The design of animation in the game is very important. In QML, it provides a rich animation, but sometimes we need to change the image, just like a movie. In today’s article, we will design an animation that can change the image. This can be done with Sprite features provided by Qt. \
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For the convenience of design, we first design a bear animation of our own. The image size of this animation is 2048×256. It happens to be 8 copies 256×256
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In our Sprite design, we wanted to display each image in the same order as the above, so that we could create a continuously changing animation.
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Post our animation design file BearSprite directly:
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BearSprite.qml
Import QtQuick 2.0 Item {width: 256 height: 256 SpriteSequence {id: fishSprite anchors. Fill: parent interpolate: false goalSprite: "" Sprite { name: "first" source: "./gfx/Bear2.png" frameWidth: 256 frameHeight: 256 frameCount: 1 frameDuration: 800 frameDurationVariation: 400 to: { "second" : 1 } } Sprite { name: "second" source: "./gfx/Bear2.png" frameCount: 1 frameX: 256 frameWidth: 256 frameHeight: 256 frameDuration: 800 frameDurationVariation: 400 to: { "third" : 1 } } Sprite { name: "third" source: "./gfx/Bear2.png" frameCount: 1 frameX: 256*2 frameWidth: 256 frameHeight: 256 frameDuration: 800 frameDurationVariation: 400 to: { "fourth" : 1 } } Sprite { name: "fourth" source: "./gfx/Bear2.png" frameCount: 1 frameX: 256*3 frameWidth: 256 frameHeight: 256 frameDuration: 800 frameDurationVariation: 400 to: { "fifth" : 1 } } Sprite { name: "fifth" source: "./gfx/Bear2.png" frameCount: 1 frameX: 256*4 frameWidth: 256 frameHeight: 256 frameDuration: 800 frameDurationVariation: 400 to: { "sixth" : 1 } } Sprite { name: "sixth" source: "./gfx/Bear2.png" frameCount: 1 frameX: 256*5 frameWidth: 256 frameHeight: 256 frameDuration: 800 frameDurationVariation: 400 to: { "seventh" : 1 } } Sprite { name: "seventh" source: "./gfx/Bear2.png" frameCount: 1 frameX: 256*6 frameWidth: 256 frameHeight: 256 frameDuration: 800 frameDurationVariation: 400 to: { "eighth" : 1 } } Sprite { name: "eighth" source: "./gfx/Bear2.png" frameCount: 1 frameX: 256*7 frameWidth: 256 frameHeight: 256 frameDuration: 800 frameDurationVariation: 400 to: { "first" : 1 } } Sprite { //WORKAROUND: This prevents the triggering of a rendering error which is currently under investigation. name: "dummy" source: "./gfx/Bear2.png" frameCount: 8 frameWidth: 256 frameHeight: 256 frameX: 0 frameDuration: 200 } } }Copy the code\
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In the above design, we used a SpriteSequence with a few sprites in it.
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Sprite {
name: "sixth"
source: "./gfx/Bear2.png"
frameCount: 1
frameX: 256*5
frameWidth: 256
frameHeight: 256
frameDuration: 800
frameDurationVariation: 400
to: { "seventh" : 1 }
}
Copy the codeEvery Sprite here is pretty much the same design. Each Sprite has its own name. Note the frameX here. It’s actually the x-coordinate position that we showed above. So 256×5, for example, is drip-5. In addition, our frameHeight and frameWidth are the same size as the original image, although in the actual display this size can be set in main.qml.
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Using the same method, we can make a FishSprite.
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FishSprite.qml
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Import QtQuick 2.0 import QtMultimedia 5.0 Item {width: 64 height: 64 property real HP: 3 SoundEffect {id: spawnSound source: "./audio/catch.wav" loops:SoundEffect.Infinite } SoundEffect { id: killedSound source: "./audio/catch-action.wav" } SpriteSequence { id: fishSprite anchors.fill: parent interpolate: false goalSprite: "" Sprite { name: "left" source: "./gfx/mob-idle.png" frameWidth: 64 frameHeight: 64 frameCount: 1 frameDuration: 800 frameDurationVariation: 400 to: { "front" : 1 } } Sprite { name: "front" source: "./gfx/mob-idle.png" frameCount: 1 frameX: 64 frameWidth: 64 frameHeight: 64 frameDuration: 800 frameDurationVariation: 400 to: { "left" : 1, "right" : 1 } } Sprite { name: "right" source: "./gfx/mob-idle.png" frameCount: 1 frameX: 128 frameWidth: 64 frameHeight: 64 frameDuration: 800 frameDurationVariation: 400 to: { "front" : 1 } } Sprite { //WORKAROUND: This prevents the triggering of a rendering error which is currently under investigation. name: "dummy" source: "./gfx/melee-idle.png" frameCount: 8 frameWidth: 64 frameHeight: 64 frameX: 0 frameDuration: 200 } NumberAnimation on x { id: fishSwim running: false property bool goingLeft: fishSprite.currentSprite == "right" to: goingLeft ? -360 : 360 duration: 300 } Component.onCompleted: { spawnSound.play() } } SpriteSequence { id: bubble width: 64 height: 64 Scale: 0.4 + (0.2 * HP) interpolate: false goalSprite: "" Behavior on scale {NumberAnimation {duration: 150; easing.type: Easing.OutBack } } Sprite { name: "big" source: "./gfx/catch.png" frameCount: 1 to: { "burst" : 0 } } Sprite { name: "burst" source: "./gfx/catch-action.png" frameCount: 3 frameX: 64 frameDuration: 200 } Sprite { //WORKAROUND: This prevents the triggering of a rendering error which is currently under investigation. name: "dummy" source: "./gfx/melee-idle.png" frameCount: 8 frameWidth: 64 frameHeight: 64 frameX: 0 frameDuration: 200 } SequentialAnimation on width { loops: Animation.Infinite NumberAnimation { from: width * 1; To: width * 1.1; duration: 800; Type: easing. InOutQuad} NumberAnimation {from: width * 1.1; to: width * 1; duration: 1000; easing.type: Easing.InOutQuad } } SequentialAnimation on height { loops: Animation.Infinite NumberAnimation { from: height * 1; To: height * 1.15; duration: 1200; Type: easing. InOutQuad} NumberAnimation {from: height * 1.15; to: height * 1; duration: 1000; easing.type: Easing.InOutQuad } } } }Copy the code\
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Main.qml
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Import QtQuick 2.0 import Ubuntu.Components 1.1 /*! \brief MainView with a Label and Button elements. */ MainView { // objectName for functional testing purposes (autopilot-qt5) objectName: "mainView" // Note! applicationName needs to match the "name" field of the click manifest applicationName: "sprite.liu-xiao-guo" /* This property enables the application to change orientation when the device is rotated. The default is false. */ //automaticOrientation: true // Removes the old toolbar and enables new features of the new header. useDeprecatedToolbar: false width: units.gu(60) height: units.gu(85) Page { id: page title: i18n.tr("sprite") Column { anchors.fill: parent FishSprite { height: units.gu(30) width: units.gu(30) } BearSprite { id: bear height: units.gu(30) width: units.gu(30) NumberAnimation on x { to: page.width duration: 8*800 onRunningChanged: { if ( running == false) { bear.x = 0 start() } } } } } } }Copy the code\
To run our QML application:
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Project source at: github.com/liu-xiao-gu…
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