1 files changed, 93 insertions, 0 deletions
diff --git a/src/declarative/particles/qsgtargeteddirection.cpp b/src/declarative/particles/qsgtargeteddirection.cpp
new file mode 100644
index 0000000000..9f1a868512
--- /dev/null
+++ b/src/declarative/particles/qsgtargeteddirection.cpp
@@ -0,0 +1,93 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the Declarative 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 "qsgtargeteddirection_p.h"
+#include "qsgparticleemitter_p.h"
+#include <cmath>
+#include <QDebug>
+
+QT_BEGIN_NAMESPACE
+QSGTargetedDirection::QSGTargetedDirection(QObject *parent) :
+    QSGStochasticDirection(parent)
+  , m_targetX(0)
+  , m_targetY(0)
+  , m_targetVariation(0)
+  , m_proportionalMagnitude(false)
+  , m_magnitude(0)
+  , m_magnitudeVariation(0)
+  , m_targetItem(0)
+{
+}
+
+const QPointF &QSGTargetedDirection::sample(const QPointF &from)
+{
+    //###This approach loses interpolating the last position of the target (like we could with the emitter) is it worthwhile?
+    qreal targetX;
+    qreal targetY;
+    if(m_targetItem){
+        QSGParticleEmitter* parentEmitter = qobject_cast<QSGParticleEmitter*>(parent());
+        targetX = m_targetItem->width()/2;
+        targetY = m_targetItem->height()/2;
+        if(!parentEmitter){
+            qWarning() << "Directed vector is not a child of the emitter. Mapping of target item coordinates may fail.";
+            targetX += m_targetItem->x();
+            targetY += m_targetItem->y();
+        }else{
+            m_ret = parentEmitter->mapFromItem(m_targetItem, QPointF(targetX, targetY));
+            targetX = m_ret.x();
+            targetY = m_ret.y();
+        }
+    }else{
+        targetX = m_targetX;
+        targetY = m_targetY;
+    }
+    targetX += 0 - from.x() - m_targetVariation + rand()/(float)RAND_MAX * m_targetVariation*2;
+    targetY += 0 - from.y() - m_targetVariation + rand()/(float)RAND_MAX * m_targetVariation*2;
+    qreal theta = atan2(targetY, targetX);
+    qreal mag = m_magnitude + rand()/(float)RAND_MAX * m_magnitudeVariation * 2 - m_magnitudeVariation;
+    if(m_proportionalMagnitude)
+        mag *= sqrt(targetX * targetX + targetY * targetY);
+    m_ret.setX(mag * cos(theta));
+    m_ret.setY(mag * sin(theta));
+    return m_ret;
+}
+
+QT_END_NAMESPACE