Libgdx 之图片的翻转与旋转方式

在Libdgx 中经常会对图片进行翻转，旋转处理，很对时候是对资源的复用，一下是本文对图片进行处理的效果：

 region = Assets.testAtlas.findRegion("world1");

  TextureRegion region1 = new TextureRegion(region);

   TextureRegion region2 = new TextureRegion(region);

TextureRegion region3 = new TextureRegion(region);

翻转方法一：

使用 region3.flip(boolean, boolean) 进行上下左右翻转如image3

翻转方法二：

通过设置UV

  region2.setV(region.getV2());

        region2.setV2(region.getV());

      region1.setU(region.getU2());
        region1.setU2(region.getU());

这两种方法实质是一样的，都是通过setU setV setU2 setV2 实现翻转

值得注意的是，尽量避免直接对region进行翻转，Gdx底层通过Assets.testAtlas.findRegion("world1");方式，即使用AssetsManager 管理的纹理

都是定义成final类型，在别处使用的都是同一份内存。

图片旋转

如Imgae 4

使用batch 直接绘制资源，当然，可以翻转之后再进行绘制，绘制方法

batch.draw(region, x, y, originX, originY, width, height, scaleX, scaleY, rotation)

本文实现为

      batch.draw(region, getX(), getY(), getOriginX(), getOriginY(), getWidth(), getHeight(), getScaleX(), getScaleY(), getRotation());
 

全部实现代码

FlipDemo 主类

package com.whs.demo.application;

import com.badlogic.gdx.backends.jglfw.JglfwApplication;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.g2d.TextureRegion;
import com.badlogic.gdx.scenes.scene2d.Stage;
import com.badlogic.gdx.scenes.scene2d.ui.Image;
import com.badlogic.gdx.scenes.scene2d.ui.Label;
import com.badlogic.gdx.scenes.scene2d.ui.Label.LabelStyle;
import com.badlogic.gdx.scenes.scene2d.utils.Align;
import com.badlogic.gdx.utils.viewport.ScreenViewport;
import com.badlogic.gdx.utils.viewport.Viewport;
import com.whs.demo.Demo;
import com.whs.demo.assets.Assets;
import com.whs.demo.progress.ImageRotation;

public class FlipTest
    extends Demo {

    private TextureRegion region;
    private Stage stage;
    private OrthographicCamera camera;
    private Viewport viewport;
    

    @Override
    public void create() {
        super.create();
        Assets.init();
        Assets.loadAll();
        Assets.finishLoading();
        Assets.initTestAtlas();
        region = Assets.testAtlas.findRegion("world1");
        stage = new Stage();
        camera = new OrthographicCamera(WIDTH, HEIGHT);
        camera.position.set(WIDTH / 2, HEIGHT / 2, 0);
        viewport = new ScreenViewport(camera);
        viewport.setCamera(camera);
        stage.setViewport(viewport);
        camera.update();
        
        // 正常
        LabelStyle labelStyle = new Label.LabelStyle(Assets.font, Color.RED);
        Image image = new Image(region);
        image.setOrigin(Align.center);
        image.setPosition(0, 550F);
        Label label = new Label("image", labelStyle);
        label.setPosition(image.getX() + (image.getWidth() - label.getWidth()) / 2, image.getY() + image.getHeight());
        label.setAlignment(Align.center);
        label.setFontScale(0.5F);
        label.setScale(0.5F);
  
        
        stage .addActor(label);
        stage.addActor(image);
        
        // 水平翻转
        TextureRegion region1 = new TextureRegion(region);
        region1.setU(region.getU2());
        region1.setU2(region.getU());
        Image image1 = new Image(region1);
        image1.setPosition(image.getWidth() + 10, 550F);
        Label label1 = new Label("image1", labelStyle);
        label1.setPosition(image1.getX() + (image1.getWidth() - label1.getWidth()) / 2, image1.getY() + image1.getHeight());
        label1.setAlignment(Align.center);
        label1.setFontScale(0.5F);
        label1.setScale(0.5F);
        stage.addActor(image1);
        stage.addActor(label1);
        
        
        // 水平翻转
        TextureRegion region2 = new TextureRegion(region);
        region2.setV(region.getV2());
        region2.setV2(region.getV());
        Image image2 = new Image(region2);
        image2.setPosition(0 , 300F);
        Label label2 = new Label("image2", labelStyle);
        label2.setPosition(image2.getX() + (image2.getWidth() - label2.getWidth()) / 2, image2.getY() + image2.getHeight());
        label2.setAlignment(Align.center);
        label2.setFontScale(0.5F);
        label2.setScale(0.5F);
        stage.addActor(image2);
        stage.addActor(label2);
        
        
        
        // 水平翻转
        TextureRegion region3 = new TextureRegion(region);
        region3.flip(true, false);
        Image image3 = new Image(region3);
        image3.setPosition(image3.getWidth() + 10F , 300F);
        Label label3 = new Label("image3", labelStyle);
        label3.setPosition(image3.getX() + (image3.getWidth() - label3.getWidth()) / 2, image3.getY() + image3.getHeight());
        label3.setAlignment(Align.center);
        label3.setFontScale(0.5F);
        label3.setScale(0.5F);
        stage.addActor(image3);
        stage.addActor(label3);
        
        /**
         * 图片的旋转
         */
        ImageRotation image4 = new ImageRotation();
        image4.setOrigin(Align.center);
        image4.setRotation(60);
        image4.setPosition(0 + 10F , 50F);
        Label label4 = new Label("image4", labelStyle);
        label4.setPosition(image4.getX() + (image4.getWidth() - label3.getWidth()) / 2, image4.getY() + image4.getHeight());
        label4.setAlignment(Align.center);
        label4.setFontScale(0.5F);
        label4.setScale(0.5F);
        stage.addActor(image4);
        stage.addActor(label4);        
    }

    @Override
    public void render() {

        super.render();
        stage.act();
        stage.draw();
    }

    @Override
    public void dispose() {
        // TODO Auto-generated method stub
        super.dispose();

        stage.dispose();
        Assets.dispose();
    }

    public static void main(String[] args) {
        new JglfwApplication(new FlipTest(), "翻转测试 - By WHS", WIDTH , HEIGHT);
    }

}

ImageRotation类

package com.whs.demo.progress;

import com.badlogic.gdx.graphics.g2d.Batch;
import com.badlogic.gdx.graphics.g2d.TextureRegion;
import com.badlogic.gdx.scenes.scene2d.Actor;
import com.whs.demo.assets.Assets;


public class ImageRotation extends Actor {
    
    
    private TextureRegion region;


    public ImageRotation() {
        region = Assets.testAtlas.findRegion("world1");
        setSize(region.getRegionWidth() , region.getRegionHeight());
    }
    
    
    @Override
    public void draw(Batch batch, float parentAlpha) {
        // TODO Auto-generated method stub
        super.draw(batch, parentAlpha);
      
        batch.draw(region, getX(), getY(), getOriginX(), getOriginY(), getWidth(), getHeight(), getScaleX(), getScaleY(), getRotation());
    }
    

}