- Qt 5.3
- Qt Quick
- Qt Quick Particles Examples - Affectors
- customaffector.qml Example File
- Qt 5.3.2 Reference Documentation

# customaffector.qml Example File

particles/affectors/content/customaffector.qml

    /****************************************************************************
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    ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
    ** Contact: http://www.qt-project.org/legal
    **
    ** 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
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    **   * Redistributions of source code must retain the above copyright
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    **     of its contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
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    import QtQuick 2.0
    import QtQuick.Particles 2.0

    Item {
        width: 360
        height: 600

        Image {
            source: "../../images/backgroundLeaves.jpg"
            anchors.fill: parent
        }
        ParticleSystem {
            anchors.fill: parent
            Emitter {
                width: parent.width
                emitRate: 4
                lifeSpan: 14000
                size: 80
                velocity: PointDirection { y: 60 }
            }
            Wander {
                anchors.fill: parent
                anchors.bottomMargin: 100
                xVariance: 60
                pace: 60
            }

            Affector {
                property real coefficient: 0.1
                property real velocity: 1.5
                width: parent.width
                height: parent.height - 100
                onAffectParticles: {
                /*  //Linear movement
                    if (particle.r == 0) {
                        particle.r = Math.random() > 0.5 ? -1 : 1;
                    } else if (particle.r == 1) {
                        particle.rotation += velocity * dt;
                        if (particle.rotation >= maxAngle)
                            particle.r = -1;
                    } else if (particle.r == -1) {
                        particle.rotation -= velocity * dt;
                        if (particle.rotation <= -1 * maxAngle)
                            particle.r = 1;
                    }
                */
                    //Wobbly movement
                    for (var i=0; i<particles.length; i++) {
                        var particle = particles[i];
                        if (particle.r == 0.0) {
                            particle.r = Math.random() + 0.01;
                        }
                        particle.rotation += velocity * particle.r * dt;
                        particle.r -= particle.rotation * coefficient;
                        if (particle.r == 0.0)
                            particle.r -= particle.rotation * 0.000001;
                        particle.update = 1;
                    }
                }
            }

            Affector {//Custom Friction, adds some 'randomness'
                x: -60
                width: parent.width + 120
                height: 100
                anchors.bottom: parent.bottom
                onAffectParticles: {
                    for (var i=0; i<particles.length; i++) {
                        var particle = particles[i];
                        var pseudoRand = (Math.floor(particle.t*1327) % 10) + 1;
                        var yslow = dt * pseudoRand * 0.5 + 1;
                        var xslow = dt * pseudoRand * 0.05 + 1;
                        if (particle.vy < 1)
                            particle.vy = 0;
                        else
                            particle.vy = (particle.vy / yslow);
                        if (particle.vx < 1)
                            particle.vx = 0;
                        else
                            particle.vx = (particle.vx / xslow);
                        particle.update = true;
                    }
                }
            }

            ImageParticle {
                anchors.fill: parent
                id: particles
                sprites: [Sprite {
                        source: "../../images/realLeaf1.png"
                        frameCount: 1
                        frameDuration: 1
                        to: {"a":1, "b":1, "c":1, "d":1}
                    }, Sprite {
                        name: "a"
                        source: "../../images/realLeaf1.png"
                        frameCount: 1
                        frameDuration: 10000
                    },
                    Sprite {
                        name: "b"
                        source: "../../images/realLeaf2.png"
                        frameCount: 1
                        frameDuration: 10000
                    },
                    Sprite {
                        name: "c"
                        source: "../../images/realLeaf3.png"
                        frameCount: 1
                        frameDuration: 10000
                    },
                    Sprite {
                        name: "d"
                        source: "../../images/realLeaf4.png"
                        frameCount: 1
                        frameDuration: 10000
                    }
                ]

                z:4
            }
        }
    }