examples/openvg/star/starwidget.cpp
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/openvg/star/starwidget.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,115 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** 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 Technology Preview License Agreement accompanying
+** this package.
+**
+** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#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.beginNativePainting();
+
+    // 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.endNativePainting();
+
+    painter.end();
+}