EffectMagnify.qml Example File

  /****************************************************************************
  **
  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the Qt Mobility Components.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** 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 The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** BSD License Usage
  ** Alternatively, you may use this file under the terms of the BSD license
  ** as follows:
  **
  ** "Redistribution and use in source and binary forms, with or without
  ** modification, are permitted provided that the following conditions are
  ** met:
  **   * Redistributions of source code must retain the above copyright
  **     notice, this list of conditions and the following disclaimer.
  **   * Redistributions in binary form must reproduce the above copyright
  **     notice, this list of conditions and the following disclaimer in
  **     the documentation and/or other materials provided with the
  **     distribution.
  **   * Neither the name of The Qt Company Ltd nor the names of its
  **     contributors may be used to endorse or promote products derived
  **     from this software without specific prior written permission.
  **
  **
  ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/

  import QtQuick 2.1
  import QtQuick.Window 2.1

  Effect {
      id: root
      divider: false
      parameters: ListModel {
          ListElement {
              name: "Radius"
              value: 0.5
          }
          ListElement {
              name: "Diffraction"
              value: 0.5
          }
          onDataChanged: updateParameters()
      }

      function updateParameters()
      {
          radius   = parameters.get(0).value * 100;
          diffractionIndex = parameters.get(1).value;
      }

      property real posX: -1
      property real posY: -1
      property real pixDens: Screen.pixelDensity

      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: 0.5 * 100
      property real diffractionIndex: 0.5

      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: "magnify.fsh"

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