Added loading of video node factories from plugins

This change will allow us to add new video node factories that
can be loaded dynamically at runtime.

The previous video node factories, I420 and RGB have been kept
as static parts of the Qt Multimedia imports, but can be moved
to plugins at a later date.

For plugins to be able to find and use QSGVideoNode, the class
has to be exported.

Change-Id: Idbead9a8ad33619cebe90fcec92eb29cf52ae9bd
Reviewed-by: Michael Goddard <michael.goddard@nokia.com>

src/qtmultimediaquicktools/qsgvideonode_p.cpp

@@ -0,0 +1,128 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/
+**
+** This file is part of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** 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 1.1, 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.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qsgvideonode_p.h"
+
+QT_BEGIN_NAMESPACE
+
+QSGVideoNode::QSGVideoNode()
+    : m_orientation(-1)
+{
+}
+
+/* Helpers */
+static inline void qSetGeom(QSGGeometry::TexturedPoint2D *v, const QPointF &p)
+{
+    v->x = p.x();
+    v->y = p.y();
+}
+
+static inline void qSetTex(QSGGeometry::TexturedPoint2D *v, const QPointF &p)
+{
+    v->tx = p.x();
+    v->ty = p.y();
+}
+
+/* Update the vertices and texture coordinates.  Orientation must be in {0,90,180,270} */
+void QSGVideoNode::setTexturedRectGeometry(const QRectF &rect, const QRectF &textureRect, int orientation)
+{
+    if (rect == m_rect && textureRect == m_textureRect && orientation == m_orientation)
+        return;
+
+    m_rect = rect;
+    m_textureRect = textureRect;
+    m_orientation = orientation;
+
+    QSGGeometry *g = geometry();
+
+    if (g == 0)
+        g = new QSGGeometry(QSGGeometry::defaultAttributes_TexturedPoint2D(), 4);
+
+    QSGGeometry::TexturedPoint2D *v = g->vertexDataAsTexturedPoint2D();
+
+    // Set geometry first
+    qSetGeom(v + 0, rect.topLeft());
+    qSetGeom(v + 1, rect.bottomLeft());
+    qSetGeom(v + 2, rect.topRight());
+    qSetGeom(v + 3, rect.bottomRight());
+
+    // and then texture coordinates
+    switch (orientation) {
+        default:
+            // tl, bl, tr, br
+            qSetTex(v + 0, textureRect.topLeft());
+            qSetTex(v + 1, textureRect.bottomLeft());
+            qSetTex(v + 2, textureRect.topRight());
+            qSetTex(v + 3, textureRect.bottomRight());
+            break;
+
+        case 90:
+            // tr, tl, br, bl
+            qSetTex(v + 0, textureRect.topRight());
+            qSetTex(v + 1, textureRect.topLeft());
+            qSetTex(v + 2, textureRect.bottomRight());
+            qSetTex(v + 3, textureRect.bottomLeft());
+            break;
+
+        case 180:
+            // br, tr, bl, tl
+            qSetTex(v + 0, textureRect.bottomRight());
+            qSetTex(v + 1, textureRect.topRight());
+            qSetTex(v + 2, textureRect.bottomLeft());
+            qSetTex(v + 3, textureRect.topLeft());
+            break;
+
+        case 270:
+            // bl, br, tl, tr
+            qSetTex(v + 0, textureRect.bottomLeft());
+            qSetTex(v + 1, textureRect.bottomRight());
+            qSetTex(v + 2, textureRect.topLeft());
+            qSetTex(v + 3, textureRect.topRight());
+            break;
+    }
+
+    if (!geometry())
+        setGeometry(g);
+
+    markDirty(DirtyGeometry);
+}
+
+QT_END_NAMESPACE

src/qtmultimediaquicktools/qtmultimediaquicktools.pro

@@ -0,0 +1,30 @@
+load(qt_module)
+
+TEMPLATE = lib
+
+TARGET = QtMultimediaQuick_p
+QPRO_PWD = $$PWD
+QT = core quick multimedia-private
+
+!static:DEFINES += QT_MAKEDLL
+
+DEFINES += QT_BUILD_QTMM_QUICK_LIB
+
+# Header files must go inside source directory of a module
+# to be installed by syncqt.
+INCLUDEPATH += ../multimedia/qtmultimediaquicktools_headers/
+DEPENDPATH += ../multimedia/qtmultimediaquicktools_headers/
+
+PRIVATE_HEADERS += \
+    qsgvideonode_p.h \
+    qtmultimediaquickdefs_p.h
+
+SOURCES += \
+    qsgvideonode_p.cpp
+
+HEADERS += $$PRIVATE_HEADERS
+
+DESTDIR = $$QT.multimedia.libs
+target.path = $$[QT_INSTALL_LIBS]
+
+INSTALLS += target