customemitter.qml Example File

particles/emitters/content/customemitter.qml
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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
     }
 }