使用AffineTransform旋转图像

Question

我上课了Airplane。在这个类中，我有img一个BufferedImage类型的变量。更重要的是，我有WorldMap重写功能的类paintComponent(Graphics g)：@Overridepublic void paintComponent(Graphics g) {    Graphics2D g2d = (Graphics2D) g;    g2d.drawImage(mapa, 0, 0, getWidth(), getHeight(), null);     drawAirplanes(g2d);}函数drawAirplanes()看起来像这样：private void drawAirplane(Graphics2D g){    for(Samolot i: s){        i.rotateAirplane();        g.drawImage(i.getImg(),i.getX(),i.getY(),(int)i.getDim().getWidth(),(int)i.getDim().getHeight(),  null);    }}它只需要1）旋转飞机（飞机对象内部的BufferedImage）2）画他。我的Airplane.rotateAirplane（）函数如下所示： public void rotateSamolot() {   AffineTransform tx = new AffineTransform();   tx.translate(10,10); //10, 10 is height and width of img divide by 2   tx.rotate(Math.PI / 2);   tx.translate(-10,-10);    AffineTransformOp op = new AffineTransformOp(tx, AffineTransformOp.TYPE_BILINEAR);   BufferedImage newImage =new BufferedImage(20, 20, img.getType()); //20, 20 is a height and width of img ofc   op.filter(img, newImage);       this.img = newImage; }我运行我的程序时，只有ofc mapa对象被绘制。当我删除此车道时this.img = newImage;我也有我的飞机，但是没有旋转。

Answer 1

这是对我有用的（从这里到那里复制副本）：

public BufferedImage rotateImag (BufferedImage imag, int n) { //n rotation in gradians

        double rotationRequired = Math.toRadians (n);

        double locationX = imag.getWidth() / 2;

        double locationY = imag.getHeight() / 2;

        AffineTransform tx = AffineTransform.getRotateInstance(rotationRequired, locationX, locationY);

        AffineTransformOp op = new AffineTransformOp(tx, AffineTransformOp.TYPE_BILINEAR);         

       BufferedImage newImage =new BufferedImage(imag.getWidth(), imag.getHeight(), imag.getType()); //20, 20 is a height and width of imag ofc

       op.filter(imag, newImage);

           //this.img = newImage;

       return(newImage);

     }