java - 保存文件之前 Graphic2D 旋转

Question

我使用 g2d 创建此图像:

这是代码:

BufferedImage bufferedImage = new BufferedImage(408, 408, BufferedImage.TYPE_INT_RGB);    
Graphics2D g2d = bufferedImage.createGraphics();
List<Pixel> pixels = cacheRepo.findAll();
pixels.stream().forEach(pixel -> {
    g2d.setColor(getColorFromPixel(pixel));
    g2d.fillRect(getPos(pixel.getPosition().x), getPos(pixel.getPosition().y), 20, 20);
});

现在我尝试将其旋转 90° anticlok，以便蓝色方 block 出现在左下角:

所以我添加这个:

g2d.rotate(Math.toRadians(90));
g2d.drawRenderedImage(bufferedImage, null);

但是旋转没有发生(我仍然有相同的图像)。

这是完整的代码，其中包含保存图像的部分:

 // Constructs a BufferedImage of one of the predefined image types.
    BufferedImage bufferedImage = new BufferedImage(408, 408, BufferedImage.TYPE_INT_RGB);
    // Create a graphics which can be used to draw into the buffered image
    Graphics2D g2d = bufferedImage.createGraphics();
    List<Pixel> pixels = cacheRepo.findAll();
    pixels.stream().forEach(pixel -> {
        g2d.setColor(getColorFromPixel(pixel));
        g2d.fillRect(getPos(pixel.getPosition().x), getPos(pixel.getPosition().y), 20, 20);
    });
    g2d.rotate(Math.toRadians(90));
    g2d.drawRenderedImage(bufferedImage, null);
    g2d.dispose();
    // Save as PNG
    File file = new File("myimage.png");
    try {
        ImageIO.write(bufferedImage, "png", file);
    } catch (IOException e) {
        e.printStackTrace();
    }

Answer 1

转换应该在您希望受其影响的任何操作之前应用，转换不会影响之前完成的任何操作...

BufferedImage bufferedImage = new BufferedImage(408, 408, BufferedImage.TYPE_INT_RGB);
// Create a graphics which can be used to draw into the buffered image
Graphics2D g2d = bufferedImage.createGraphics();
g2d.rotate(Math.toRadians(90));
List<Pixel> pixels = cacheRepo.findAll();
pixels.stream().forEach(pixel -> {
    g2d.setColor(getColorFromPixel(pixel));
    g2d.fillRect(getPos(pixel.getPosition().x), getPos(pixel.getPosition().y), 20, 20);
});
//g2d.rotate(Math.toRadians(90));
// Not sure what you're hoping to achieve here
//g2d.drawRenderedImage(bufferedImage, null);
g2d.dispose();

如果您愿意，可以使用两个BufferedImages。将“正常”内容渲染到第一个内容，然后使用第二个内容来绘制第一个内容，但要进行旋转变换...因为变换使我的头陷入了😝

using your code draw a black image

您可能需要提供一个可以围绕图像旋转的 anchor ，否则它将围绕左上角/左上角进行评级

你会原谅我的，但这种想法以前也不是没有被问过

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