Use one render loop per QQuickWindow

See the task for the full reasoning behind this patch.

The threaded renderloop has been refactored to have one window per
thread. This is mostly a simplification of the current code path where
for loops over multiple windows are turned into if (window).

The QSGContext has been split into two classes, QSGRenderContext
for which there is one per OpenGLContext.

The rest of the patch is name changes and a couple of cleanups
in the hopes of simplifying this change.

Task-number: QTBUG-33993

Change-Id: I31c81f9694d7da7474a72333169be38de62613c4
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

8 files changed, 443 insertions, 0 deletions

diff --git a/tests/auto/quick/scenegraph/data/logo-big.jpg b/tests/auto/quick/scenegraph/data/logo-big.jpg
new file mode 100644
index 0000000000..1be71d9945
--- /dev/null
+++ b/tests/auto/quick/scenegraph/data/logo-big.jpg
diff --git a/tests/auto/quick/scenegraph/data/logo-small.jpg b/tests/auto/quick/scenegraph/data/logo-small.jpg
new file mode 100644
index 0000000000..f11a5dfc6b
--- /dev/null
+++ b/tests/auto/quick/scenegraph/data/logo-small.jpg
diff --git a/tests/auto/quick/scenegraph/data/manyWindows_dftext.qml b/tests/auto/quick/scenegraph/data/manyWindows_dftext.qml
new file mode 100644
index 0000000000..69d235d021
--- /dev/null
+++ b/tests/auto/quick/scenegraph/data/manyWindows_dftext.qml
@@ -0,0 +1,50 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** 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, Digia gives you certain additional
+** rights.  These rights are described in the Digia 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.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.2
+
+Text
+{
+    width: 100
+    height: 100
+    text: "abcdefghijklmnopqrstuwABCDEFGHIJKLMNOPPQRSTUWXYZ1234567890!@#$%^&*()_"
+    wrapMode: Text.WrapAnywhere
+}
diff --git a/tests/auto/quick/scenegraph/data/manyWindows_image.qml b/tests/auto/quick/scenegraph/data/manyWindows_image.qml
new file mode 100644
index 0000000000..1b356110ed
--- /dev/null
+++ b/tests/auto/quick/scenegraph/data/manyWindows_image.qml
@@ -0,0 +1,52 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** 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, Digia gives you certain additional
+** rights.  These rights are described in the Digia 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.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.2
+
+Image {
+    width: 100
+    height: 100
+    source: "logo-big.jpg"
+    Image {
+        anchors.centerIn: parent
+        source: "logo-small.jpg"
+    }
+}
diff --git a/tests/auto/quick/scenegraph/data/manyWindows_ntext.qml b/tests/auto/quick/scenegraph/data/manyWindows_ntext.qml
new file mode 100644
index 0000000000..ebd06e360b
--- /dev/null
+++ b/tests/auto/quick/scenegraph/data/manyWindows_ntext.qml
@@ -0,0 +1,51 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** 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, Digia gives you certain additional
+** rights.  These rights are described in the Digia 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.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.2
+
+Text
+{
+    width: 100
+    height: 100
+    text: "abcdefghijklmnopqrstuwABCDEFGHIJKLMNOPPQRSTUWXYZ1234567890!@#$%^&*()_"
+    wrapMode: Text.WrapAnywhere
+    renderType: Text.NativeRendering
+}
diff --git a/tests/auto/quick/scenegraph/data/manyWindows_rects.qml b/tests/auto/quick/scenegraph/data/manyWindows_rects.qml
new file mode 100644
index 0000000000..984968985a
--- /dev/null
+++ b/tests/auto/quick/scenegraph/data/manyWindows_rects.qml
@@ -0,0 +1,70 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** 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, Digia gives you certain additional
+** rights.  These rights are described in the Digia 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.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.2
+
+Rectangle {
+    width: 100
+    height: 100
+
+    gradient: Gradient {
+        GradientStop { position: 0; color: "black" }
+        GradientStop { position: 1; color: "red" }
+    }
+
+    Rectangle {
+        width: 40
+        height: 40
+        rotation: 30
+        color: "#00ff00";
+        antialiasing: true
+        x: parent.width / 3 - width / 2
+        y: parent.height / 3 - height/ 2
+    }
+    Rectangle {
+        width: 40
+        height: 40
+        rotation: 30
+        color: "blue"
+        x: parent.width * 2 / 3 - width / 2
+        y: parent.height * 2 / 3 - height/ 2
+    }
+}
diff --git a/tests/auto/quick/scenegraph/scenegraph.pro b/tests/auto/quick/scenegraph/scenegraph.pro
new file mode 100644
index 0000000000..7e7a8eb162
--- /dev/null
+++ b/tests/auto/quick/scenegraph/scenegraph.pro
@@ -0,0 +1,11 @@
+CONFIG += testcase
+TARGET = tst_scenegraph
+SOURCES += tst_scenegraph.cpp
+
+include (../../shared/util.pri)
+
+macx:CONFIG -= app_bundle
+
+QT += core-private gui-private qml-private quick-private  testlib
+
+DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0
diff --git a/tests/auto/quick/scenegraph/tst_scenegraph.cpp b/tests/auto/quick/scenegraph/tst_scenegraph.cpp
new file mode 100644
index 0000000000..cfa491ce97
--- /dev/null
+++ b/tests/auto/quick/scenegraph/tst_scenegraph.cpp
@@ -0,0 +1,209 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** 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, Digia gives you certain additional
