- Qt 5.5
- Qt Quick
- Qt Quick Particles Examples - Emitters
- customemitter.qml Example File
- Qt 5.5.1 Reference Documentation

# customemitter.qml Example File

particles/emitters/content/customemitter.qml

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
    ** 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.
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    **     notice, this list of conditions and the following disclaimer in
    **     the documentation and/or other materials provided with the
    **     distribution.
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    **     contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
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    **
    ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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    import QtQuick 2.0
    import QtQuick.Particles 2.0

    ParticleSystem {
        id: sys
        width: 360
        height: 600
        running: true
        Rectangle {
            z: -1
            anchors.fill: parent
            color: "black"
        }

        property real petalLength: 180
        property real petalRotation: 0
        NumberAnimation on petalRotation {
            from: 0;
            to: 360;
            loops: -1;
            running: true
            duration: 24000
        }

        function convert(a) {return a*(Math.PI/180);}
        Emitter {
            lifeSpan: 4000
            emitRate: 120
            size: 12
            anchors.centerIn: parent
            onEmitParticles: {
                for (var i=0; i<particles.length; i++) {
                    var particle = particles[i];
                    particle.startSize = Math.max(02,Math.min(492,Math.tan(particle.t/2)*24));
                    var theta = Math.floor(Math.random() * 6.0);
                    particle.red = theta == 0 || theta == 1 || theta == 2 ? 0.2 : 1;
                    particle.green = theta == 2 || theta == 3 || theta == 4 ? 0.2 : 1;
                    particle.blue = theta == 4 || theta == 5 || theta == 0 ? 0.2 : 1;
                    theta /= 6.0;
                    theta *= 2.0*Math.PI;
                    theta += sys.convert(sys.petalRotation);//Convert from degrees to radians
                    particle.initialVX = petalLength * Math.cos(theta);
                    particle.initialVY = petalLength * Math.sin(theta);
                    particle.initialAX = particle.initialVX * -0.5;
                    particle.initialAY = particle.initialVY * -0.5;
                }
            }
        }

        ImageParticle {
            source: "qrc:///particleresources/fuzzydot.png"
            alpha: 0.0
        }
    }