Replace QGLDrawable with a new QGLPaintDevice

This patch adds a new abstract base class which inherits from
QPaintDevice called QGLPaintDevice. This base class will contain
everything the GL paint engines need to know about the surface they are
drawing onto. As such, new surfaces can be targeted by the GL paint
engines without having to modify QtOpenGL. This is very useful for
plugins, specifically QGraphicsSystem plugins.

To unify things a little, the GL paint engines will use the same
QGLPaintDevice API to render into existing target surfaces (QGLWidget,
QGLPixelBuffer & QGLFrameBufferObject). Ideally we'd make QGLPaintDevice
a common ancestor for these surfaces, but obviously that wil break B/C.

This patch only implements QGLWidget using the new interface. Rendering
to other surfaces will be fixed in following patches.

1 files changed, 192 insertions, 0 deletions

diff --git a/src/opengl/qglpaintdevice.cpp b/src/opengl/qglpaintdevice.cpp
new file mode 100644
index 0000000..f7bd2a3
--- /dev/null
+++ b/src/opengl/qglpaintdevice.cpp
@@ -0,0 +1,192 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtOpenGL module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain
+** additional rights. These rights are described in the Nokia Qt LGPL
+** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
+** package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at http://qt.nokia.com/contact.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <private/qglpaintdevice_p.h>
+#include <private/qgl_p.h>
+
+QGLPaintDevice::QGLPaintDevice()
+    : m_context(0)
+{
+}
+
+QGLPaintDevice::~QGLPaintDevice()
+{
+}
+
+//extern QPaintEngine* qt_gl_engine(); // in qgl.cpp
+//extern QPaintEngine* qt_gl_2_engine(); // in qgl.cpp
+
+//inline bool qt_gl_preferGL2Engine()
+//{
+//#if defined(QT_OPENGL_ES_2)
+//    return true;
+//#else
+//    return (QGLFormat::openGLVersionFlags() & QGLFormat::OpenGL_Version_2_0)
+//           && qgetenv("QT_GL_USE_OPENGL1ENGINE").isEmpty();
+//#endif
+//}
+
+//QPaintEngine* QGLPaintDevice::paintEngine() const
+//{
+//#if defined(QT_OPENGL_ES_1) || defined(QT_OPENGL_ES_1_CL)
+//    return qt_gl_engine();
+//#elif defined(QT_OPENGL_ES_2)
+//    return qt_gl_2_engine();
+//#else
+//    if (!qt_gl_preferGL2Engine())
+//        return qt_gl_engine();
+//    else
+//        return qt_gl_2_engine();
+//#endif
+//}
+
+void QGLPaintDevice::beginPaint()
+{
+    m_context->makeCurrent();
+}
+
+void QGLPaintDevice::endPaint()
+{
+}
+
+QColor QGLPaintDevice::backgroundColor() const
+{
+    return QColor();
+}
+
+bool QGLPaintDevice::autoFillBackground() const
+{
+    return false;
+}
+
+bool QGLPaintDevice::hasTransparentBackground() const
+{
+    return false;
+}
+
+QGLContext* QGLPaintDevice::context() const
+{
+    return m_context;
+}
+
+QGLFormat QGLPaintDevice::format() const
+{
+    return m_context->format();
+}
+
+QSize QGLPaintDevice::size() const
+{
+    return QSize();
+}
+
+void QGLPaintDevice::setContext(QGLContext* c)
+{
+    m_context = c;
+}
+
+
+
+QGLWidgetGLPaintDevice::QGLWidgetGLPaintDevice()
+{
+}
+
+QPaintEngine* QGLWidgetGLPaintDevice::paintEngine() const
+{
+    return glWidget->paintEngine();
+}
+
+QColor QGLWidgetGLPaintDevice::backgroundColor() const
+{
+    return glWidget->palette().brush(glWidget->backgroundRole()).color();
+}
+
+bool QGLWidgetGLPaintDevice::autoFillBackground() const
+{
+    return glWidget->autoFillBackground();
+}
+
+bool QGLWidgetGLPaintDevice::hasTransparentBackground() const
+{
+    return glWidget->testAttribute(Qt::WA_TranslucentBackground);
+}
+
+void QGLWidgetGLPaintDevice::setWidget(QGLWidget* w)
+{
+    glWidget = w;
+}
+
+//void QGLWidgetGLPaintDevice::beginPaint()
+//{
+//    glWidget->makeCurrent();
+//}
+
+void QGLWidgetGLPaintDevice::endPaint()
+{
+    if (glWidget->autoBufferSwap())
+        glWidget->swapBuffers();
+}
+
+
+QSize QGLWidgetGLPaintDevice::size() const
+{
+    return glWidget->size();
+}
+
+// returns the QGLPaintDevice for the given QPaintDevice
+QGLPaintDevice* QGLPaintDevice::getDevice(QPaintDevice* pd)
+{
+    QGLPaintDevice* glpd = 0;
+
+    switch(pd->devType()) {
+        case QInternal::Widget:
+            // Should not be called on a non-gl widget:
+            Q_ASSERT(qobject_cast<QGLWidget*>(static_cast<QWidget*>(pd)));
+            glpd = &(static_cast<QGLWidget*>(pd)->d_func()->glDevice);
+            break;
+        default:
+            qWarning("QGLPaintDevice::getDevice() - Unknown device type %d", pd->devType());
+            break;
+    }
+
+    return glpd;
+}
+
+