Add the "star" example, which demonstrates how to mix OpenVG and QPainter

Reviewed-by: trustme

6 files changed, 289 insertions, 0 deletions

diff --git a/examples/openvg/README b/examples/openvg/README
new file mode 100644
index 0000000..5e385ea
--- /dev/null
+++ b/examples/openvg/README
@@ -0,0 +1,40 @@
+Qt provides support for integration with OpenVG implementations on
+platforms with appropriate hardware acceleration.
+
+These examples demonstrate the basic techniques used to take advantage of
+OpenVG in Qt applications.  In particular, the "star" example shows how
+to mix QPainter and OpenVG calls in the same paint event.
+
+The example launcher provided with Qt can be used to explore each of the
+examples in this directory.
+
+Documentation for these examples can be found via the Tutorial and Examples
+link in the main Qt documentation.
+
+
+Finding the Qt Examples and Demos launcher
+==========================================
+
+On Windows:
+
+The launcher can be accessed via the Windows Start menu. Select the menu
+entry entitled "Qt Examples and Demos" entry in the submenu containing
+the Qt tools.
+
+On Mac OS X:
+
+For the binary distribution, the qtdemo executable is installed in the
+/Developer/Applications/Qt directory. For the source distribution, it is
+installed alongside the other Qt tools on the path specified when Qt is
+configured.
+
+On Unix/Linux:
+
+The qtdemo executable is installed alongside the other Qt tools on the path
+specified when Qt is configured.
+
+On all platforms:
+
+The source code for the launcher can be found in the demos/qtdemo directory
+in the Qt package. This example is built at the same time as the Qt libraries,
+tools, examples, and demonstrations.
diff --git a/examples/openvg/openvg.pro b/examples/openvg/openvg.pro
new file mode 100644
index 0000000..d76a389
--- /dev/null
+++ b/examples/openvg/openvg.pro
@@ -0,0 +1,8 @@
+TEMPLATE      = subdirs
+SUBDIRS       = star
+
+# install
+target.path = $$[QT_INSTALL_EXAMPLES]/openvg
+sources.files = $$SOURCES $$HEADERS $$RESOURCES $$FORMS openvg.pro README
+sources.path = $$[QT_INSTALL_EXAMPLES]/openvg
+INSTALLS += target sources
diff --git a/examples/openvg/star/main.cpp b/examples/openvg/star/main.cpp
new file mode 100644
index 0000000..eec2186
--- /dev/null
+++ b/examples/openvg/star/main.cpp
@@ -0,0 +1,54 @@
+/****************************************************************************
+**
+** 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://www.qtsoftware.com/contact.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QApplication>
+#include "starwidget.h"
+
+int main(int argc, char *argv[])
+{
+#ifdef Q_OS_SYMBIAN
+    QApplication::setGraphicsSystem("openvg");
+#endif
+    QApplication app(argc, argv);
+    StarWidget mw;
+    mw.show();
+    return app.exec();
+}
diff --git a/examples/openvg/star/star.pro b/examples/openvg/star/star.pro
new file mode 100644
index 0000000..90c236d
--- /dev/null
+++ b/examples/openvg/star/star.pro
@@ -0,0 +1,6 @@
+TEMPLATE = app
+TARGET = star
+CONFIG += qt debug warn_on
+QT += openvg
+SOURCES = starwidget.cpp main.cpp
+HEADERS = starwidget.h
diff --git a/examples/openvg/star/starwidget.cpp b/examples/openvg/star/starwidget.cpp
new file mode 100644
index 0000000..9d2a255
--- /dev/null
+++ b/examples/openvg/star/starwidget.cpp
@@ -0,0 +1,115 @@
+/****************************************************************************
+**
+** 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://www.qtsoftware.com/contact.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "starwidget.h"
+
+StarWidget::StarWidget(QWidget *parent)
+    : QWidget(parent)
+    , path(VG_INVALID_HANDLE)
+    , pen(Qt::red, 4.0, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin)
+    , brush(Qt::yellow)
+{
+    setMinimumSize(220, 250);
+    setSizePolicy(QSizePolicy::MinimumExpanding, QSizePolicy::MinimumExpanding);
+}
+
+static VGubyte const starSegments[] = {
+    VG_MOVE_TO_ABS,
+    VG_LINE_TO_REL,
+    VG_LINE_TO_REL,
+    VG_LINE_TO_REL,
+    VG_LINE_TO_REL,
+    VG_CLOSE_PATH
+};
+static VGfloat const starCoords[] = {
+    110, 35,
+    50, 160,
+    -130, -100,
+    160, 0,
+    -130, 100
+};
+
+void StarWidget::paintEvent(QPaintEvent *)
+{
+    QPainter painter;
+    painter.begin(this);
+
+    // Make sure that we are using the OpenVG paint engine.
+    if (painter.paintEngine()->type() != QPaintEngine::OpenVG) {
+#ifdef Q_WS_QWS
+        qWarning("Not using OpenVG: use the '-display' option to specify an OpenVG driver");
+#else
+        qWarning("Not using OpenVG: specify '-graphicssystem OpenVG'");
+#endif
+        return;
+    }
+
+    // Select a pen and a brush for drawing the star.
+    painter.setPen(pen);
+    painter.setBrush(brush);
+
+    // We want the star border to be anti-aliased.
+    painter.setRenderHints(QPainter::Antialiasing);
+
+    // Flush the state changes to the OpenVG implementation
+    // and prepare to perform raw OpenVG calls.
+    painter.paintEngine()->syncState();
+
+    // Cache the path if we haven't already.
+    if (path == VG_INVALID_HANDLE) {
+        path = vgCreatePath(VG_PATH_FORMAT_STANDARD,
+                            VG_PATH_DATATYPE_F,
+                            1.0f, // scale
+                            0.0f, // bias
+                            6,    // segmentCapacityHint
+                            10,   // coordCapacityHint
+                            VG_PATH_CAPABILITY_ALL);
+        vgAppendPathData(path, sizeof(starSegments), starSegments, starCoords);
+    }
+
+    // Draw the star directly using the OpenVG API.
+    vgDrawPath(path, VG_FILL_PATH | VG_STROKE_PATH);
+
+    // Restore normal QPainter operations.
+    painter.paintEngine()->syncState();
+
+    painter.end();
+}
diff --git a/examples/openvg/star/starwidget.h b/examples/openvg/star/starwidget.h
new file mode 100644
index 0000000..883f8c4
--- /dev/null
+++ b/examples/openvg/star/starwidget.h
@@ -0,0 +1,66 @@
+/****************************************************************************
+**
+** 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://www.qtsoftware.com/contact.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef STARWIDGET_H
+#define STARWIDGET_H
+
+#include <QWidget>
+#include <QPainter>
+#include <QPaintEngine>
+#include "qvg.h"
+
+class StarWidget : public QWidget
+{
+    Q_OBJECT
+public:
+    StarWidget(QWidget *parent = 0);
+    ~StarWidget() {}
+
+protected:
+    void paintEvent(QPaintEvent *);
+
+private:
+    VGPath path;
+    QPen pen;
+    QBrush brush;
+};
+
+#endif