import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import java.awt.image.*;

public class Applet1 extends Applet {
 Image image, image2;
 boolean halfFlg;

  boolean isStandalone = false;
  Button load = new Button();
  Button button2 = new Button();
  Button half = new Button();


  //アプレットの構築
  public Applet1() {
  }
  //アプレットの初期化
  public void init() {
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
  //コンポーネントの初期化
  private void jbInit() throws Exception {
    load.setLabel("load");
    load.setBounds(new Rectangle(15, 150, 80, 30));
    load.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        load_actionPerformed(e);
      }
    });
    this.setLayout(null);
    button2.setLabel("emboss");
    button2.setBounds(new Rectangle(100, 150, 80, 30));
    button2.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        button2_actionPerformed(e);
      }
    });
    half.setLabel("1/2");
    half.setBounds(new Rectangle(200, 150, 60, 30));
    half.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        half_actionPerformed(e);
      }
    });
    this.add(button2, null);
    this.add(load, null);
    this.add(half, null);
  }


  public void paint(Graphics g)
    {

        if(image != null ){
          int iwidth=image.getWidth(this);
          int iheight=image.getHeight(this);
          //System.out.println("size="+iwidth+" "+iheight);
          if( !halfFlg) g.drawImage(image, 0, 0, this);
           else  g.drawImage(image, 0, 0, iwidth/2,iheight/2,this);
      }
    }

  void load_actionPerformed(ActionEvent e) {
    //ファイルを読みpixels[]に記録する
    halfFlg=false;
    image = getImage(getDocumentBase(), "ccad.gif");
    //System.out.println("load="+image.getWidth(this)+" "+image.getHeight(this));
    repaint();
  }

  void button2_actionPerformed(ActionEvent e) {
       halfFlg=false;
       int iwidth=image.getWidth(this);
      int iheight=image.getHeight(this);
       //画素の配列
        int  pixels[] = new int[iwidth * iheight];
        //ファイルを読みpixels[]に記録する
       // System.out.println("edge="+image.getWidth(this)+" "+image.getHeight(this));
        PixelGrabber pg = new PixelGrabber(image, 0, 0, iwidth, iheight,pixels, 0, iwidth);
        try {
            pg.grabPixels();
        }
        catch (InterruptedException ev) {}
        //色別に微分処理をする
        for (int y = 2; y < iheight-1; y++){
            for (int x = 2; x < iwidth-1; x++){
               int  red = ((pixels[(y + 1) * iwidth + x + 1] & 0xFF)
                   - (pixels[y * iwidth + x] & 0xFF)) + 128;
                red = normal(red);
               int  green = (((pixels[(y + 1) * iwidth + x + 1] & 0xFF00) /0x100) % 0x100
                  - ((pixels[y *iwidth + x] & 0xFF00) /0x100) % 0x100) + 128;
                 green = normal(green);
               int  blue = (((pixels[(y + 1) * iwidth + x + 1] &0xFF0000) / 0x10000) % 0x100
                  - ((pixels[y * iwidth + x] &0xFF0000) / 0x10000) % 0x100) + 128;
                blue = normal(blue);
                //灰色にする
               int  avg = (red + green + blue) / 3;
               pixels[y * iwidth + x] = (0xff000000 | avg << 16 | avg << 8 | avg);
            }
        }
        //表示用imageにする
        //image2 = createImage(new MemoryImageSource(248, 248, pixels, 0 ,248));
        image = createImage(new MemoryImageSource(iwidth, iheight, pixels, 0 ,iwidth));
        repaint();
  }

  int normal(int col){//値を0..255の範囲にする
    if(col<0) return 0;
    if(col>255) return 255;
    return col;
    }

  void half_actionPerformed(ActionEvent e) {
    halfFlg=true;
    repaint();
  }

}