f, 0.0f);
-    glScalef(0.2f, 0.2f, 0.2f);
-    for (int y = 0; y < 5; ++y) {
-        for (int x = 0; x < 5; ++x) {
-            glTranslatef(2.0f, 0, 0);
-            glColor4f(0.8f, 0.8f, 0.8f, 1.0f);
-            glDrawArrays(GL_QUADS, 0, 4);
-        }
-        glTranslatef(-10.0f, 2.0f, 0);
-    }
-    glVertexPointer(3, GL_INT, 0, cubeArray);
-
-    glPopMatrix();
-    glMatrixMode(GL_MODELVIEW);
-
-    // draw the bouncing cubes
-    drawCube(0, 0.0f, 1.5f, 2.5f, 1.5f);
-    drawCube(1, 1.0f, 2.0f, 2.5f, 2.0f);
-    drawCube(2, 2.0f, 3.5f, 2.5f, 2.5f);
-    glPopMatrix();
-}
-
-void GLWidget::drawCube(int i, GLfloat z, GLfloat rotation, GLfloat jmp, GLfloat amp)
-{
-    glMatrixMode(GL_MODELVIEW);
-    glLoadIdentity();
-    glTranslatef(xOffs[i], yOffs[i], z);
-    glTranslatef(0.5f, 0.5f, 0.5f);
-    GLfloat scale = 0.75 + i*(0.25f/2);
-    glScalef(scale, scale, scale);
-    glRotatef(rot[i], 1.0f, 1.0f, 1.0f);
-    glTranslatef(-0.5f, -0.5f, -0.5f);
-
-    glColor4f(1.0f, 1.0f, 1.0f, 0.8f);
-    glDrawArrays(GL_QUADS, 0, 24);
-
-    if (xOffs[i] > 1.0f || xOffs[i] < -1.0f) {
-        xInc[i] = -xInc[i];
-        xOffs[i] = xOffs[i] > 1.0f ? 1.0f : -1.0f;
-    }
-    xOffs[i] += xInc[i];
-    yOffs[i] = qAbs(cos((-3.141592f * jmp) * xOffs[i]) * amp) - 1;
-    rot[i] += rotation;
-}
diff --git a/examples/opengl/framebufferobject2/glwidget.h b/examples/opengl/framebufferobject2/glwidget.h
deleted file mode 100644
index 2991a4fdf2..0000000000
--- a/examples/opengl/framebufferobject2/glwidget.h
+++ /dev/null
@@ -1,65 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2013 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 <QtOpenGL>
-
-class GLWidget : public QGLWidget
-{
-public:
-    GLWidget(QWidget *parent);
-    ~GLWidget();
-    void initializeGL() Q_DECL_OVERRIDE;
-    void resizeGL(int w, int h) Q_DECL_OVERRIDE;
-    void paintGL() Q_DECL_OVERRIDE;
-    void timerEvent(QTimerEvent *) Q_DECL_OVERRIDE { update(); }
-    void mousePressEvent(QMouseEvent *) Q_DECL_OVERRIDE { killTimer(timerId); }
-    void mouseReleaseEvent(QMouseEvent *) Q_DECL_OVERRIDE { timerId = startTimer(20); }
-
-    void drawCube(int i, GLfloat z, GLfloat ri, GLfloat jmp, GLfloat amp);
-
-private:
-    GLfloat rot[3], xOffs[3], yOffs[3], xInc[3];
-    GLuint pbufferList;
-    GLuint cubeTexture;
-    int timerId;
-
-    QGLFramebufferObject *fbo;
-};
-
diff --git a/examples/opengl/framebufferobject2/main.cpp b/examples/opengl/framebufferobject2/main.cpp
deleted file mode 100644
index 4c9aa9840f..0000000000
--- a/examples/opengl/framebufferobject2/main.cpp
+++ /dev/null
@@ -1,61 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
-** Contact: http://www.qt-project.org/legal
-**
-** This file is part of the examples of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
-**
-** "Redistribution and use in source and binary forms, with or without
-** modification, are permitted provided that the following conditions are
-** met:
-**   * Redistributions of source code must retain the above copyright
-**     notice, this list of conditions and the following disclaimer.
-**   * Redistributions in binary form must reproduce the above copyright
-**     notice, this list of conditions and the following disclaimer in
-**     the documentation and/or other materials provided with the
-**     distribution.
-**   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
-**     of its contributors may be used to endorse or promote products derived
-**     from this software without specific prior written permission.
-**
-**
-** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include <QtWidgets/QApplication>
-#include <QtWidgets/QMessageBox>
-#include "glwidget.h"
-
-int main(int argc, char **argv)
-{
-    Q_INIT_RESOURCE(framebufferobject2);
-
-    QApplication a(argc, argv);
-    if (!QGLFormat::hasOpenGL() || !QGLFramebufferObject::hasOpenGLFramebufferObjects()) {
-        QMessageBox::information(0, "OpenGL framebuffer objects 2",
-                                 "This system does not support OpenGL/framebuffer objects.");
-        return -1;
-    }
-
-    GLWidget widget(0);
-    widget.resize(640, 480);
-    widget.show();
-    return a.exec();
-}
-