-2

用 Java 构建彩票刮刮卡应用程序。已完成分配，只需要有关刮擦功能的帮助。

基本上程序是这样工作的：

  1. 为背景创建图像（现在它只是一个白色背景，但后来显然是带有乐透符号的刮刮卡图像）
  2. 创建card_surface，它只是一个绿色层，在刮擦时应该显示后面的图像。
  3. onMouseDragged() 我用一个笔划从当前鼠标坐标到新的鼠标坐标画了一条线。我尝试在此笔画上设置 Alphacomposite，认为它会显示下面的图像。不幸的是，不是。

感谢任何帮助...

 import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;

import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.ImageIcon;

import java.awt.Stroke;
import java.awt.BasicStroke;
import java.awt.AlphaComposite;


public class Main {
  public static void main(String[] args) {
    JFrame frame = new JFrame();
    final DrawPad drawPad = new DrawPad();
    frame.add(drawPad, BorderLayout.CENTER);
    JButton clearButton = new JButton("New Scratch-Card");
    clearButton.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        drawPad.clear();
      }
    });
    frame.add(clearButton, BorderLayout.SOUTH);
    frame.setSize(500, 300);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
  }

}
class DrawPad extends JComponent {
  Image image;
  Image card_surface;

  Graphics2D graphics2D;
  int currentX, currentY, oldX, oldY;



  public DrawPad() {
    final Stroke stroke = new BasicStroke (17.0F, BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL);
    //image = new ImageIcon("iPhone-4-Pattern-Wallpaper-07.jpg").getImage();
    setDoubleBuffered(false);
    addMouseListener(new MouseAdapter() {
      public void mousePressed(MouseEvent e) {
        oldX = e.getX();
        oldY = e.getY();
      }
    });
    addMouseMotionListener(new MouseMotionAdapter() {
      public void mouseDragged(MouseEvent e) {
        currentX = e.getX();
        currentY = e.getY();
        if (graphics2D != null){
      graphics2D.setStroke(stroke);
          graphics2D.setPaint(Color.GRAY);
          graphics2D.setComposite(makeComposite(0.5F));
          graphics2D.drawLine(oldX, oldY, currentX, currentY);
        repaint();
        oldX = currentX;
        oldY = currentY;
      }
}
    });
  }
private AlphaComposite makeComposite(float alpha) {
    int type = AlphaComposite.SRC_OVER;
    return(AlphaComposite.getInstance(type, alpha));
  }
 public void clear() {
    image=null;
    card_surface=null;

    repaint();
  }
  public void paintComponent(Graphics g) {
    if (image == null) {

      image = createImage(getSize().width, getSize().height);
      graphics2D = (Graphics2D) image.getGraphics();
      graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
          RenderingHints.VALUE_ANTIALIAS_ON);



    graphics2D.setPaint(Color.white);
        graphics2D.fillRect(0, 0, getSize().width, getSize().height);
        graphics2D.setPaint(Color.black);

    repaint();

    }

     if (card_surface == null) {
    card_surface = createImage(getSize().width, getSize().height);
        graphics2D = (Graphics2D) card_surface.getGraphics();
        graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
      RenderingHints.VALUE_ANTIALIAS_ON);   

    graphics2D.setPaint(Color.green);
        graphics2D.fillRect(0, 0, getSize().width, getSize().height);

    repaint();
}


    g.drawImage(image, 0, 0, null);
    g.drawImage(card_surface, 0, 0, null);

  }


}
4

2 回答 2

4

您要做的是在用户“刮擦”顶部图像时显示底层图像，对吗？

您实际上需要两个图像：首先是原始图像，其次是带有灰色背景的空白图像，该图像覆盖第一张图像，将其隐藏。当用户“刮擦”顶部图像时，您需要在灰色图像上用透明颜色绘制，露出底层图像。

所以步骤是：

绘制带有空白的原始图像当用户在顶部图像上使用透明颜色绘制时重新绘制图像，顶部图像现在具有透明部分重复

这听起来很复杂，但我认为这不会太难，您只需将两个图像分开并使用缓冲区在另一个上绘制。有关使用透明缓冲图像的信息，请参阅这篇文章如何在 BufferedImage 中使颜色透明并另存为 PNG。

我希望这有帮助。

于 2011-12-29T08:30:07.137 回答
0

好的设法让基础工作，

我使用了 Ewald 的链接，谢谢伙计！

这是工作代码（只需将“iphone4”图像路径更改为您选择的图像）：

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;

import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.ImageIcon;
import java.awt.image.BufferedImage;
import java.awt.image.FilteredImageSource;
import java.awt.image.ImageFilter;
import java.awt.image.ImageProducer;
import java.awt.image.RGBImageFilter;
import java.awt.Toolkit;
import java.io.File;
import javax.imageio.ImageIO;

import java.awt.Stroke;
import java.awt.BasicStroke;
import java.awt.AlphaComposite;


public class Main {
  public static void main(String[] args) {
    JFrame frame = new JFrame();
    final DrawPad drawPad = new DrawPad();
    frame.add(drawPad, BorderLayout.CENTER);
    JButton clearButton = new JButton("New Scratch-Card");
    clearButton.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        drawPad.clear();
      }
    });
    frame.add(clearButton, BorderLayout.SOUTH);
    frame.setSize(500, 300);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
  }

