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

# velocityfrommotion.qml Example File

particles/emitters/content/velocityfrommotion.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.
    **   * Redistributions in binary form must reproduce the above copyright
    **     notice, this list of conditions and the following disclaimer in
    **     the documentation and/or other materials provided with the
    **     distribution.
    **   * Neither the name of The Qt Company Ltd nor the names of its
    **     contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
    **
    **
    ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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    ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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    import QtQuick 2.0
    import QtQuick.Particles 2.0

    Rectangle {

        id: root

        height: 540
        width: 360

        gradient: Gradient {
            GradientStop { position: 0; color: "#000020" }
            GradientStop { position: 1; color: "#000000" }
        }

        MouseArea {
            id: mouseArea
            anchors.fill: root
        }

        ParticleSystem { id: sys1 }
        ImageParticle {
            system: sys1
            source: "qrc:///particleresources/glowdot.png"
            color: "cyan"
            alpha: 0
            SequentialAnimation on color {
                loops: Animation.Infinite
                ColorAnimation {
                    from: "cyan"
                    to: "magenta"
                    duration: 1000
                }
                ColorAnimation {
                    from: "magenta"
                    to: "blue"
                    duration: 2000
                }
                ColorAnimation {
                    from: "blue"
                    to: "violet"
                    duration: 2000
                }
                ColorAnimation {
                    from: "violet"
                    to: "cyan"
                    duration: 2000
                }
            }
            colorVariation: 0.3
        }
        Emitter {
            id: trailsNormal
            system: sys1

            emitRate: 500
            lifeSpan: 2000

            y: mouseArea.pressed ? mouseArea.mouseY : circle.cy
            x: mouseArea.pressed ? mouseArea.mouseX : circle.cx

            velocity: PointDirection {xVariation: 4; yVariation: 4;}
            acceleration: PointDirection {xVariation: 10; yVariation: 10;}
            velocityFromMovement: 8

            size: 8
            sizeVariation: 4
        }
        ParticleSystem { id: sys2 }
        ImageParticle {
            color: "cyan"
            system: sys2
            alpha: 0
            SequentialAnimation on color {
                loops: Animation.Infinite
                ColorAnimation {
                    from: "magenta"
                    to: "cyan"
                    duration: 1000
                }
                ColorAnimation {
                    from: "cyan"
                    to: "magenta"
                    duration: 2000
                }
            }
            colorVariation: 0.5
            source: "qrc:///particleresources/star.png"
        }
        Emitter {
            id: trailsStars
            system: sys2

            emitRate: 100
            lifeSpan: 2200

            y: mouseArea.pressed ? mouseArea.mouseY : circle.cy
            x: mouseArea.pressed ? mouseArea.mouseX : circle.cx

            velocity: PointDirection {xVariation: 4; yVariation: 4;}
            acceleration: PointDirection {xVariation: 10; yVariation: 10;}
            velocityFromMovement: 8

            size: 22
            sizeVariation: 4
        }
        ParticleSystem { id: sys3; }
        ImageParticle {
            source: "qrc:///particleresources/glowdot.png"
            system: sys3
            color: "orange"
            alpha: 0
            SequentialAnimation on color {
                loops: Animation.Infinite
                ColorAnimation {
                    from: "red"
                    to: "green"
                    duration: 2000
                }
                ColorAnimation {
                    from: "green"
                    to: "red"
                    duration: 2000
                }
            }

            colorVariation: 0.2

        }
        Emitter {
            id: trailsNormal2
            system: sys3

            emitRate: 300
            lifeSpan: 2000

            y: mouseArea.pressed ? mouseArea.mouseY : circle2.cy
            x: mouseArea.pressed ? mouseArea.mouseX : circle2.cx

            velocityFromMovement: 16

            velocity: PointDirection {xVariation: 4; yVariation: 4;}
            acceleration: PointDirection {xVariation: 10; yVariation: 10;}

            size: 12
            sizeVariation: 4
        }
        ParticleSystem { id: sys4; }
        ImageParticle {
            system: sys4
            source: "qrc:///particleresources/star.png"
            color: "green"
            alpha: 0
            SequentialAnimation on color {
                loops: Animation.Infinite
                ColorAnimation {
                    from: "green"
                    to: "red"
                    duration: 2000
                }
                ColorAnimation {
                    from: "red"
                    to: "green"
                    duration: 2000
                }
            }

            colorVariation: 0.5
        }
        Emitter {
            id: trailsStars2
            system: sys4

            emitRate: 50
            lifeSpan: 2200

            y: mouseArea.pressed ? mouseArea.mouseY : circle2.cy
            x: mouseArea.pressed ? mouseArea.mouseX : circle2.cx

            velocityFromMovement: 16
            velocity: PointDirection {xVariation: 2; yVariation: 2;}
            acceleration: PointDirection {xVariation: 10; yVariation: 10;}

            size: 22
            sizeVariation: 4
        }

        color: "white"

        Item {
            id: circle
            //anchors.fill: parent
            property real radius: 0
            property real dx: root.width / 2
            property real dy: root.height / 2
            property real cx: radius * Math.sin(percent*6.283185307179) + dx
            property real cy: radius * Math.cos(percent*6.283185307179) + dy
            property real percent: 0

            SequentialAnimation on percent {
                loops: Animation.Infinite
                running: true
                NumberAnimation {
                duration: 1000
                from: 1
                to: 0
                loops: 8
                }
                NumberAnimation {
                duration: 1000
                from: 0
                to: 1
                loops: 8
                }

            }

            SequentialAnimation on radius {
                loops: Animation.Infinite
                running: true
                NumberAnimation {
                    duration: 4000
                    from: 0
                    to: 100
                }
                NumberAnimation {
                    duration: 4000
                    from: 100
                    to: 0
                }
            }
        }

        Item {
            id: circle3
            property real radius: 100
            property real dx: root.width / 2
            property real dy: root.height / 2
            property real cx: radius * Math.sin(percent*6.283185307179) + dx
            property real cy: radius * Math.cos(percent*6.283185307179) + dy
            property real percent: 0

            SequentialAnimation on percent {
                loops: Animation.Infinite
                running: true
                NumberAnimation { from: 0.0; to: 1 ; duration: 10000;  }
            }
        }

        Item {
            id: circle2
            property real radius: 30
            property real dx: circle3.cx
            property real dy: circle3.cy
            property real cx: radius * Math.sin(percent*6.283185307179) + dx
            property real cy: radius * Math.cos(percent*6.283185307179) + dy
            property real percent: 0

            SequentialAnimation on percent {
                loops: Animation.Infinite
                running: true
                NumberAnimation { from: 0.0; to: 1 ; duration: 1000; }
            }
        }

    }