EffectMagnify.qml Example File

 /****************************************************************************
 **
 ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
 ** Contact: http://www.qt-project.org/legal
 **
 ** This file is part of the Qt Mobility Components.
 **
 ** $QT_BEGIN_LICENSE:LGPL$
 ** 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 1.0

 Effect {
     id: root
     divider: false
     parameters: ListModel {
         ListElement {
             name: "radius"
             value: 0.5
         }
         ListElement {
             name: "diffraction"
             value: 0.5
         }
     }

     property real posX: -1
     property real posY: -1

     QtObject {
         id: d
         property real oldTargetWidth: root.targetWidth
         property real oldTargetHeight: root.targetHeight
     }

     // Transform slider values, and bind result to shader uniforms
     property real radius: parameters.get(0).value * 100
     property real diffractionIndex: parameters.get(1).value

     onTargetWidthChanged: {
         if (posX == -1)
             posX = targetWidth / 2
         else if (d.oldTargetWidth != 0)
             posX *= (targetWidth / d.oldTargetWidth)
         d.oldTargetWidth = targetWidth
     }

     onTargetHeightChanged: {
         if (posY == -1)
             posY = targetHeight / 2
         else if (d.oldTargetHeight != 0)
             posY *= (targetHeight / d.oldTargetHeight)
         d.oldTargetHeight = targetHeight
     }

     fragmentShaderFilename: "shaders/magnify.fsh"

     MouseArea {
         anchors.fill: parent
         onPositionChanged: { root.posX = mouse.x; root.posY = root.targetHeight - mouse.y }
     }
 }