QML粒子系统

一、概念

粒子系统主要有四个QML类型，分别是ParticleSystem、Emitter、ParticlePainter和Affector。

ParticleSystem：是粒子系统，剩余几个类型需要绑定同一个粒子系统；

Emitter：粒子发射器；

ParticlePainter：粒子可视化方式；

Affector：控制已发射粒子的参数。

需要注意ParticlePainter有3个子类：

二、例子一：使用图片作为的效果粒子

1、下载star.png【例子并为加入到资源中】

2、代码1

import QtQuick 2.5
import QtQuick.Particles 2.0

Rectangle {
    id: root
     480; height: 160
    color: "#1f1f1f"

    ParticleSystem {
        id: particleSystem
    }

    Emitter {
        id: emitter
        anchors.centerIn: parent
         160; height: 80
        system: particleSystem
        emitRate: 10
        lifeSpan: 1000
        lifeSpanVariation: 500
        size: 16
        endSize: 32
    }

    ImageParticle {
//        source: "assets/particle.png"
        source: "assets/star.png"
        system: particleSystem
    }
}

效果

 3、代码2：加一点效果，颜色、旋转

import QtQuick 2.5
import QtQuick.Particles 2.0

Rectangle {
    id: root
     480; height: 160
    color: "#1F1F1F"

    ParticleSystem {
        id: particleSystem
    }
    ImageParticle {
        source: "assets/star.png"
        system: particleSystem

        color: '#FFD700'        //粒子初始颜色为金色
        colorVariation: 0.2     //不同粒子颜色变化范围+/-20%

        rotation: 0             //粒子初始角度
        rotationVariation: 45   //不同粒子初始角度+/-45

        rotationVelocity: 15    //粒子每秒旋转45度
        rotationVelocityVariation: 15   //不同粒子每秒旋转角度+/-15

        entryEffect: ImageParticle.Scale    //粒子入场效果为缩放
    }
    Emitter {
        id: emitter
        anchors.fill: parent
        system: particleSystem
        lifeSpan: 8000
        size: 32
        endSize: 16
    }
}

代码3：加一点效果，移动

import QtQuick 2.5
import QtQuick.Particles 2.0

Rectangle {
    id: root
     480; height: 240
    color: "#1F1F1F"

    ParticleSystem {
        id: particleSystem
    }

    ImageParticle {
        source: "assets/star.png"
        system: particleSystem
        color: '#FFD700'
        colorVariation: 0.2
        rotation: 0
        rotationVariation: 45
        rotationVelocity: 15
        rotationVelocityVariation: 15
        entryEffect: ImageParticle.Scale
    }

    Emitter {
        id: emitter
        anchors.left: parent.left
        anchors.verticalCenter: parent.verticalCenter
         1;
        height: 1
        system: particleSystem
        emitRate: 10
        lifeSpan: 6400
        lifeSpanVariation: 400
        size: 32
        velocity: TargetDirection {
            targetItem: target1
            targetVariation: 20
            magnitude: 50
        }
        acceleration: TargetDirection {
            targetItem: target2
            targetVariation: 20
            magnitude: 50
        }
    }

    Rectangle {
        id: target1
         40; height: width
        radius: width/2
        color: '#FF0000'
        opacity: 0.5
        MouseArea {
            anchors.fill: parent
            drag.target: target1
        }
    }

    Rectangle {
        id: target2
         40; height: width
        radius: width/2
        color: '#00FF00'
        opacity: 0.5
        MouseArea {
            anchors.fill: parent
            drag.target: target2
        }
    }
}