}
class DrawPad extends JComponent {
  BufferedImage image;
  BufferedImage card_surface;

  Graphics2D graphics2D;
  int currentX, currentY, oldX, oldY;



  public DrawPad() {
    final Stroke stroke = new BasicStroke (17.0F, BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL);

    setDoubleBuffered(false);
    addMouseListener(new MouseAdapter() {
      public void mousePressed(MouseEvent e) {
        oldX = e.getX();
        oldY = e.getY();
      }
    });
    addMouseMotionListener(new MouseMotionAdapter() {
      public void mouseDragged(MouseEvent e) {
        currentX = e.getX();
        currentY = e.getY();
        if (graphics2D != null){
      graphics2D.setStroke(stroke);
          graphics2D.setPaint(Color.GRAY);
          //graphics2D.setComposite(makeComposite(0.5F));
          graphics2D.drawLine(oldX, oldY, currentX, currentY);
        repaint();
        oldX = currentX;
        oldY = currentY;
      }
}
    });
  }
private AlphaComposite makeComposite(float alpha) {
    int type = AlphaComposite.SRC_OVER;
    return(AlphaComposite.getInstance(type, alpha));
  }
 private Image TransformColorToTransparency(BufferedImage image, Color c1, Color c2)
  {
    // Primitive test, just an example
    final int r1 = c1.getRed();
    final int g1 = c1.getGreen();
    final int b1 = c1.getBlue();
    final int r2 = c2.getRed();
    final int g2 = c2.getGreen();
    final int b2 = c2.getBlue();
    ImageFilter filter = new RGBImageFilter()
    {
      public final int filterRGB(int x, int y, int rgb)
      {
        int r = (rgb & 0xFF0000) >> 16;
        int g = (rgb & 0xFF00) >> 8;
        int b = rgb & 0xFF;
        if (r >= r1 && r <= r2 &&
            g >= g1 && g <= g2 &&
            b >= b1 && b <= b2)
        {
          // Set fully transparent but keep color
          return rgb & 0xFFFFFF;
        }
        return rgb;
      }
    };

    ImageProducer ip = new FilteredImageSource(image.getSource(), filter);
      return Toolkit.getDefaultToolkit().createImage(ip);
  }
private BufferedImage ImageToBufferedImage(Image image2, int width, int height)
  {
    BufferedImage dest = new BufferedImage(
        width, height, BufferedImage.TYPE_INT_ARGB);
    Graphics2D g2 = dest.createGraphics();
    //g2.drawImage(image, 0, 0, null);
    g2.drawImage(image2, 0, 0, null);
    //g2.dispose();
    return dest;
  }
 public void clear() {
    image=null;
    card_surface=null;

    repaint();
  }
  public void paintComponent(Graphics g) {



 if (image == null) {

    image = new BufferedImage(500, 300, BufferedImage.TYPE_INT_ARGB);
    String imagePath = "iPhone-4-Pattern-Wallpaper-07.jpg";
    File inFile = new File(imagePath);
    try{
    image = ImageIO.read(inFile);
}catch(java.io.IOException e){System.out.println(e);}


    graphics2D = image.createGraphics();

      //image = new ImageIcon().getImage("");
      //image = createImage(getSize().width, getSize().height);
      //graphics2D = (Graphics2D) image.getGraphics();
      graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
          RenderingHints.VALUE_ANTIALIAS_ON);



    //graphics2D.setPaint(Color.white);
       // graphics2D.fillRect(0, 0, getSize().width, getSize().height);
       // graphics2D.setPaint(Color.black);

    repaint();

    }

     if (card_surface == null) {
    card_surface = new BufferedImage(500, 300, BufferedImage.TYPE_INT_ARGB);
        graphics2D = (Graphics2D) card_surface.getGraphics();
        graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
      RenderingHints.VALUE_ANTIALIAS_ON);   

    graphics2D.setPaint(Color.green);
        graphics2D.fillRect(0, 0, getSize().width, getSize().height);

    repaint();
}


    g.drawImage(image, 0, 0, null);
    g.drawImage(card_surface, 0, 0, null);
    Image transpImg2 = TransformColorToTransparency(card_surface, new Color(0, 50, 77), new Color(200, 200, 255));
    BufferedImage resultImage2 = ImageToBufferedImage(transpImg2, image.getWidth(), image.getHeight());
    g.drawImage(image, 0, 0, null);
    g.drawImage(resultImage2, 0, 0, null); 

   /* File outFile2 = new File("map_with_transparency2.png");
    try{
    ImageIO.write(resultImage2, "PNG", outFile2);
    }catch(Exception e){System.out.println(e);}
    //card_surface = (BufferedImage)transpImg2;
    */
  }


}
于 2011-12-30T02:21:31.083 回答