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, 168 insertions, 0 deletions

diff --git a/src/opengl/qglpaintdevice_p.h b/src/opengl/qglpaintdevice_p.h
new file mode 100644
index 0000000..ad680a9
--- /dev/null
+++ b/src/opengl/qglpaintdevice_p.h
@@ -0,0 +1,168 @@
+/****************************************************************************
+**
+** 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.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QGLPAINTDEVICE_P_H
+#define QGLPAINTDEVICE_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists for the convenience
+// of the QtOpenGL module.  This header file may change from
+// version to version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <qpaintdevice.h>
+#include <qgl.h>
+
+class QGLPaintDevice : public QPaintDevice
+{
+public:
+    QGLPaintDevice();
+    virtual ~QGLPaintDevice();
+
+    virtual void beginPaint();
+    virtual void endPaint();
+
+    virtual QColor backgroundColor() const;
+    virtual bool autoFillBackground() const;
+    virtual bool hasTransparentBackground() const;
+
+    // inline these?
+    QGLContext* context() const;
+    QGLFormat format() const;
+    virtual QSize size() const;
+
+    // returns the QGLPaintDevice for the given QPaintDevice
+    static QGLPaintDevice* getDevice(QPaintDevice*);
+
+protected:
+    // Inline?
+    void setContext(QGLContext* c);
+
+private:
+    QGLContext* m_context;
+};
+
+
+// Wraps a QGLWidget
+class QGLWidget;
+class QGLWidgetGLPaintDevice : public QGLPaintDevice
+{
+public:
+    QGLWidgetGLPaintDevice();
+
+    virtual QPaintEngine* paintEngine() const;
+
+    virtual QColor backgroundColor() const;
+    virtual bool autoFillBackground() const;
+    virtual bool hasTransparentBackground() const;
+
+    // QGLWidgets need to do swapBufers in endPaint:
+    virtual void endPaint();
+    virtual QSize size() const;
+
+    void setWidget(QGLWidget*);
+
+private:
+    friend class QGLWidget;
+    QGLWidget *glWidget;
+};
+
+
+
+/*
+Replaces:
+
+class QGLPixelBuffer;
+class QGLFramebufferObject;
+class QWSGLWindowSurface;
+class QGLWindowSurface;
+class QGLPixmapData;
+class QGLDrawable {
+public:
+    QGLDrawable() : widget(0), buffer(0), fbo(0)
+#if defined(Q_WS_QWS) || (!defined(QT_OPENGL_ES_1) && !defined(QT_OPENGL_ES_1_CL))
+                  , wsurf(0)
+#endif
+#if !defined(QT_OPENGL_ES_1) && !defined(QT_OPENGL_ES_1_CL)
+                  , pixmapData(0)
+#endif
+        {}
+    void setDevice(QPaintDevice *pdev);
+    void swapBuffers();
+    void makeCurrent();
+    void doneCurrent();
+    QSize size() const;
+    QGLFormat format() const;
+    GLuint bindTexture(const QImage &image, GLenum target = GL_TEXTURE_2D, GLint format = GL_RGBA);
+    GLuint bindTexture(const QPixmap &pixmap, GLenum target = GL_TEXTURE_2D, GLint format = GL_RGBA);
+    QColor backgroundColor() const;
+    QGLContext *context() const;
+    bool autoFillBackground() const;
+    bool hasTransparentBackground() const;
+
+#if !defined(QT_OPENGL_ES_1) && !defined(QT_OPENGL_ES_1_CL)
+    QGLPixmapData *copyOnBegin() const;
+#endif
+
+private:
+    bool wasBound;
+    QGLWidget *widget;
+    QGLPixelBuffer *buffer;
+    QGLFramebufferObject *fbo;
+#ifdef Q_WS_QWS
+    QWSGLWindowSurface *wsurf;
+#elif !defined(QT_OPENGL_ES_1) && !defined(QT_OPENGL_ES_1_CL)
+    QGLWindowSurface *wsurf;
+#endif
+
+#if !defined(QT_OPENGL_ES_1) && !defined(QT_OPENGL_ES_1_CL)
+    QGLPixmapData *pixmapData;
+#endif
+    int previous_fbo;
+};
+*/
+
+#endif // QGLPAINTDEVICE_P_H