Qt Reference Documentation

# CurtainEffect.qml Example File

declarative/shadereffects/qml/CurtainEffect.qml

     /****************************************************************************
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     ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
     ** All rights reserved.
     ** Contact: Nokia Corporation (qt-info@nokia.com)
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     ** This file is part of the examples of the Qt Toolkit.
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     ** $QT_BEGIN_LICENSE:LGPL$
     ** GNU Lesser General Public License Usage
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     ** rights. These rights are described in the Nokia Qt LGPL Exception
     ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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     ** GNU General Public License Usage
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     ** Public License version 3.0 as published by the Free Software Foundation
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     import QtQuick 1.0
     import Qt.labs.shaders 1.0

     ShaderEffectItem {
         anchors.fill: parent
         property variant source
         meshResolution: Qt.size(50, 50)

         property real topWidth: width / 2
         property real bottomWidth: width / 2
         property real originalWidth: width
         property real originalHeight: height
         property real amplitude: 0.1

         vertexShader: "
             attribute highp vec4 qt_Vertex;
             attribute highp vec2 qt_MultiTexCoord0;
             uniform highp mat4 qt_ModelViewProjectionMatrix;
             varying highp vec2 qt_TexCoord0;
             varying lowp float shade;

             uniform highp float topWidth;
             uniform highp float bottomWidth;
             uniform highp float originalWidth;
             uniform highp float originalHeight;
             uniform highp float amplitude;

             void main() {
                 qt_TexCoord0 = qt_MultiTexCoord0;

                 highp vec4 shift = vec4(0, 0, 0, 0);
                 shift.x = qt_Vertex.x * ((originalWidth - topWidth) + (topWidth - bottomWidth) * (qt_Vertex.y / originalHeight)) / originalWidth;

                 shade = sin(21.9911486 * qt_Vertex.x / originalWidth);
                 shift.y = amplitude * (originalWidth - topWidth + (topWidth - bottomWidth) * (qt_Vertex.y / originalHeight)) * shade;

                 gl_Position = qt_ModelViewProjectionMatrix * (qt_Vertex - shift);

                 shade = 0.2 * (2.0 - shade ) * (1.0 - (bottomWidth + (topWidth  - bottomWidth) * (1.0 - qt_Vertex.y / originalHeight)) / originalWidth);
             }
         "

         fragmentShader: "
             uniform sampler2D source;
             varying highp vec2 qt_TexCoord0;
             varying lowp float shade;
             void main() {
                 highp vec4 color = texture2D(source, qt_TexCoord0);
                 color.rgb *= 1.0 - shade;
                 gl_FragColor = color;
             }
         "
     }