e669. drawing on a buffered image.txt

来自「这里面包含了一百多个JAVA源文件」· 文本 代码 · 共 20 行

To draw on a buffered image, create a graphics context on the buffered image. 
    // Create a graphics context on the buffered image
    Graphics2D g2d = bimage.createGraphics();
    
    // Draw on the image
    g2d.setColor(Color.red);
    g2d.fill(new Ellipse2D.Float(0, 0, 200, 100));
    g2d.dispose();

If the buffered image supports transparency, (see e661 Determining If an Image Has Transparent Pixels), pixels can be made transparent: 
    g2d = bimage.createGraphics();
    
    // Make all filled pixels transparent
    Color transparent = new Color(0, 0, 0, 0);
    g2d.setColor(transparent);
    g2d.setComposite(AlphaComposite.Src);
    g2d.fill(new Rectangle2D.Float(20, 20, 100, 20));
    g2d.dispose();