+** rights.  These rights are described in the Digia 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.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <qtest.h>
+
+#include <QtQuick>
+#include <private/qquickanimator_p.h>
+
+
+
+#include <QtQml>
+
+class tst_SceneGraph : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void manyWindows_data();
+    void manyWindows();
+
+};
+
+template <typename T> class ScopedList : public QList<T> {
+public:
+    ~ScopedList() { qDeleteAll(*this); }
+};
+
+QQuickView *createView(const QString &file, QWindow *parent = 0, int x = -1, int y = -1, int w = -1, int h = -1)
+{
+    QQuickView *view = new QQuickView(parent);
+    view->setSource(QUrl::fromLocalFile("data/" + file));
+    if (x >= 0 && y >= 0) view->setPosition(x, y);
+    if (w >= 0 && h >= 0) view->resize(w, h);
+    view->show();
+    return view;
+}
+
+QImage showAndGrab(const QString &file, int w, int h)
+{
+    QQuickView view;
+    view.setSource(QUrl::fromLocalFile(QStringLiteral("data/") + file));
+    if (w >= 0 && h >= 0)
+        view.resize(w, h);
+    view.create();
+    return view.grabWindow();
+}
+
+// Assumes the images are opaque white...
+bool containsSomethingOtherThanWhite(const QImage &image)
+{
+    Q_ASSERT(image.format() == QImage::Format_ARGB32_Premultiplied
+             || image.format() == QImage::Format_RGB32);
+    int w = image.width();
+    int h = image.height();
+    for (int y=0; y<h; ++y) {
+        const uint *pixels = (const uint *) image.constScanLine(y);
+        for (int x=0; x<w; ++x)
+            if (pixels[x] != 0xffffffff)
+                return true;
+    }
+    return false;
+}
+
+// To compare images, we need a special function with a bit of error
+// as glyphs has an invisible, but measurable variance depending
+// on where in the glyph cache they end up.
+bool compareImages(const QImage &ia, const QImage &ib)
+{
+    if (ia.size() != ib.size())
+        qDebug() << "images are of different size" << ia.size() << ib.size();
+    Q_ASSERT(ia.size() == ib.size());
+    Q_ASSERT(ia.format() == ib.format());
+
+    int w = ia.width();
+    int h = ia.height();
+    const int tolerance = 1;
+    for (int y=0; y<h; ++y) {
+        const uint *as= (const uint *) ia.constScanLine(y);
+        const uint *bs= (const uint *) ib.constScanLine(y);
+        for (int x=0; x<w; ++x) {
+            uint a = as[x];
+            uint b = bs[x];
+
+            // No tolerance for error in the alpha.
+            if ((a & 0xff000000) != (b & 0xff000000))
+                return false;
+            if (qAbs(qRed(a) - qRed(b)) > tolerance)
+                return false;
+            if (qAbs(qRed(a) - qRed(b)) > tolerance)
+                return false;
+            if (qAbs(qRed(a) - qRed(b)) > tolerance)
+                return false;
+        }
+    }
+    return true;
+}
+
+void tst_SceneGraph::manyWindows_data()
+{
+    QTest::addColumn<QString>("file");
+    QTest::addColumn<bool>("toplevel");
+
+    QTest::newRow("image,toplevel") << QStringLiteral("manyWindows_image.qml") << true;
+    QTest::newRow("image,subwindow") << QStringLiteral("manyWindows_image.qml") << false;
+    QTest::newRow("dftext,toplevel") << QStringLiteral("manyWindows_dftext.qml") << true;
+    QTest::newRow("dftext,subwindow") << QStringLiteral("manyWindows_dftext.qml") << false;
+    QTest::newRow("ntext,toplevel") << QStringLiteral("manyWindows_ntext.qml") << true;
+    QTest::newRow("ntext,subwindow") << QStringLiteral("manyWindows_ntext.qml") << false;
+    QTest::newRow("rects,toplevel") << QStringLiteral("manyWindows_rects.qml") << true;
+    QTest::newRow("rects,subwindow") << QStringLiteral("manyWindows_rects.qml") << false;
+}
+
+void tst_SceneGraph::manyWindows()
+{
+    QFETCH(QString, file);
+    QFETCH(bool, toplevel);
+
+    QScopedPointer<QWindow> parent;
+    if (!toplevel) {
+        parent.reset(new QWindow());
+        parent->resize(200, 200);
+        parent->show();
+    }
+
+    ScopedList <QQuickView *> views;
+
+    const int COUNT = 4;
+
+    QImage baseLine;
+    for (int i=0; i<COUNT; ++i) {
+        views << createView(file, parent.data(), (i % 2) * 100, (i / 2) * 100, 100, 100);
+    }
+    for (int i=0; i<COUNT; ++i) {
+        QQuickView *view = views.at(i);
+        QTest::qWaitForWindowExposed(view);
+        QImage content = view->grabWindow();
+        if (i == 0) {
+            baseLine = content;
+            QVERIFY(containsSomethingOtherThanWhite(baseLine));
+        } else {
+            QVERIFY(compareImages(content, baseLine));
+        }
+    }
+
+    // Wipe and recreate one (scope pointer delets it...)
+    delete views.takeLast();
+    QQuickView *last = createView(file, parent.data(), 100, 100, 100, 100);
+    QTest::qWaitForWindowExposed(last);
+    views << last;
+    QVERIFY(compareImages(baseLine, last->grabWindow()));
+
+    // Wipe and recreate all
+    qDeleteAll(views);
+    views.clear();
+
+    for (int i=0; i<COUNT; ++i) {
+        views << createView(file, parent.data(), (i % 2) * 100, (i / 2) * 100, 100, 100);
+    }
+    for (int i=0; i<COUNT; ++i) {
+        QQuickView *view = views.at(i);
+        QTest::qWaitForWindowExposed(view);
+        QImage content = view->grabWindow();
+        QVERIFY(compareImages(content, baseLine));
+    }
+}
+
+
+#include "tst_scenegraph.moc"
+
+QTEST_MAIN(tst_SceneGraph)
+